U.S. patent application number 08/982629 was filed with the patent office on 2002-07-04 for image sensing apparatus for sensing moving and still images.
Invention is credited to HIRASAWA, MASAHIDE, KUROBE, MASAKAZU, NAKAYAMA, SATOSHI.
Application Number | 20020085099 08/982629 |
Document ID | / |
Family ID | 27531128 |
Filed Date | 2002-07-04 |
United States Patent
Application |
20020085099 |
Kind Code |
A1 |
HIRASAWA, MASAHIDE ; et
al. |
July 4, 2002 |
IMAGE SENSING APPARATUS FOR SENSING MOVING AND STILL IMAGES
Abstract
There is disclosed a video camera which has a normal moving
image sensing mode, and a still image sensing mode for sensing an
image on a negative film set in a film adapter attached as a still
image. An optical image of a subject is photoelectrically converted
into an image signal, and whether or not the subject is a negative
film is detected on the basis of a predetermined signal component
in the image signal. If it is detected that the subject is the
negative film, the still image sensing mode starts while setting
signal processing in a negative/positive conversion mode and
setting the focal length of the lens system at the wide-angle
position.
Inventors: |
HIRASAWA, MASAHIDE;
(SAGAMIHARA-SHI, JP) ; KUROBE, MASAKAZU;
(KAWASAKI-SHI, JP) ; NAKAYAMA, SATOSHI;
(YOKOHAMA-SHI, JP) |
Correspondence
Address: |
MORGAN AND FINNEGAN
345 PARK AVENUE
NEW YORK
NY
10154
|
Family ID: |
27531128 |
Appl. No.: |
08/982629 |
Filed: |
December 2, 1997 |
Current U.S.
Class: |
348/222.1 ;
348/234; 348/E5.049 |
Current CPC
Class: |
H04N 5/253 20130101 |
Class at
Publication: |
348/222 ;
348/234; 348/220 |
International
Class: |
H04N 005/225 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 1996 |
JP |
8-322714 |
Dec 3, 1996 |
JP |
8-322716 |
Dec 16, 1996 |
JP |
8-335777 |
Dec 17, 1996 |
JP |
8-336840 |
Dec 26, 1996 |
JP |
8-356507 |
Claims
What is claimed is:
1. An image sensing apparatus which has a moving image sensing mode
and still image sensing mode, and can sense a close subject image,
comprising: image sensing means for outputting an image signal by
photoelectrically converting an optical image of a subject;
detection means for detecting based on a predetermined signal
component in the image signal if the subject is close to said
apparatus; and control means for, when said detection means detects
that the subject is close to said apparatus, setting said image
sensing apparatus in the still image sensing mode.
2. The apparatus according to claim 1, wherein said detection means
detects based on chrominance signal components in the image signal
if the subject is a negative film.
3. The apparatus according to claim 2, wherein further comprising:
first luminance component generation means for generating a
luminance signal component on the basis of the image signal; first
chrominance component generation means for generating chrominance
components on the basis of the image signal; second luminance
component generation means for generating a luminance component by
reversing light and dark portions in correspondence with a
luminance level of the image signal; and second chrominance
component generation means for generating chrominance components in
accordance with the chrominance components of the image signal
using a predetermined conversion scheme, and wherein when said
detection means detects that the subject is not a negative film,
said control means controls to generate a video signal using output
signals from said first luminance component generation means and
first chrominance component generation means, and when said
detection means detects that the subject is a negative film, said
control means controls to generate a video signal using output
signals from said second luminance component generation means and
second chrominance component generation means.
4. The apparatus according to claim 1, wherein a film adapter for
holding a subject such as a film or the like can be detachably
attached to said image sensing apparatus, and when said film
adapter is attached, it is determined that the film held by said
film adapter is close to said apparatus.
5. An image sensing apparatus comprising: image sensing means for
outputting a first image signal by photoelectrically converting an
optical image formed via an image sensing optical system; signal
processing means for generating a second image signal by performing
predetermined processing of the first image signal; and film image
sensing means for sensing a film image by mounting a film image
sensing adapter, wherein said signal processing means comprises:
first luminance component generation means for generating a
luminance component of the second image signal in accordance with a
luminance level of the first image signal; first chrominance
component generation means for generating chrominance components of
the second image signal in accordance with chrominance components
of the first image signal; second luminance component generation
means for generating a luminance component of the second image
signal by reversing light and dark portions in accordance with a
luminance level of the first image signal; second chrominance
component generation means for generating chrominance components of
the second image signal in accordance with chrominance components
of the first image signal using a predetermined conversion scheme;
and control means which can select one of a moving image sensing
mode for sensing a moving image, and a film image sensing mode for
sensing a photographic film image using said film image sensing
means, and selects the film image sensing mode when the second
image signal is generated using output signals from said second
luminance component generation means and second chrominance
component generation means.
6. The apparatus according to claim 5, further comprising: color
identification means for identifying a color of the subject on the
basis of information associated with a color of the first image
signal, and wherein said control means selects on the basis of an
identification result of said color identification means whether
the second image signal is generated by said first luminance
component generation means and first chrominance component
generation means, or by said second luminance component generation
means and second chrominance component generation means, and
selects the film image sensing mode upon selecting second image
signal generation using said second luminance component generation
means and second chrominance component generation means.
7. The apparatus according to claim 5, wherein said second
luminance component generation means and second chrominance
component generation means output a negative-to-positive reversed
second image signal.
8. An image sensing apparatus comprising: an image sensing optical
system which changes a position of a lens in correspondence with a
subject distance; position detection means for detecting the
position of the lens; image sensing means for outputting a first
image signal by photoelectrically converting an optical image of a
subject imaged via said image sensing optical system; and control
means which can select one of a plurality of image sensing modes
including a moving image sensing mode for sensing a moving image
and a film image sensing mode for sensing a close subject such as a
film, and sets an image sensing mode in the film image sensing mode
when the lens is located at a predetermined position.
9. The apparatus according to claim 8, wherein said control means
sets the film image sensing mode when the lens is located within a
predetermined range on the closest distance side.
10. The apparatus according to claim 9, wherein said image sensing
optical system comprises a magnification lens, and said control
means sets the film image sensing mode when said magnification lens
is located at a predetermined position on the wide-angle side, and
the lens is located within a predetermined range on the closest
distance side.
11. The apparatus according to claim 8, wherein a film adapter for
holding a subject such as a film can be detachably attached to a
predetermined position of a front portion of said image sensing
optical system, and the film image sensing mode is enabled by
attaching said film adapter.
12. An image sensing apparatus comprising: an image sensing optical
system which changes a position of a lens in correspondence with a
subject distance; position detection means for detecting the
position of the lens; image sensing means for outputting an image
signal by photoelectrically converting an optical image of a
subject imaged via said image sensing optical system; and control
means which can select one of a plurality of image sensing modes
including a moving image sensing mode for sensing a moving image
and a still image sensing mode for sensing a still image, and sets
an image sensing mode in the still image sensing mode when the lens
is located at a predetermined position.
13. The apparatus according to claim 12, wherein said control means
sets the still image sensing mode when the lens is located with a
predetermined range on the closest distance side.
14. The apparatus according to claim 13, wherein said image sensing
optical system comprises a magnification lens, and said control
means sets the still image sensing mode when said magnification
lens is located at a predetermined position on the wide-angle side,
and the lens is located within the predetermined range on the
closest distance side.
15. The apparatus according to claim 12, wherein a film adapter for
holding a subject such as a film can be detachably attached to a
predetermined position of a front portion of said image sensing
optical system, and film image sensing is allowed in the still
image sensing mode by attaching said film adapter.
16. An image sensing apparatus comprising: an image sensing
apparatus comprising an image sensing optical system which changes
a position of a lens in correspondence with a subject distance;
position detection means for detecting the position of the lens;
image sensing means for outputting an image signal by
photoelectrically converting an optical image of a subject imaged
via said image sensing optical system; signal processing means for
generating a video signal on the basis of the image signal, said
signal processing means comprising first luminance component
generation means for generating a luminance component of the video
signal in accordance with a luminance component of the first image
signal, first chrominance component generation means for generating
chrominance components of the video signal in accordance with
chrominance components of the first image signal, second luminance
component generation means for generating a luminance component of
the video signal by reversing light and dark portions in accordance
with a luminance level of the first image signal, and second
chrominance component generation means for generating chrominance
components of the video signal in accordance with chrominance
components of the first image signal using a predetermined
conversion scheme; and control means which can select one of a
moving image sensing mode for sensing an image of a normal subject
and a film image sensing mode which allows to sense a film image,
and switches an image sensing mode to the film image sensing mode
when the lens is located at a predetermined position, and the video
signal is generated using output signals from said second luminance
component generation means and second chrominance component
generation means.
17. The apparatus according to claim 16, wherein the video signal
generated using the output signals from said second luminance
component generation means and second chrominance component
generation means is a negative-to-positive reversed video signal,
and the film image sensing mode is set to convert a negative film
image into a positive image, and to output the positive image.
18. The apparatus according to claim 16, wherein a film adapter for
holding a subject such as a film can be detachably attached to a
predetermined position of a front portion of said image sensing
optical system, and the film image sensing mode is enabled by
attaching said film adapter.
19. The apparatus according to claim 16, wherein said image sensing
optical system comprises a magnification lens, and said control
means sets the film image sensing mode when said magnification lens
is located at a predetermined position on the wide-angle side, and
the lens is located within a predetermined range on the closest
distance side.
20. An image sensing apparatus which can select one of a moving
image sensing mode and still image sensing mode, and can sense an
image of a close subject such as a film, comprising: image sensing
means for outputting a first image signal by photoelectrically
converting a subject image formed via an image sensing optical
system; and control means for switching an image sensing mode to
the still image sensing mode in accordance with user operation for
sensing an image of the close subject such as the film.
21. An image sensing apparatus comprising: image sensing means for
outputting a sensed image signal by photoelectrically converting a
subject image formed via an image sensing optical system; and
signal processing means for generating a video signal by performing
predetermined processing of the sensed image signal, wherein said
signal processing means comprises: first luminance component
generation means for generating a luminance component of the video
signal in accordance with a luminance level of the sensed image
signal; first chrominance component generation means for generating
chrominance components of the video signal in accordance with
chrominance components of the sensed image signal; second luminance
component generation means for generating a luminance component of
the video signal by reversing light and dark portions in accordance
with the luminance level of the sensed image signal; second
chrominance component generation means for generating chrominance
components of the video signal in accordance with the chrominance
components of the sensed image signal using a predetermined
conversion scheme; color identification means for identifying a
color of the subject on the basis of information associated with a
color in the sensed image signal; and selection means for selecting
said first luminance component generation means and chrominance
component generation means, or said second luminance component
generation means and chrominance component generation means, that
are to be used upon generating and outputting a video signal, in
accordance with an identification result of said color
identification means.
22. An image sensing apparatus comprising: image sensing means for
outputting a sensed image signal by photoelectrically converting a
subject image formed via an image sensing optical system; and
signal processing means for generating a video signal by performing
predetermined processing of the sensed image signal, wherein said
signal processing means comprises: first luminance component
generation means for generating a luminance component of the video
signal in accordance with a luminance level of the sensed image
signal; first chrominance component generation means for generating
chrominance components of the video signal in accordance with
chrominance components of the sensed image signal; second luminance
component generation means for generating a luminance component of
the video signal by reversing light and dark portions in accordance
with the luminance level of the sensed image signal; second
chrominance component generation means for generating chrominance
components of the video signal in accordance with the chrominance
components of the sensed image signal using a predetermined
conversion scheme; color identification means for identifying a
color of the subject on the basis of information associated with a
color in the sensed image signal; first selection means for
selecting said first luminance component generation means and
chrominance component generation means, or said second luminance
component generation means and chrominance component generation
means, that are to be used upon generating and outputting a video
signal, in accordance with an identification result of said color
identification means; and second selection means for inhibiting an
operation of said first selection means.
23. The apparatus according to claim 22, further comprising: third
selection means for, when said second selection means inhibits
operation of said first selection means, selecting said first
luminance component generation means and chrominance component
generation means, or said second luminance component generation
means and chrominance component generation means, that are to be
used upon generating and outputting a video signal, independently
of said first selection means.
24. The apparatus according to claim 21, further comprising: white
balance adjustment means for generating color difference signals
based on outputs from said first luminance component generation
means and said first chrominance component generation means, and
adjusting white balance by controlling gains of the color
difference signals.
25. The apparatus according to claim 21, wherein said second
luminance component generation means and said second chrominance
component generation means output a negative-to-positive reversed
video signal.
26. The apparatus according to claim 21, further comprising: an
image sensing optical system; and a film image sensing adapter for
holding a film at a predetermined position on a front surface of
said image sensing optical system.
27. The apparatus according to claim 21, wherein said color
identification means determines a negative film on the basis of
color difference signals generated based on the sensed image
signal.
28. The apparatus according to claim 21, wherein said color
identification means determines a negative film on the basis of R,
G, and B signals generated based on the sensed image signal.
29. The apparatus according to claim 21, wherein said color
identification means determines a negative film on the basis of
outputs from said first luminance component generation means and
first chrominance component generation means.
30. The apparatus according to claim 21, wherein said color
identification means determines a negative film on the basis of
outputs from said second luminance component generation means and
second chrominance component generation means.
31. An image sensing apparatus, which can select one of a moving
image sensing mode and still image sensing mode, comprising: image
sensing means for outputting a sensed image signal by
photoelectrically converting a subject image formed via an image
sensing optical system; first luminance component generation means
for generating a luminance signal component on the basis of the
sensed image signal; first chrominance component generation means
for generating chrominance signal components on the basis of the
sensed image signal; second luminance component generation means
for generating a luminance component by reversing light and dark
portions in correspondence with a luminance level of the sensed
image signal; second chrominance component generation means for
generating chrominance components in accordance with chrominance
components of the sensed image signal using a predetermined
conversion scheme; and control means which can select one of the
moving image sensing mode and the still image sensing mode, and
selects the still image sensing mode when a video signal is
generated using output signals from said second luminance component
generation means and second chrominance component generation
means.
32. The apparatus according to claim 31, further comprising: color
identification means for identifying a color of the subject in
accordance with the chrominance component in the sensed image
signal, and wherein said control means selects said first luminance
component generation means and first chrominance component
generation means or said second luminance component generation
means and second chrominance component generation means, that are
to be used upon generating the video signal, in accordance with an
output from said color identification means, and selects the still
image sensing mode when the video signal is generated using the
output signals from said second luminance component generation
means and second chrominance component generation means.
33. The apparatus according to claim 31, further comprising: an
image sensing optical system which changes a position of a lens in
correspondence with a subject distance; and position detection
means for detecting the position of the lens, and wherein said
control means forcibly selects the still image sensing mode when
said position detection means detects that the lens is located at a
predetermined position, and the video signal is to be generated
using output signals from said second luminance component
generation means and second chrominance component generation
means.
34. An image sensing apparatus comprising: image sensing means for
outputting a sensed image signal by photoelectrically converting an
optical image formed via an image sensing optical system; first
luminance component generation means for generating a luminance
component of a video signal in accordance with a luminance level of
the sensed image signal; first chrominance component generation
means for generating chrominance components of the video signal in
accordance with chrominance components of the sensed image signal;
second luminance component generation means for generating a
luminance component of the video signal by reversing light and dark
portions in accordance with a luminance level of the sensed image
signal; second chrominance component generation means for
generating chrominance components of the video signal in accordance
with chrominance components of the sensed image signal using a
predetermined conversion scheme; and control means which can select
one of a still image single shot mode for sensing a single still
image, and a still image sequential shot mode for sequentially
sensing the still images, and inhibits the still image sequential
shot mode when the video signal is generated using output signals
from said second luminance component generation means and second
chrominance component generation means.
35. The apparatus according to claim 34, further comprising: color
identification means for identifying a color of the subject in
accordance with the chrominance component in the sensed image
signal, and wherein said control means selects said first luminance
component generation means and first chrominance component
generation means or said second luminance component generation
means and second chrominance component generation means, that are
to be used upon generating the video signal, in accordance with an
output from said color identification means, and selects the still
image single shot mode and inhibits selection of the still image
sequential shot mode when the video signal is generated using the
output signals from said second luminance component generation
means and second chrominance component generation means.
36. The apparatus according to claim 34, further comprising: an
image sensing optical system which changes a position of a lens in
correspondence with a subject distance; and position detection
means for detecting the position of the lens, and wherein said
control means forcibly selects the still image single shot mode and
inhibits selection of the still image sequential mode when said
position detection means detects that the lens is located at a
predetermined position, and the video signal is to be generated
using output signals from said second luminance component
generation means and second chrominance component generation
means.
37. An image sensing apparatus comprising: image sensing means for
outputting a sensed image signal by photoelectrically converting an
optical image formed via an image sensing optical system;
negative/positive reversing means for reversing a negative image to
a positive image by performing predetermined processing of
luminance and chrominance signals; and control means which can
select one of a still image single shot mode for sensing a single
still image, and a still image sequential shot mode for
sequentially sensing the still images, and inhibits the still image
sequential shot mode upon operation of said negative/positive
reversing means.
38. The apparatus according to claim 37, further comprising: color
identification means for detecting based on chrominance components
in the sensed image signal if a negative film is subjected to image
sensing, and wherein said control means enables said
negative/positive reversing means to perform negative/positive
reversing, selects the still image single shot mode, and inhibits
selection of the still image sequential shot mode when said color
identification means detects that the negative film is subjected to
image sensing.
39. The apparatus according to claim 38, further comprising: an
image sensing optical system which changes a position of a lens in
correspondence with a subject distance; and position detection
means for detecting the position of the lens, and wherein said
control means enables said negative/positive reversing means to
perform negative/positive reversing, selects the still image single
shot mode, and inhibits selection of the still image sequential
shot mode when said position detection means detects that the lens
is located at a predetermined position, and said color
identification means detects that the negative film is subjected to
image sensing.
40. An image sensing apparatus which has a normal image sensing
mode and a film image sensing mode for sensing an image on a film
or the like, comprising: image sensing means; exposure control
means for making exposure control by extracting a predetermined
signal component from a sensed image signal output from said image
sensing means; and control means for changing response
characteristics of said exposure control means in correspondence
with the normal image sensing mode and the film image sensing
mode.
41. The apparatus according to claim 40, wherein the predetermined
signal component is a luminance signal level, said exposure control
means comprises an integrator for integrating the luminance signal
level during a predetermined period, and said control means sets a
large integral time constant of said integrator when the film image
sensing mode is selected.
42. An image sensing apparatus comprising: film image sensing mode
selection means for notifying a film image sensing mode; and signal
processing system switching means for switching a setup state of a
signal processing system to a setup state for film image sensing in
the film image sensing mode, wherein when said film image sensing
mode selection means detects the film image sensing mode, said
signal processing system switching means switches the setup state
of the signal processing system to the setup state for film image
sensing, thereby switching a reference voltage of an A/D converter
for A/D-converting a sensed image signal to different voltages in
correspondence with the film image sensing mode and a normal image
sensing mode to improve an S/N ratio in the film image sensing
mode.
43. The apparatus according to claim 42, wherein a top-side
reference voltage of said A/D converter is set to narrow a dynamic
range in the film image sensing mode than in the normal image
sensing mode.
44. The apparatus according to claim 42, wherein said film image
sensing mode selection means comprises means for detecting
switching between the film image sensing mode and normal image
sensing mode.
45. An image sensing apparatus, which has a function of sensing an
image on a photographic film, comprising: detection means for
detecting attachment of an adapter used for sensing an image on the
photographic film; and a noise reduction circuit, wherein a noise
reduction amount of said noise reduction circuit is switched in
synchronism with the attachment of the adapter detected by said
detection means.
46. The apparatus according to claim 45, wherein said noise
reduction circuit has a field memory or frame memory, and executes
field or frame correlation noise reduction.
47. The apparatus according to claim 45, wherein said noise
reduction circuit has a line memory, and executes line correlation
noise reduction.
48. An image sensing apparatus having a function of sensing a
photographic film, comprising: a reversing circuit for reversing a
negative image on the photographic film to a positive image; and a
noise reduction circuit, wherein a noise reduction amount of said
noise reduction circuit is switched in synchronism with reversing
by said reversing circuit.
49. The apparatus according to claim 48, wherein said noise
reduction circuit has a field memory or frame memory, and executes
field or frame correlation noise reduction.
50. The apparatus according to claim 48, wherein said noise
reduction circuit has a line memory, and executes line correlation
noise reduction.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an image sensing apparatus
represented by a video camera and, more particularly, to an image
sensing apparatus having a function of reading an image from a
negative film, a slide film, or the like.
[0002] Along with rapid improvements of the techniques of personal
computers and their peripheral devices, for example, it has now
become easy for an operator to capture and edit a taken picture on
a memory in a personal computer, and to create a unique postcard or
poster. Under this circumstance, the market demand in this
technical field is increasing year by year.
[0003] When an image on a picture is input into a personal
computer, image information on the picture must be converted into
an electrical signal using a video camera or an electronic still
video camera. Since pictures on photographic paper sheets have
various sizes, it is troublesome for an operator to set the field
angle and to determine how to illuminate each picture upon taking
the picture using such camera. Also, a large-scale, dedicated image
sensing apparatus such as a fixing base of a video camera, or the
like is required.
[0004] To solve such problems, an adapter for mounting a negative
(or positive) film is attached to an image sensing lens of the
video camera, and an image projected via the adapter is sensed by
the video camera. The sensed image is converted into a video
signal, which is recorded on a magnetic tape or a memory in a
personal computer, or is output to a monitor. This adapter is
called a "film adapter" (this specification uses this name) or
"film carrier holder", and a camera system with this adapter is
called a photo video camera system or the like.
[0005] The film adapter is merely attached to the lens of a camera,
and has only a function of allowing the user to mount a film. For
this reason, when the film adapter is used, various setup processes
are required. For example, image signal processing inside the
camera must be switched in correspondence with a negative or
positive image. If this setup process is ignored, a negative image
is directly displayed on a monitor. Also, the frame of a film must
be positioned accurately. If this setup process is neglected, an
image on a film frame, which is moving in the adapter, or an image
on a frame which is not set at a predetermined position, is
displayed.
[0006] Hence, when the film adapter is attached to the conventional
video camera and images on a negative film are taken as still
images, various switch operations for attaining the above-mentioned
setup processes (to be referred to as a "film image sensing mode"
hereinafter) are required, resulting in meticulous operations.
[0007] However, when a switch for detecting attachment of the
adapter is arranged on the video camera main body, the number of
parts increases and results in a large camera size and high cost,
the video camera main body must be drastically modified, and so on.
Such problems are the first problems in the conventional camera
attached with the film adapter.
[0008] On the other hand, some conventional cameras that can set
the film image sensing mode often have two modes, i.e., "sequential
shot mode" and "single shot mode". With these cameras, the
photographer selects one of such image sensing modes in
correspondence with his or her purpose at that time. The sequential
shot mode has as its principal object to avoid a loss of an image
sensing chance when a moving subject is captured as still images.
When a still image is taken using the film adapter, the film as a
subject completely stands still integrally with the camera, and
identical still images are repetitively taken unless the sequential
shot mode is canceled. That is, the switching function of the
sequential and single shot modes, which function is convenient for
the user, requires extra user operations. Such problem is the
second problem of the prior art.
[0009] Problems posed when the film adapter is attached to the
video camera or the like are not limited to those concerning the
operability mentioned above.
[0010] More specifically, when the film adapter is not attached to
a conventional camera that can mount a film adapter (when the
camera is not in the film image sensing mode), the camera must be
able to optimally take images of a normal subject as a normal video
camera (i.e., the one without any film image sensing function), as
a matter of course. For this reason, the signal processing circuit
of the camera is set to assure a broad dynamic range, which is not
so required in the film image sensing mode. That is, signals input
to the video camera normally have a large level difference (dynamic
range) depending on the subject to be taken, i.e., a film set in
the film adapter or a normal subject. In order to execute normal
video image sensing prior to the film image sensing mode and to
optimally take images of a subject in the normal video image
sensing, the dynamic range of the signal processing circuit of the
video camera is set to cover a very broad range from a subject in a
dark room to a very bright subject such as a seashore under direct
sunlight. On the other hand, in the film image sensing mode using
the film adapter, since illumination light coming from a backlight
serves as a light source, changes in lightness (luminance level) of
a subject (film) are very smaller than those in a normal image
sensing mode (ranging from a bright seashore to a dark room). If
the signal processing circuit is fixedly set in both the film image
sensing mode and normal subject image sensing mode that have a
large dynamic range difference, the performance of the signal
processing circuit cannot be fully used especially in the film
image sensing mode.
[0011] When images on a film are taken using a camera which sets an
A/D converter in this manner, such A/D converter is not suitable
for the film image sensing mode with a narrow input dynamic range,
and the quality of images to be recorded or displayed on the
monitor deteriorates. This is a problem (third problem) arising
from circuit setups.
[0012] Another problem (fourth problem) arising from circuit setups
will be explained below. This problem is posed since the
conventional camera that can mount the film adapter has moving
image-priority circuit setups. The conventional camera that can
mount the film adapter will be explained below with reference to
FIGS. 1 and 2.
[0013] Referring to FIG. 1, reference numeral 2001 denotes a film
adapter; 2002, a film; 2003, an imaging lens; 2004, an image
sensing element for photoelectrically converting incoming light;
2005, a signal processing circuit for generating luminance and
chrominance signals based on signals generated by the image sensing
element 2004; 2006, a reversing circuit for converting a negative
image into a positive image; 2007, a switching circuit for
selecting whether or not that negative/positive reversing is to be
done; 2008, a noise reduction circuit (N.R.) for reducing noise
components in an image signal; and 2009, an encoder circuit for
converting the luminance and chrominance signals into a video
signal.
[0014] The film adapter 2001 has a light source for illuminating
the film 2002. Light transmitted through the film 2002 is imaged on
the image sensing element 2004 via the lens 2003. An optical signal
incident on the image sensing element 2004 is photoelectrically
converted, and the signal processing circuit 2005 generates
luminance and chrominance signals based on the converted signals.
In this case, when the film 2002 to be sensed is a positive film,
the outputs from the signal processing circuit 2005 are directly
input to the noise reduction circuit 2008 by the switching circuit
2007. On the other hand, when the film 2002 is a negative film, the
outputs from the signal processing circuit 2005 are converted into
those for a positive image by the reversing circuit 2006, and the
converted signals are input to the noise reduction circuit
2008.
[0015] FIG. 2 is a block diagram showing the arrangement of the
frame correlation noise reduction circuit 2008. In FIG. 2,
reference numeral 2031 denotes a frame memory for storing an image
signal for at least one frame; 2032 and 2033, multipliers for
multiplying a signal by coefficients; and 2034 and 2035, adders for
adding signals.
[0016] In the circuit shown in FIG. 2, let (S.sub.in).sub.n be the
signal input of the n-th frame, (S.sub.out).sub.n be the signal
output of the n-th frame, and (S.sub.out).sub.n-1 be the signal
output of the (n-1)-th frame from the frame memory 2031. As shown
in equation (1) below, the output (S.sub.out).sub.n is obtained by
adding the product of the input (S.sub.in).sub.n and a coefficient
k and the product of the output (S.sub.out).sub.n-1 and a
coefficient (1-k):
(S.sub.out).sub.n=k.multidot.(S.sub.in).sub.n+(1-k).multidot.(S.sub.out).s-
ub.n-1(0<k.ltoreq.1) (1)
[0017] Noise components produced between the (n-1)-th and n-th
frames are reduced by multiplication by the coefficient (1-k).
[0018] The image signal in which noise components are reduced by
the noise reduction circuit 2008 is converted into a standard
television (TV) signal by the encoder circuit 2009.
[0019] However, in the conventional image sensing apparatus shown
in FIG. 1, a small coefficient k must be set in the noise reduction
circuit to improve the noise reduction effect. However, when a
subject that moves fast is sensed, the resolution lowers as the
coefficient k decreases. Since the video camera is normally used
for sensing a moving subject, the coefficient k must be set at a
numerical value close to 1 in consideration of the resolution. As a
result, since the noise reduction effect is impaired, noise
components become conspicuous when a still subject such as a film
or the like is sensed via the film adapter. This is the fourth
problem.
SUMMARY OF THE INVENTION
[0020] As described above, the conventional image sensing apparatus
that can mount the film adapter has room for improvement in
automatic detection of attachment of the adapter.
[0021] Furthermore, if attachment of the adapter can be detected,
there is room for improvement in automatically setting the image
sensing apparatus in an optimal image sensing condition when the
film adapter is attached.
[0022] It is an object of the present invention to provide an image
sensing apparatus which automatically selects a film image sensing
mode when a film adapter is attached, can remove and solve the
above-mentioned drawbacks and problems, has good operability, and
can assure reliable operations.
[0023] In order to achieve the above object, an image sensing
apparatus of the present invention, which has a moving image
sensing mode and a still image sensing mode, and can sense a close
subject, comprises image sensing means for outputting a first image
signal by photoelectrically converting a subject image, detection
means for detecting based on a predetermined signal component in
the first image signal if a subject is close to the apparatus (for
example, processing for determining if a color difference signal
falls within a range 201 to be described later), and control means
for switching the image sensing mode to the still image sensing
mode when the detection means detects that the subject is close to
the apparatus.
[0024] Therefore, when a negative film is subjected to image
sensing using a video camera, a negative/positive reversing
function of the video camera can be automatically enabled, and the
video camera can be automatically set in the still image sensing
mode, thus eliminating cumbersome operations and avoiding
unnecessary scenes from being sensed in the moving image sensing
mode due to operation errors.
[0025] According to one preferred aspect of the present invention,
the detection means detects based on chrominance signal components
in the first image signal if the subject is a negative film.
Whether or not the subject is a negative film is detected based on
chrominance signal components in a sensed image signal, and when a
negative film is detected, luminance and chrominance signal
components are converted into those for a positive image, and the
converted signal components are output. In case of a video camera,
a characteristic color difference vector of a negative film is
detected using a white balance circuit as a technique unique to
video cameras so as to automatically set the apparatus in the film
image sensing mode and to automatically enable the
negative/positive reversing function. Hence, the operator is
relieved from any troublesome operations for manually setting the
apparatus in the positive/negative reversing mode and the still
image sensing mode, and any probability of operation errors.
[0026] According to one preferred aspect of the present invention,
the apparatus comprises first luminance component generation means
(corresponding to a YC signal generation circuit 502 in
embodiments) for generating a luminance component based on the
first image signal, first chrominance component generation means
(corresponding to color difference generation circuits 505 and 1101
in the embodiments) for generating chrominance components based on
the first image signal, second luminance component generation means
(corresponding to a negative/positive reversing circuit 513 in the
embodiments) for generating a luminance component by reversing
light and dark portions in correspondence with a luminance level of
the first image signal, and second chrominance component generation
means (corresponding to the negative/positive reversing circuit 513
in the embodiments) for generating chrominance components in
accordance with the chrominance components of the first image
signal using a predetermined conversion scheme, and when the
detection means detects that the subject is not a negative film,
the control means controls to generate an image signal using output
signals from the first luminance component generation means and
first chrominance component generation means, and when the
detection means detects that the subject is a negative film, the
control means controls to generate an image signal using output
signals from the second luminance component generation means and
second chrominance component generation means (corresponding to
processing for selecting one of a film image sensing mode and
moving image sensing mode depending on whether or not a color
difference signal falls within the range 201 in FIG. 12 in the
processing of the flow chart shown in FIG. 13).
[0027] According to one preferred aspect of the present invention,
a film adapter for holding a subject such as a film can be
detachably attached to a predetermined position of a front portion
of an image sensing optical system, and the film image sensing mode
is enabled by attaching the film adapter. Therefore, since the film
image sensing mode is enabled by attaching the film adapter, film
image sensing can be easily done by a normal video camera without
specially modifying the camera itself.
[0028] It is another object of the present invention to provide an
image sensing apparatus comprising image sensing means for
outputting a first image signal by photoelectrically converting an
optical image formed via an image sensing optical system, signal
processing means (corresponding to a camera signal processing
circuit 409 in an embodiment) for generating an image signal by
performing predetermined processing of the first image signal, and
film image sensing means for sensing a film image by mounting a
film image sensing adapter, the signal processing means comprising
first luminance component generation means (corresponding to a YC
signal generation circuit 502 in the embodiments) for generating a
luminance component of the image signal in accordance with a
luminance level of the first image signal, first chrominance
component generation means (corresponding to the color difference
generation circuits 505 and 1101 in the embodiments) for generating
chrominance components of the image signal in accordance with
chrominance components of the first image signal, second luminance
component generation means (corresponding to a negative/positive
reversing circuit 513 in the embodiments) for generating a
luminance component of the image signal by reversing light and dark
portions in accordance with a luminance level of the first image
signal, second chrominance component generation means
(corresponding to the negative/positive reversing circuit 513 in
the embodiments) for generating chrominance components of the image
signal in accordance with chrominance components of the first image
signal using a predetermined conversion scheme, and control means
(corresponding to processing in the flow chart of FIG. 13 by a
camera control circuit 105) which can select one of a moving image
sensing mode for sensing a moving image, and a film image sensing
mode for sensing a photographic film image using the film image
sensing means, and selects the film image sensing mode when an
image signal is generated using output signals from the second
luminance component generation means and second chrominance
component generation means. Hence, when a video camera senses a
negative film as a still image using a film adapter or the like,
the video camera can be automatically set in the still image
sensing mode upon enabling the negative/positive reversing function
of the video camera. In this manner, the operator is relieved of
any troublesome operations for manually setting the apparatus in
the positive/negative reversing mode and the still image sensing
mode, and can avoid unnecessary scenes from being sensed in the
moving image mode set as a result of operation errors.
[0029] According to one preferred aspect of the present invention,
the apparatus comprises color identification means (corresponding
to processing executed by the camera control circuit 105 in the
embodiments) for identifying a color of the subject on the basis of
information associated with a color of the first image signal, and
the control means selects on the basis of an identification result
of the color identification means whether the image signal is
generated by the first luminance component generation means and
first chrominance component generation means, or by the second
luminance component generation means and second chrominance
component generation means, and selects the film image sensing mode
upon selecting image signal generation using the second luminance
component generation means and second chrominance component
generation means. Hence, the characteristic color difference vector
of a negative film is detected using a white balance circuit as a
technique unique to video cameras, so that the apparatus can be
automatically set in the film image sensing mode, and can
automatically enable the negative/positive reversing function. In
this manner, the operator can be relieved of any burdensome
operations for setting the apparatus in the still image sensing
mode after he or she sets the negative/positive reversing mode, and
any probability of operation errors.
[0030] According to one preferred aspect of the present invention,
the second luminance component generation means and second
chrominance component generation means output a
negative-to-positive reversed image signal.
[0031] It is still another object of the present invention to
provide an image sensing apparatus comprising an image sensing
optical system (corresponding to an inner focus lens shown in FIG.
6) which changes a position of a lens in correspondence with a
subject distance, position detection means (corresponding to
processing for counting driving pulses to be supplied to a
magnification lens driver 413 and focus-compensation lens driver
415 in a lens/camera control circuit 418 shown in FIG. 5 in an
embodiment) for detecting the position of the lens, image sensing
means (corresponding to an image sensing element 407 in the
embodiments) for outputting a first image signal by
photoelectrically converting an optical image of a subject imaged
via the image sensing optical system, and control means (mainly
corresponding to processing in the flow chart of FIG. 14 by a
camera control circuit 105 in the embodiments) which can select one
of a plurality of image sensing modes including a moving image
sensing mode for sensing a moving image and a film image sensing
mode for sensing a close subject such as a film, and sets an image
sensing mode in the film image sensing mode when the lens is
located at a predetermined position. Hence, since the film image
sensing mode is set in correspondence with the lens position, the
film image sensing state using the film adapter can be accurately
detected by detecting a specific lens position obtained from a
closest distance in-focus condition of an image sensing lens. In
this manner, the above-mentioned drawbacks can be removed and
demerits of the prior art can be compensated for while preventing
operation errors of the apparatus.
[0032] According to one preferred aspect of the present invention,
the control means sets the film image sensing mode when the lens is
located within a predetermined range on the closest distance
side.
[0033] According to one preferred aspect of the present invention,
the image sensing optical system comprises a magnification lens,
and the control means (mainly corresponding to the camera control
circuit 105 in the embodiments) sets the film image sensing mode
when the magnification lens is located at a predetermined position
on the wide-angle side, and the lens is located within a
predetermined range on the closest distance side.
[0034] According to one preferred aspect of the present invention,
a film adapter for holding a subject such as a film can be
detachably attached to a predetermined position of a front portion
of the image sensing optical system, and the film image sensing
mode is enabled by attaching the film adapter. Therefore, since the
film image sensing mode is enabled by attaching the film adapter,
film image sensing can be easily done by a normal video camera
without specially modifying the camera itself.
[0035] It is still another object of the present invention to
provide an image sensing apparatus comprising an image sensing
optical system (corresponding to an inner focus lens shown in FIG.
6) which changes a position of a lens in correspondence with a
subject distance, position detection means (corresponding to
processing for counting driving pulses to be supplied to a
magnification lens driver 413 and focus-compensation lens driver
415 in a lens/camera control circuit 418 shown in FIG. 5 in an
embodiment) for detecting the position of the lens, image sensing
means (corresponding to an image sensing element 407 in the
embodiments) for outputting a first image signal by
photoelectrically converting an optical image of a subject imaged
via the image sensing optical system, and control means (mainly
corresponding to processing in the flow chart of FIG. 14 by a
camera control circuit 105 in the embodiments) which can select one
of a plurality of image sensing modes including a moving image
sensing mode for sensing a moving image and a still image sensing
mode for sensing a still image, and sets an image sensing mode in
the still image sensing mode when the lens is located at a
predetermined position (corresponding to a region 904 in FIG. 7 in
the embodiments). More specifically, since the still image sensing
mode is set depending on the lens position, the still image sensing
mode that assumes film image sensing can be set detecting a
specific lens position obtained from a closest distance in-focus
condition of an image sensing lens. Thus, the above-mentioned
drawbacks can be removed and demerits of the prior art can be
compensated for while accurately detecting the film image sensing
state and preventing operation errors of the apparatus.
[0036] According to one preferred aspect of the present invention,
the control means sets the still image sensing mode when the lens
is located with a predetermined range on the closest distance side
(corresponding to the region 904 in FIG. 7 in the embodiments).
[0037] According to one preferred aspect of the present invention,
the image sensing optical system comprises a magnification lens,
and the control means sets the still image sensing mode when the
magnification lens is located at a predetermined position on the
wide-angle side (corresponding to a region 904 in FIG. 7 in the
embodiments), and the lens is located within the predetermined
range on the closest distance side.
[0038] According to one preferred aspect of the present invention,
a film adapter (corresponding to a film adapter 3 in the
embodiments) for holding a subject such as a film can be detachably
attached to a predetermined position of a front portion of the
image sensing optical system, and film image sensing is allowed in
the still image sensing mode by attaching the film adapter.
Therefore, since film image sensing is allowed by attaching the
film adapter, film image sensing can be easily done by a normal
video camera without specially modifying the camera itself.
[0039] It is still another object of the present invention to
provide an image sensing apparatus comprising an image sensing
optical system (corresponding to an inner focus lens shown in FIG.
6) which changes a position of a lens in correspondence with a
subject distance, position detection means (corresponding to
processing for counting driving pulses to be supplied to a
magnification lens driver 413 and focus-compensation lens driver
415 in a lens/camera control circuit 418 shown in FIG. 5 in an
embodiment) for detecting the position of the lens, image sensing
means for outputting a first image signal by photoelectrically
converting an optical image of a subject imaged via the image
sensing optical system, signal processing means (corresponding to a
camera signal processing circuit 409 in the embodiments) for
generating an image signal on the basis of the first image signal,
the signal processing means comprising first luminance component
generation means (corresponding to a YC signal generation circuit
502 in the embodiments) for generating a luminance component of the
image signal in accordance with a luminance component of the first
image signal, first chrominance component generation means
(corresponding to the color difference generation circuits 505 and
1101 in the embodiments) for generating chrominance components of
the image signal in accordance with chrominance components of the
first image signal, second luminance component generation means
(corresponding to a negative/positive reversing circuit 513 in the
embodiments) for generating a luminance component of the image
signal by reversing light and dark portions in accordance with a
luminance level of the first image signal, and second chrominance
component generation means (corresponding to the negative/positive
reversing circuit 513 in the embodiments) for generating
chrominance components of the image signal in accordance with
chrominance components of the first image signal using a
predetermined conversion scheme, and control means (corresponding
to processing in the flow chart of FIG. 15 by a camera control
circuit 105 in the embodiments) which can select one of a moving
image sensing mode for sensing an image of a normal subject and a
film image sensing mode which allows to sense a film image, and
switches an image sensing mode to the film image sensing mode when
the lens is located at a predetermined position, and an image
signal is generated using output signals from the second luminance
component generation means and second chrominance component
generation means. More specifically, since the image sensing mode
is switched to the film image sensing mode in correspondence with
the lens position, the film image sensing mode that assumes film
image sensing can be set by detecting a specific lens position
obtained from the closest distance in-focus condition of an image
sensing lens. Thus, the above-mentioned drawbacks can be removed
and demerits of the prior art can be compensated for while
accurately detecting the film image sensing state and preventing
operation errors of the apparatus. Since the specific position
obtained from the closest distance in-focus condition of an image
sensing lens is detected as well as the characteristic color
difference vector of a negative film, the above-mentioned drawbacks
can be removed and demerits of the prior art can be compensated for
while accurately detecting the negative film image sensing state
and preventing operation errors of the apparatus.
[0040] According to one preferred aspect of the present invention,
the image signal generated using the output signals from the second
luminance component generation means and second chrominance
component generation means is a negative-to-positive reversed image
signal, and the film image sensing mode is set to convert an image
on a negative film into a positive image, and to output the
positive image.
[0041] According to one preferred aspect of the present invention,
a film adapter (corresponding to a film adapter 3 in the
embodiments) for holding a subject such as a film can be detachably
attached to a predetermined position of a front portion of the
image sensing optical system, and the film image sensing mode is
allowed by attaching the film adapter. Therefore, since film image
sensing is allowed by attaching the film adapter, film image
sensing can be easily done by a normal video camera without
specially modifying the camera itself.
[0042] According to one preferred aspect of the present invention,
the image sensing optical system comprises a magnification lens,
and the control means sets the film image sensing mode when the
magnification lens is located at a predetermined position on the
wide-angle side, and the lens is located within a predetermined
range on the closest distance side. Hence, when the magnification
lens is located at the predetermined position on the wide-angle
side and the lens is located within the predetermined range on the
closest distance side, the film image sensing mode is set, thus
realizing a system which utilizes the characteristics of the inner
focus lens and has good operability.
[0043] It is still another object of the present invention to
provide an image sensing apparatus which can select one of a moving
image sensing mode and still image sensing mode, and can sense an
image of a close subject such as a film, comprising image sensing
means (corresponding to an image sensing element 407 in an
embodiment) for outputting a first image signal by
photoelectrically converting a subject image formed via an image
sensing optical system, and control means (corresponding to
processing in the flow chart of FIG. 16 by a camera control circuit
105 in the embodiments) for switching an image sensing mode to the
still image sensing mode in accordance with user operation for
sensing an image of the close subject such as the film.
[0044] Accordingly, since the image sensing mode is switched to the
still image sensing mode in accordance with user operation for film
image sensing, when a negative film image is sensed as a still
image using a video camera, the video camera can be automatically
set in the still image sensing mode by enabling, e.g., a
negative/positive reversing function of the video camera. Hence,
cumbersome operations can be alleviated, and unnecessary scenes can
be prevented from being sensed in the moving image mode set due to
operation errors.
[0045] It is still another object of the present invention to
provide an image sensing apparatus comprising image sensing means
(corresponding to an image sensing element 407 in an embodiment)
for outputting a sensed image signal by photoelectrically
converting a subject image formed via an image sensing optical
system, and signal processing means (corresponding to a camera
signal processing circuit in the embodiments) for generating a
video signal by performing predetermined processing of the sensed
image signal, the signal processing means comprising first
luminance component generation means (corresponding to a YC signal
generation circuit 502 or 1103 in an embodiment) for generating a
luminance component of the video signal in accordance with a
luminance level of the sensed image signal, first chrominance
component generation means (corresponding to a color difference
signal generation circuit 505 or 1101 in the embodiments) for
generating chrominance components of the video signal in accordance
with chrominance components of the sensed image signal, second
luminance component generation means (corresponding to a
negative/positive reversing circuit 512 or 1601 in the embodiments)
for generating a luminance component of the video signal by
reversing light and dark portions in accordance with the luminance
level of the sensed image signal, second chrominance component
generation means (corresponding to the negative/positive reversing
circuit 512 or 1601 in the embodiments) for generating chrominance
components of the video signal in accordance with the chrominance
components of the sensed image signal using a predetermined
conversion scheme, color identification means for identifying a
color of the subject on the basis of information associated with a
color in the sensed image signal, and selection means
(corresponding to a camera control circuit 105, 902, 1102, 120, or
1401 in the embodiments) for selecting the first luminance
component generation means and chrominance component generation
means, or the second luminance component generation means and
chrominance component generation means, that are to be used upon
generating and outputting a video signal, in accordance with an
identification result of the color identification means.
[0046] Hence, signal processing optimal to the state of the subject
to be sensed can be automatically done in accordance with signal
components in the sensed image signal.
[0047] It is still another object of the present invention to
provide an image sensing apparatus comprising image sensing means
for outputting a sensed image signal by photoelectrically
converting a subject image formed via an image sensing optical
system, and signal processing means for generating a video signal
by performing predetermined processing of the sensed image signal,
the signal processing means comprising first luminance component
generation means for generating a luminance component of the video
signal in accordance with a luminance level of the sensed image
signal, first chrominance component generation means for generating
chrominance components of the video signal in accordance with
chrominance components of the sensed image signal, second luminance
component generation means for generating a luminance component of
the video signal by reversing light and dark portions in accordance
with the luminance level of the sensed image signal, second
chrominance component generation means for generating chrominance
components of the video signal in accordance with the chrominance
components of the sensed image signal using a predetermined
conversion scheme, color identification means for identifying a
color of the subject on the basis of information associated with a
color in the sensed image signal, first selection means for
selecting the first luminance component generation means and
chrominance component generation means, or the second luminance
component generation means and chrominance component generation
means, that are to be used upon generating and outputting a video
signal, in accordance with an identification result of the color
identification means, and second selection means (corresponding to
a camera control circuit 902 in an embodiment) for inhibiting
operation of the first selection means. Accordingly, signal
processing optimal to the state of the subject to be sensed can be
automatically done in accordance with signal components in the
sensed image signal, and operation errors of that automatic
selection function can be prevented, thus preferentially reflecting
the photographer's will.
[0048] According to one preferred aspect of the present invention,
the image sensing apparatus comprises third selection means
(corresponding to the camera control circuit 902 in the
embodiments) for, when the second selection means inhibits
operation of the first selection means, selecting the first
luminance component generation means and chrominance component
generation means, or the second luminance component generation
means and chrominance component generation means, that are to be
used upon generating and outputting a video signal, independently
of the first selection means.
[0049] According to one preferred aspect of the present invention,
the image sensing apparatus comprises white balance adjustment
means (corresponding to gain control circuits 503 and 504, and a
camera control circuit 105, 902, 1102, 120, or 1401 in the
embodiments) for generating color difference signals based on
outputs from the first luminance component generation means and the
first chrominance component generation means, and adjusting white
balance by controlling gains of the color difference signals.
Accordingly, negative film image sensing can be automatically
detected, and a negative/positive reversing function is
automatically executed by detecting, e.g., the characteristic color
difference vector of a negative film using a white balance circuit
as a technique unique to the video camera. When a negative film
image is to be sensed using a film adapter or the like, the
operator is free from any cumbersome operations for enabling the
reversing function by operating a switch without arranging any film
adapter mounting detection switch to the video camera. Also, since
the means for disabling the automatic execution function of the
negative/positive reversing function based on negative film
detection is arranged, operation errors of the negative/positive
reversing function caused by detection errors of a negative film,
which tend to take place when a subject having a hue similar to the
negative film is sensed, can be prevented.
[0050] According to one preferred aspect of the present invention,
there is disclosed the image sensing apparatus wherein the second
luminance component generation means and the second chrominance
component generation means output a negative-to-positive reversed
video signal.
[0051] According to one preferred aspect of the present invention,
the image sensing apparatus comprises an image sensing optical
system, and a film image sensing adapter (corresponding to a film
adapter 803 in the embodiments) for holding a film at a
predetermined position on a front surface of the image sensing
optical system. Accordingly, a film image sensing apparatus which
can execute film image sensing by attaching the film image sensing
adapter to the image sensing optical system, can use the existing
camera itself, does not require any bulky arrangement, allows a
size reduction, simple operation, and cost reduction, and has good
operability, can be realized.
[0052] According to one preferred aspect of the present invention,
the color identification means determines a negative film on the
basis of color difference signals generated based on the sensed
image signal. Since a negative film is determined based on the
color difference signals, R, G, and B signals, and the like
generated based on the sensed image signal, selection by the
selection means can be done in correspondence with the circuit
arrangement of the video camera, and the degree of freedom in
design can be increased.
[0053] According to one preferred aspect of the present invention,
the color identification means determines a negative film on the
basis of R, G, and B signals generated based on the sensed image
signal.
[0054] According to one preferred aspect of the present invention,
the color identification means determines a negative film on the
basis of outputs from the first luminance component generation
means and first chrominance component generation means.
[0055] According to one preferred aspect of the present invention,
the color identification means determines a negative film on the
basis of outputs from the second luminance component generation
means and second chrominance component generation means. Hence,
since a negative film can be determined on the basis of signals
either before or after negative/positive reversing, means with
higher reliability can be selected in accordance with situations
and the circuit arrangement of the video camera, thus increasing
the degree of freedom in design, and improving the reliability of
negative film identification.
[0056] It is still another object of the present invention to
provide an image sensing apparatus, which can select one of a
moving image sensing mode and still image sensing mode, comprising
image sensing means (corresponding to an image sensing element 407
in an embodiment) for outputting a sensed image signal by
photoelectrically converting a subject image formed via an image
sensing optical system (corresponding to lenses 402, 403, 405, and
406, and an iris 404 in the embodiments), first luminance component
generation means (corresponding to a YC signal generation circuit
502 in the embodiments) for generating a luminance signal component
on the basis of the sensed image signal, first chrominance
component generation means (corresponding to the color difference
generation circuits 505, 1101 in the embodiments) for generating
chrominance signal components on the basis of the sensed image
signal, second luminance component generation means (corresponding
to a negative/positive reversing circuit 513 in the embodiments)
for generating a luminance component by reversing light and dark
portions in correspondence with a luminance level of the sensed
image signal, second chrominance component generation means
(corresponding to the negative/positive reversing circuit 513 in
the embodiments) for generating chrominance components in
accordance with chrominance components of the sensed image signal
using a predetermined conversion scheme, and control means which
can select one of the moving image sensing mode and the still image
sensing mode, and selects the still image sensing mode when a video
signal is generated using output signals from the second luminance
component generation means and second chrominance component
generation means (corresponding to processing for selecting one of
a film image sensing mode and moving image sensing mode depending
on whether or not a color difference signal falls within a range in
the processing of the flow chart shown in FIG. 3 executed by a
camera control circuit 105 in the embodiments). Hence, the image
sensing mode can be automatically set in correspondence with the
state of the signal processing circuit, thus effectively preventing
operation errors and improving operability.
[0057] For example, when a negative film image is sensed using a
video camera, the video camera can be automatically set in the
still image sensing mode by enabling its negative/positive
reversing function. Hence, complicated operations can be precluded,
and unnecessary scenes can be prevented from being sensed in the
moving image mode set by operation errors.
[0058] According to one preferred aspect of the present invention,
the image sensing apparatus comprises color identification means
(corresponding to processing in steps A302 and A303 in the flow
chart corresponding to the processing executed by the camera
control circuit 105 in the embodiments) for identifying a color of
the subject in accordance with the chrominance component in the
sensed image signal, and the control means selects the first
luminance component generation means and first chrominance
component generation means or the second luminance component
generation means and second chrominance component generation means,
that are to be used upon generating the video signal, in accordance
with an output from the color identification means, and selects the
still image sensing mode when the video signal is generated using
the output signals from the second luminance component generation
means and second chrominance component generation means. As
described above, since the luminance and chrominance signal
processing circuits are automatically switched on the basis of
chrominance signal components in the sensed image signal, for
example, when the subject is a negative film, luminance and
chrominance signal components are converted to those for a positive
image, and the image sensing mode can also be switched to the still
image sensing mode suitable for film image sensing.
[0059] According to one preferred aspect of the present invention,
the image sensing apparatus comprises an image sensing optical
system which changes a position of a lens in correspondence with a
subject distance, and position detection means (corresponding to
processing for counting driving pulses to be supplied to a
magnification lens driver 413 and focus-compensation lens driver
415 in a lens/camera control circuit 418 in the embodiments) for
detecting the position of the lens, and the control means forcibly
selects the still image sensing mode when the position detection
means detects that the lens is located at a predetermined position,
and the video signal is to be generated using output signals from
the second luminance component generation means and second
chrominance component generation means. In this manner, since the
lens position information is used for setting the image sensing
mode, the film image sensing mode (still image sensing mode) can be
automatically set with high precision.
[0060] It is still another object of the present invention to
provide an image sensing apparatus comprising image sensing means
(corresponding to an image sensing element 407 in an embodiment)
for outputting a sensed image signal by photoelectrically
converting an optical image formed via an image sensing optical
system, first luminance component generation means (corresponding
to a YC signal generation circuit 502 in the embodiments) for
generating a luminance component of a video signal in accordance
with a luminance level of the sensed image signal, first
chrominance component generation means (corresponding to the color
difference generation circuits 505, 1101 in the embodiments) for
generating chrominance components of the video signal in accordance
with chrominance components of the sensed image signal, second
luminance component generation means (corresponding to a
negative/positive reversing circuit 513 in the embodiments) for
generating a luminance component of the video signal by reversing
light and dark portions in accordance with a luminance level of the
sensed image signal, second chrominance component generation means
(corresponding to the negative/positive reversing circuit 513 in
the embodiments) for generating chrominance components of the video
signal in accordance with chrominance components of the sensed
image signal using a predetermined conversion scheme, and control
means which can select one of a still image single shot mode for
sensing a single still image, and a still image sequential shot
mode for sequentially sensing the still images, and inhibits the
still image sequential shot mode when the video signal is generated
using output signals from the second luminance component generation
means and second chrominance component generation means
(corresponding to processing in the flow chart shown in FIG. 36 in
the embodiments). In the image sensing apparatus which has a single
shot mode and sequential shot mode in association with still image
sensing, and has a plurality of sets of luminance signal generation
means and chrominance signal generation means, switching and
inhibition of the still image single shot mode and still image
sequential shot mode are automatically controlled in correspondence
with the luminance signal generation means and chrominance signal
generation means to be used at that time. Accordingly, the image
sensing mode can be automatically set in correspondence with the
state of the signal processing circuit, thus effectively preventing
operation errors and improving operability.
[0061] For example, when a negative film image is sensed using a
video camera, the sequential shot mode is inhibited from being set
as the still image sensing mode and the single shot mode can be
automatically set by enabling the negative/positive reversing
function of that video camera. In this way, wasteful operations
such as sequential shots of an identical film image can be
prevented, and the video camera can be automatically set. Hence,
complicated operations can be done away with and unnecessary scenes
can be prevented from being sensed in the moving image mode set by
operation errors.
[0062] According to one preferred aspect of the present invention,
the image sensing apparatus comprises color identification means
(corresponding to processing in steps 1702 and 1703 in the flow
chart shown in FIG. 36 corresponding to the processing executed by
a camera control circuit 105 in the embodiments) for identifying a
color of the subject in accordance with the chrominance component
in the sensed image signal, and the control means selects the first
luminance component generation means and first chrominance
component generation means or the second luminance component
generation means and second chrominance component generation means,
that are to be used upon generating the video signal, in accordance
with an output from the color identification means, and selects the
still image single shot mode and inhibits selection of the still
image sequential shot mode when the video signal is generated using
the output signals from the second luminance component generation
means and second chrominance component generation means. As
described above, since the luminance and chrominance signal
processing circuits are automatically switched on the basis of
chrominance signal components in the sensed image signal, for
example, when the subject is a negative film, luminance and
chrominance signal components are converted to those for a positive
image, and the image sensing mode can also be switched to the still
image single shot mode suitable for film image sensing.
[0063] For example, the characteristic color difference vector of a
negative film is detected using a white balance circuit as a
technique unique to video cameras so as to automatically set the
apparatus in the film image sensing mode and to automatically
enable the negative/positive reversing function. Hence, the
operator is relieved from any troublesome operations for manually
setting the apparatus in the positive/negative reversing mode and
the still image sensing mode, and any probability of operation
errors.
[0064] According to one preferred aspect of the present invention,
the image sensing apparatus comprises an image sensing optical
system (corresponding to lenses 402, 403, 405, and 406, and an iris
404 in the embodiments) which changes a position of a lens in
correspondence with a subject distance, and position detection
means (corresponding to processing for counting driving pulses to
be supplied to a magnification lens driver 413 and
focus-compensation lens driver 415 in a lens/camera control circuit
418 in the embodiments) for detecting the position of the lens, and
the control means forcibly selects the still image single shot mode
and inhibits selection of the still image sequential mode when the
position detection means detects that the lens is located at a
predetermined position, and the video signal is to be generated
using output signals from the second luminance component generation
means and second chrominance component generation means. In this
fashion, since the lens position information is also used for
setting the image sensing mode, the film image sensing mode (still
image single shot mode) can be automatically set with higher
precision.
[0065] It is still another object of the present invention to
provide an image sensing apparatus comprising image sensing means
(corresponding to an image sensing element 407 in an embodiment)
for outputting a sensed image signal by photoelectrically
converting an optical image formed via an image sensing optical
system (corresponding to processing for counting driving pulses to
be supplied to a magnification lens driver 413 and
focus-compensation lens driver 415 in a lens/camera control circuit
418 in the embodiments), negative/positive reversing means
(corresponding to a negative/positive reversing circuit 513 in the
embodiments) for reversing a negative image to a positive image by
performing predetermined processing of luminance and chrominance
signals, and control means which can select one of a still image
single shot mode for sensing a single still image, and a still
image sequential shot mode for sequentially sensing the still
images, and inhibits the still image sequential shot mode upon
operation of the negative/positive reversing means (corresponding
to processing in the flow charts shown in FIGS. 36 and 37 by a
camera control circuit in the embodiments). In this manner, since
selection of the still image sequential shot mode is inhibited upon
negative/positive reversing, the operator is exempt from cumbersome
operations for setting a negative/positive reversing mode and then
switching apparatus to the still image single shot mode, and
possibility of operation errors.
[0066] According to one preferred aspect of the present invention,
the image sensing apparatus comprises color identification means
(corresponding to processing in steps 1702 and 1703 in the flow
chart shown in FIG. 36 corresponding to the processing executed by
a camera control circuit 105 in the embodiments) for detecting
based on chrominance components in the sensed image signal if a
negative film is subjected to image sensing, and the control means
enables the negative/positive reversing means to perform
negative/positive reversing, selects the still image single shot
mode, and inhibits selection of the still image sequential shot
mode when the color identification means detects that the negative
film is subjected to image sensing. In this manner, since it is
automatically detected that the negative film is subjected to image
sensing, operations for performing negative/positive reversing by
enabling the negative/positive reversing means, selecting the still
image single shot mode, and inhibiting selection of the still image
sequential shot mode can be automated.
[0067] According to one preferred aspect of the present invention,
the image sensing apparatus comprises an image sensing optical
system (corresponding to lenses 402, 403, 405, and 406, and an iris
404 in the embodiments) which changes a position of a lens in
correspondence with a subject distance, and position detection
means (corresponding to processing for counting driving pulses to
be supplied to a magnification lens driver 413 and
focus-compensation lens driver 415 in a lens/camera control circuit
418 in the embodiments) for detecting the position of the lens, and
the control means enables the negative/positive reversing means to
perform negative/positive reversing, selects the still image single
shot mode, and inhibits selection of the still image sequential
shot mode when the position detection means detects that the lens
is located at a predetermined position, and the color
identification means detects that the negative film is subjected to
image sensing. In this manner, since the lens position information
is also used for setting the image sensing mode, the film image
sensing mode (still image single shot mode) can be automatically
set with higher precision.
[0068] It is still another object of the present invention to
provide an image sensing apparatus which has a normal image sensing
mode and a film image sensing mode for sensing a film image or the
like, comprising image sensing means (corresponding to an image
sensing element 2006), exposure control means (corresponding to a
gate circuit 2011, an integrator 2012, an exposure control circuit
in a system control circuit 2013, a D/A converter 2016, an iris
driving circuit 2017, an iris motor 2019, an iris 2005, and an iris
encoder 2015 in FIG. 39) for making exposure control by extracting
a predetermined signal component from a sensed image signal output
from the image sensing means, and control means (corresponding to a
reset pulse generator in the system control circuit 2013 in FIG.
39) for changing response characteristics of the exposure control
means in correspondence with the normal image sensing mode and the
film image sensing mode. In this manner, since the response
characteristics of the exposure control means are changed between
the normal image sensing mode and the film image sensing mode, an
optimal image sensing state can be obtained in each image sensing
mode.
[0069] According to one preferred aspect of the present invention,
there is provided the image sensing apparatus wherein the
predetermined signal component is a luminance signal level, the
exposure control means comprises an integrator for integrating the
luminance signal level during a predetermined period, and the
control means sets a large integral time constant of the integrator
when the film image sensing mode is selected. As described above,
since the integrator for integrating the luminance levels during
the predetermined period is arranged as the exposure control means,
and a large integral time constant is set upon selecting the film
image sensing mode, even when the exposure state largely changes
upon feeding the frame of a film, image quality can be prevented
from deteriorating, and the exposure state can be quickly set after
the film frame has moved.
[0070] It is still another object of the present invention to
provide an image sensing apparatus comprising film image sensing
mode selection means for notifying a film image sensing mode, and
signal processing system switching means for switching a setup
state of a signal processing system to a setup state for film image
sensing in the film image sensing mode, wherein when the film image
sensing mode selection means detects the film image sensing mode,
the signal processing system switching means switches the setup
state of the signal processing system to the setup state for film
image sensing, thereby switching a reference voltage of an A/D
converter for A/D-converting a sensed image signal to different
voltages in correspondence with the film image sensing mode and a
normal image sensing mode to improve an S/N ratio in the film image
sensing mode.
[0071] With this arrangement, since the signal processing system
switching means switches the signal processing system to the setup
state for the film image sensing mode in the film image sensing
mode, the S/N ratio of an image signal obtained by sensing a film
can be improved. Furthermore, with this arrangement, in the film
image sensing mode, the top-side reference voltage of the A/D
converter can be switched to a voltage optimal to film image
sensing. Moreover, the S/N ratio in the film image sensing mode for
a negative film, positive film, and the like can be improved
without any influences on image quality in the normal image sensing
mode, and a higher-quality image can be provided.
[0072] According to one preferred aspect of the present invention,
the image sensing apparatus of claim 1 is characterized in that a
top-side reference voltage of the A/D converter is set to narrow a
dynamic range in the film image sensing mode than in the normal
image sensing mode.
[0073] With this arrangement, the dynamic range of the A/D
converter is narrowed in the film image sensing mode, thus
processing an image signal in an optimal state to film image
sensing.
[0074] According to one preferred aspect of the present invention,
the film image sensing mode selection means comprises means for
detecting switching between the film image sensing mode and normal
image sensing mode.
[0075] With this arrangement, the top-side reference voltage of the
A/D converter can be switched by detecting the film image sensing
mode or normal image sensing mode.
[0076] In order to achieve the above objects, an image sensing
apparatus according to the present invention, which has a function
of sensing a photographic film image, comprises detection means for
detecting attachment of an adapter used for sensing a photographic
film image, and a noise reduction circuit, and a noise reduction
amount of the noise reduction circuit is switched in synchronism
with the attachment of the adapter detected by the detection
means.
[0077] According to one preferred aspect of the present invention,
the noise reduction circuit has a field memory or frame memory, and
executes field or frame correlation noise reduction.
[0078] According to one preferred aspect of the present invention,
the noise reduction circuit has a line memory, and executes line
correlation noise reduction.
[0079] It is still another object of the present invention to
provide an image sensing apparatus having a function of sensing a
photographic film, comprising a reversing circuit for reversing a
negative image on the photographic film to a positive image, and a
noise reduction circuit, wherein a noise reduction amount of the
noise reduction circuit is switched in synchronism with reversing
by the reversing circuit.
[0080] According to one preferred aspect of the present invention,
the noise reduction circuit has a field memory or frame memory, and
executes field or frame correlation noise reduction.
[0081] According to one preferred aspect of the present invention,
the noise reduction circuit has a line memory, and executes line
correlation noise reduction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0082] FIG. 1 is a block diagram showing the arrangement of a
conventional image sensing apparatus;
[0083] FIG. 2 is a circuit diagram showing an example of the
arrangement of a conventional noise reduction circuit;
[0084] FIG. 3 depicts the arrangement of a system in which a film
image obtained by attaching a film adapter to a video camera is
captured into a personal computer;
[0085] FIG. 4 is a graph for explaining differences between
negative and positive films on a color difference signal coordinate
system;
[0086] FIG. 5 is a block diagram for explaining the circuit
arrangement of a video camera to which the present invention is
applied;
[0087] FIG. 6 is a side view showing the structure of an inner
focus type lens;
[0088] FIG. 7 is a graph showing the characteristics of the inner
focus type lens;
[0089] FIG. 8 is a plan view showing an example of a switch panel
including various switches arranged on the video camera;
[0090] FIG. 9 is a block diagram showing the arrangement of a
camera signal processing circuit in the system shown in FIG. 5;
[0091] FIG. 10 is a circuit diagram showing the internal
arrangement of a negative/positive reversing circuit;
[0092] FIG. 11 is a block diagram showing the circuit arrangement
common to the individual embodiments of an image sensing apparatus
according to the present invention;
[0093] FIG. 12 is a graph showing the principle of automatic
negative/positive determination;
[0094] FIG. 13 is a flow chart showing operation according to the
first embodiment of the present invention;
[0095] FIG. 14 is a flow chart showing operation according to the
second embodiment of the present invention;
[0096] FIG. 15 is a flow chart showing operation according to the
third embodiment of the present invention;
[0097] FIG. 16 is a flow chart showing operation according to the
fourth embodiment of the present invention;
[0098] FIG. 17 is a flow chart showing operation according to the
first embodiment of the present invention;
[0099] FIG. 18 is a block diagram showing the circuit arrangement
of principal part according to the sixth embodiment of the present
invention;
[0100] FIG. 19 is a flow chart showing the processing according to
the sixth embodiment of the present invention;
[0101] FIG. 20 is a block diagram showing the circuit arrangement
of principal part according to the seventh embodiment of the
present invention;
[0102] FIG. 21 is a block diagram showing the circuit arrangement
of principal part according to the eighth embodiment of the present
invention;
[0103] FIG. 22 is a block diagram showing the eighth embodiment of
the present invention implemented by a microcomputer;
[0104] FIG. 23 is a graph showing a determination region in the
eighth embodiment;
[0105] FIG. 24 is a flow chart showing the processing according to
the eighth embodiment of the present invention;
[0106] FIG. 25 is a block diagram showing the circuit arrangement
of principal part according to the ninth embodiment of the present
invention;
[0107] FIG. 26 is a block diagram showing the internal circuit
arrangement of principal blocks of a negative/positive reversing
circuit according to the ninth embodiment of the present
invention;
[0108] FIG. 27 is a graph showing the principle of automatic
negative/positive determination used in the ninth embodiment;
[0109] FIG. 28 is a flow chart showing the processing according to
the ninth embodiment of the present invention;
[0110] FIG. 29 is a block diagram showing a circuit arrangement
common to the individual embodiments of an image sensing apparatus
according to the present invention;
[0111] FIG. 30 is a flow chart showing operation according to the
10th embodiment of the present invention;
[0112] FIG. 31 is a flow chart showing operation according to the
11th embodiment of the present invention;
[0113] FIG. 32 is a flow chart showing operation according to the
12th embodiment of the present invention;
[0114] FIG. 33 is a block diagram for explaining the circuit
arrangement of a video camera (video built-in type camera)
according to the 13th embodiment of the present invention;
[0115] FIG. 34 is a plan view showing an example of a switch panel
including various switches arranged on the video built-in type
camera in the 13th embodiment of the present invention;
[0116] FIG. 35 shows a screen display example of the video built-in
type camera in the 13th embodiment of the present invention;
[0117] FIG. 36 is a flow chart showing the 13th embodiment of the
present invention;
[0118] FIG. 37 is a flow chart showing the 14th embodiment of the
present invention;
[0119] FIG. 38 is a flow chart showing the 15th embodiment of the
present invention;
[0120] FIG. 39 is a block diagram for explaining the circuit
arrangement of a video camera (video built-in type camera)
according to the 16th embodiment of the present invention;
[0121] FIGS. 40A and 40B are timing charts in the seventh
embodiment of the present invention;
[0122] FIG. 41 is a flow chart showing the 16th embodiment of the
present invention;
[0123] FIG. 42 is a block diagram of an image sensing apparatus
according to the 17th embodiment of the present invention;
[0124] FIG. 43 is a circuit diagram of an A/D converter shown in
FIG. 42;
[0125] FIG. 44 is a block diagram showing the arrangement according
to the 18th embodiment of the present invention;
[0126] FIG. 45 is a circuit diagram showing an example of a film
adapter detection circuit; and
[0127] FIG. 46 is a block diagram showing the arrangement according
to the 19th embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0128] An image sensing apparatus (the first to 19th embodiments)
according to the present invention will be described in detail
hereinafter with reference to the accompanying drawings. Note that
an image sensing apparatus according to each of the first to 15th
embodiments pursues automatic detection of attachment of a film
adapter, and an image sensing apparatus according to each of the
16th to 19th embodiments automatic setting of the optimal image
sensing condition for image sensing via a film adapter.
[0129] <Arrangement of Image Sensing Apparatus> . . . Basic
Arrangement
[0130] The first to 19th embodiments are directed to an image
sensing apparatus which allows to sense images on a negative or
positive film using a film adapter which is detachably attached to
a video camera or the like. The arrangement of an image sensing
apparatus as a premise of each embodiment will first be explained
below. A video camera shown in FIGS. 3 to 10 has a basic
arrangement of video cameras of the first to 19th embodiments and,
hence, the basic arrangement is modified as needed in the video
camera of each of the first to 19th embodiments.
[0131] FIG. 3 depicts a state wherein a film adapter 803 is
attached to a video camera 804 to sense an image on a negative film
801 clamped by a film holder 802. The film adapter 803 has a
backlight (not shown) for illuminating the negative film 801, and
an optical image transmitted through the film 801 is sensed by the
video camera 804.
[0132] In this case, when the video camera 804 has a
(negative/position conversion) function of converting a negative
image into a positive image, the output electrical signal is a
video signal of a positive image.
[0133] When this output signal is input to a personal computer 805,
the positive image can be captured on a memory in the personal
computer. Since the frames on a negative film have a uniform size
and the light source can be standardized by the backlight, the
system shown in FIG. 3 allows the user to capture a picture image
into the personal computer more easily than sensing a so-called
silver halide picture printed on a photographic print paper
sheet.
[0134] Video information on a negative film is literally a reversed
one of a positive image.
[0135] FIG. 4 shows given color difference signals (R-Y, B-Y) of a
color negative film using vectors in both negative and positive
states. The abscissa is the color difference signal B-Y axis, and
the ordinate is the color difference signal R-Y axis. As can be
seen from FIG. 4, the color difference vectors are inverted through
180.degree. between the two states before and after
negative/positive reversing.
[0136] FIG. 5 is a schematic block diagram showing the arrangement
of the video camera shown in FIG. 3, and FIG. 6 shows a portion
associated with the negative/positive reversing function of that
camera in detail.
[0137] Referring to FIG. 5, reference numeral 401 denotes a
subject. Normally, a person, landscape, or the like becomes the
object to be sensed. However, when a negative film or slide film is
attached as the subject 401 to the film adapter, the subject 401
has a very small distance from the front surface of a lens
system.
[0138] Reference numeral 402 denotes a fixed first unit lens; 403,
a magnification lens; 404, an iris; 405, a fixed third unit lens;
and 406, a focus-compensation lens which has both a focus
adjustment function and a function of compensating for shifts of a
focal plane upon variable magnification. Reference numeral 407
denotes an image sensing element such as a CCD; 408, an AGC
circuit; and 409, a signal processing circuit, the details of which
are shown in FIG. 6. Reference numerals 410, 411, and 412
respectively denote a magnification lens motor, IG motor, and
focus-compensation lens motor for respectively driving the
magnification lens, iris, and focus-compensation lens. Reference
numerals 413, 414, and 415 respectively denote drivers for
respectively supplying driving currents to the magnification lens
410, iris 411, and focus-compensation lens 412.
[0139] Reference numeral 416 denotes an iris control circuit; 417,
an AF control circuit for processing an evaluation value used in
auto-focus (AF) control; 418, a lens/camera control circuit for
controlling the lens and camera; 419, a system controller for
controlling the system of the entire video camera; 420, a switch
panel equipped in the video camera; and 421, 422, and 423,
communication lines for data communications among the individual
circuits.
[0140] FIG. 6 shows a lens system made up of the fixed first unit
lens 402, magnification lens 403, iris 404, fixed third unit lens
405, and focus-compensation lens 405 shown in FIG. 5.
[0141] A lens arrangement of this type is called an inner focus
type lens system. FIG. 7 shows, as a plurality of loci, the imaging
plane in-focus positions of the focus-compensation lens with
respect to subject distances corresponding to focal lengths. In
FIG. 7, the abscissa plots the magnification lens position, and the
ordinate plots the focus-compensation lens position.
[0142] In the lens system shown in FIG. 6, when an in-focus state
is to be obtained on the image sensing surface 407 by moving the
focus-compensation lens, the position of the focus-compensation
lens for each subject distance changes in accordance with the focal
length. Especially, on the short focal length side (the left side
in FIG. 7), the minimum value of the subject distance with which an
in-focus state can be attained indicates a position immediately
before the first unit lens 402 by moving the focus-compensation
lens 406 to a position in the vicinity of the closest-distance end.
In other words, an in-focus state can be obtained even when the
subject is at a position immediately before the lens 402.
[0143] In order to accurately trace the loci shown in FIG. 7, the
positions of the magnification lens and focus-compensation lens can
be detected by counting driving pulses to be supplied from the
lens/camera control circuit 418 to the drivers 413 and 415 using an
internal counter of the lens/camera control circuit 418.
[0144] A curve 901 in FIG. 7 is an in-focus curve when a subject is
placed within a very short distance range, i.e., within several cm
immediately before the lens 402. As can be seen from FIG. 7, an
in-focus region of the magnification lens 403 corresponding to this
subject distance range is a limited short-focal length region
within a region 902. Hence, when an image on a film located very
close to the lens 102 is sensed using the film adapter shown in
FIG. 3, a combination of the positions of the magnification lens
403 and the focus-compensation lens 406 must fall within the region
904 bounded by three margins 901, 902, and 903 in FIG. 7.
[0145] Therefore, when an image on a film is sensed using the film
adapter, the positions of the magnification lens and
focus-compensation lens must be changed using a predetermined
switch (one in a switch panel 420).
[0146] FIG. 8 shows an example of the internal arrangement of the
switch panel 420 arranged on the camera. A switch setup state for
setting the lens system to be suitable for film image sensing will
be described below. A magnification setting switch 1104 in the
switch panel 420 is set, so that the position of the magnification
lens falls with the region 902 in FIG. 7. Thereafter, the
focus-compensation lens is moved to a position within the region
904 in FIG. 7 by enabling an auto-focus circuit or by operating a
focus-compensation lens manual movement switch 1105.
[0147] FIG. 9 is a block diagram showing the arrangement in the
camera signal processing circuit 409, and a portion bounded by the
broken line corresponds to the camera signal processing circuit
409.
[0148] Reference numeral 501 denotes an image sensing optical
system, which simply illustrates the lens system made up of the
lenses 402, 403, 405, and 406, and iris 404 shown in FIG. 6, in
FIG. 9. Reference numeral 502 denotes a YC signal generation
circuit, which separates luminance signals Y.sub.H and Y.sub.L and
chrominance signals R (red) and B (blue) from the output from the
AGC circuit 408, and outputs these signals. Reference numerals 503
and 504 respectively denote R and B gain control circuits. The
levels of color difference signals R-Y and B-Y are respectively
detected by a camera control circuit 507, and the gains of the gain
control circuits 503 and 504 are adjusted to obtain appropriate
white balance. Thereafter, the circuits 503 and 504 respectively
output adjusted chrominance signals R' and B'.
[0149] Reference numeral 505 denotes a color difference signal
generation circuit for generating color difference signals R-Y and
B-Y on the basis of the signals Y.sub.L, R, and B; 506, an encoder
for generating a television signal on the basis of the signals
Y.sub.H, R-Y, and B-Y; 508, a synchronization signal generation
circuit for supplying a synchronization signal to the camera
control circuit; and 509, a reference signal generation circuit for
generating reference signals [R-Y].sub.ref and [B-Y].sub.ref for
adjusting the gains of the gain control circuits 503 and 504.
[0150] An image memory 511 is connected to the camera control
circuit 507 via a communication line 510, and stores image data of
a still image. When the user selects a still image sensing mode
using a mode selection switch 1101 (FIG. 8) for switching the image
sensing mode between a moving image sensing mode and still image
sensing mode, image data can be stored in the memory 511. When the
user presses a trigger switch 1102 on the switch panel 420, the
luminance and chrominance signals output from the YC signal
generation circuit 502 and the color difference signal generation
circuit 505 are stored in the memory 511, and still image
information is then output from the memory 511 to the encoder 506
in accordance with a control signal from the control circuit 507.
In this manner, the still image sensing mode is set.
[0151] When the moving image sensing mode is selected (when the
switch 1101 is flipped to the right side), or when the still image
sensing mode is selected but the trigger switch 1102 is not
pressed, image information from the circuits 502 and 505 passes
through the image memory 511.
[0152] When the video camera of the present invention has both the
moving and still image sensing modes, two trigger switches 1102 may
be arranged in correspondence with moving and still images.
However, in terms of a size reduction, cost reduction, and easy
operation of the apparatus, a single trigger switch is designed to
be used for sensing both moving and still images, as shown in FIG.
8.
[0153] The negative/positive reversing function will be explained
below.
[0154] In FIG. 9, a negative/positive reversing circuit 513 is
inserted before the image memory 511. The negative/positive
reversing circuit reverses the signals Y.sub.H, R-Y, and B-Y. FIG.
10 shows the arrangement of the negative/positive reversing
circuit.
[0155] In FIG. 10, as for the signal Y.sub.H, a circuit 701
reverses a light portion of the input luminance signal to a dark
portion and vice versa. That is, for example, as for the input
luminance signal, the absolute value of the luminance signal, which
falls within the luminance level range from black level as a black
level reference to 100% white level is subtracted from 100% white
level, thereby extracting a density-reversed luminance component
with reference to 100% white level.
[0156] On the other hand, a circuit 703 reverses the signal R-Y in
an opposite direction on the R-Y axis and a circuit 705 reverses
the signal B-Y in an opposite direction on the B-Y axis in
accordance with the conversion characteristics shown in FIG. 4. In
this manner, by reversing the luminance and color difference
signals, a negative image can be converted into a positive
images.
[0157] Switches 702, 704, and 706 shown in FIG. 10 operate in
cooperation with each other by a negative/positive reversing ON/OFF
signal. When the negative/positive reversing function is ON, these
switches select the reversed signals; otherwise, they select input
signals to output them from the negative/positive reversing circuit
513.
[0158] The negative/positive reversing ON/OFF signal is output from
the camera control circuit 507. Whether or not the
negative/positive reversing function is executed can be selected by
the operator using a switch 1103 (FIG. 8) in the switch panel 420.
The camera control circuit 507 receives this selection information
from the communication line 421 via the communication line 423,
system controller 419, communication line 422, and lens/camera
control circuit 418, as shown in FIGS. 5 and 9, and outputs a
negative/positive reversing ON/OFF signal 512 to the circuit 513 on
the basis of the received information.
[0159] The overall arrangement of the video camera apparatus having
the still image sensing mode and negative/positive reversing
function has been described.
[0160] <First Embodiment>
[0161] The arrangement according to the first embodiment of the
present invention will be described below.
[0162] The video camera system described above with the aid of
FIGS. 3 to 10 requires the user setting of the image sensing mode
using the film adapter via the switch shown in FIG. 8. However,
unlike the video camera system described above with the aid of
FIGS. 3 to 10, the video camera of the first embodiment determines
based on an image signal whether or not the film adapter is
attached, thus relieving the operator of operation of various
switches shown in FIG. 8. That is, the first embodiment does not
determine actual attachment of the adapter but determines whether
or not an image on a film is to be sensed. When an image signal
indicating film image sensing is obtained, it is determined that
the film adapter is attached, and the user wants to sense an image
on that film as a still image.
[0163] The characteristic feature of the first embodiment lies in
the internal arrangement of the camera signal processing circuit
409, which is shown in FIG. 11. Note that FIG. 11 shows changed
peripheral portions of the camera control circuit 507 shown in FIG.
9.
[0164] In the first embodiment, a microcomputer is used as a camera
control circuit 105, and some other functions are further added to
the above-mentioned system.
[0165] Since the camera control circuit 105 comprises a
microcomputer, signals R-Y and B-Y output from the color difference
signal generation circuit 505 are converted into digital signals by
A/D converters 101 and 102, and the obtained digital signals are
input to the camera control circuit 105.
[0166] The outputs from the A/D converters 101 and 102 are
respectively input to the camera control circuit 105 via terminals
106 and 107, and are used for controlling the R and B gain control
circuits 503 and 504 described above with the aid of FIG. 9.
[0167] On the other hand, the outputs from the A/D converters 101
and 102 are also input to integrators 103 and 104, and the integral
results are input to the control circuit 105 via terminals 108 and
109.
[0168] When light transmitted through a color negative film
illuminated by a predetermined backlight is sensed by the video
camera and the obtained color difference signals are integrated by
the integrators 103 and 104, the obtained R-Y and B-Y components
are roughly distributed as color difference vectors within a range
indicated by a region on a color difference vector coordinate
system shown in FIG. 12.
[0169] Hence, whether or not an image on a negative film is sensed
can be detected in such a manner that color difference component
signals (R-Y and B-Y) input from the terminals 108 and 109 are
monitored to detect if color difference vectors are included with
the region 201, i.e., an R-Y component falls within a determination
range 202 (FIG. 12) and a B-Y component falls within a
determination range 203.
[0170] FIG. 13 is a flow chart showing the control for detecting
attachment of the film adapter and automatic selection of the film
image sensing mode in the camera control circuit 105.
[0171] When execution of the processing starts in step A301, it is
checked in step A302 if a signal R-Y input via the terminal 109
falls with the determination range 202. If the signal R-Y falls
outside the determination range 202, the camera is set in the
moving image mode in step A306. That is, the image memory 511 is
set in a through state, and the camera control circuit 507 supplies
a control signal 512 to the negative/positive reversing circuit 513
to disable the negative/positive reversing function so as not to
execute negative/positive reversing.
[0172] On the other hand, if it is determined that the signal R-Y
falls within the determination range 202, it is checked in step
A303 if a signal B-Y input from the integrator 103 via the terminal
108 falls within the determination range 203. If the signal R-Y
falls outside the determination range, the flow similarly advances
to step A306. On the other hand, if it is determined in step A303
that the signal B-Y falls within the determination range 202, the
camera is set in the film adapter mode, i.e., the film image
sensing mode in step A304. More specifically, the camera stands by
to capture a still image into the image memory 511 when the trigger
switch 1102 (FIG. 8) is turned on, and the camera control circuit
507 supplies the control signal 512 to the negative/positive
reversing circuit 513 to enable the negative/positive reversing
function so as to execute negative positive reversing.
[0173] In the video camera of the first embodiment with the
above-mentioned arrangement, the operator need not manually select
the "operation of the negative/positive "reversing function" using
the switch 1103, and the camera can be automatically set in the
film image sensing mode and enable the negative/positive reversing
function only when an image on a negative film is sensed.
[0174] Therefore, for example, when a negative film image is to be
captured in the moving image mode which remains set immediately
after normal video image sensing, a photographic film capture mode
can be automatically and smoothly selected by only attaching the
film adapter.
[0175] Note that the above-mentioned negative film automatic
determination scheme is not limited to only one scheme, and
negative film automatic determination may also be implemented by
methods disclosed in Japanese Laid-Open Patent Nos. 61-218268 and
62-10967 assigned to the same assignee as the present invention.
Such specifications are incorporated herein by reference.
[0176] <Second Embodiment>
[0177] In the first embodiment, whether or not the film adapter is
attached, i.e., whether or not the user wants to select the film
image sensing mode, is determined by checking on the basis of color
difference signals if the camera is sensing light transmitted
through a film. The second embodiment implements this determination
on the basis of the lens position in an imaging plane in-focus
state upon sensing a subject.
[0178] FIG. 14 is a flow chart showing the processing in the camera
control circuit 105 in the camera signal processing circuit 409
according to the second embodiment of the present invention.
[0179] In the flow chart shown in FIG. 14, when execution of the
processing starts in step A401, it is checked in step A402 if the
position of the magnification lens falls within the range of a
region 902 shown in FIG. 7. If the position of the magnification
lens falls outside the range, the flow advances to step A405 as in
the first embodiment, and the camera is set in a state for sensing
a normal subject image in the moving image mode.
[0180] On the other hand, if it is determined in step A402 that the
position of the magnification lens falls within the range of the
region 902, it is checked in step A403 if the position of the
focus-compensation lens falls within the range on the
closest-distance side of a curve 904 (the position condition of the
focus-compensation lens changes depending on the position of the
magnification lens). If the position of the focus-compensation lens
falls outside that range, the processing in step A405 is executed
in the same manner as described above.
[0181] If it is determined in step A403 that the position of the
focus-compensation lens falls within the range 903 in FIG. 7, it is
determined that the film adapter 803 is attached, and the video
camera is set in the film image sensing mode in step A404.
[0182] Since the state of the lens system is used as a
determination condition, as described above, whether or not a
photographic film image is sensed at the closest distance, i.e.,
using the film adapter can be clearly determined. Hence, the camera
can be automatically set in the photographic film image sensing
mode without any operation errors.
[0183] <Third Embodiment>
[0184] In the third embodiment, whether or not the camera is to be
set in the film image sensing mode is determined in consideration
of both the determination condition of the first embodiment
(determination based on color difference signals) and the
determination condition of the second embodiment (i.e., the lens
position in the imaging plane in-focus state described above with
the aid of FIG. 7).
[0185] FIG. 15 is a flow chart showing the processing in the camera
control circuit 507 in the camera signal processing circuit 409
according to the third embodiment of the present invention.
[0186] Steps B402 and B403 in FIG. 15 are the same as steps A402
and A403 in FIG. 14, and steps B302 to B307 in FIG. 15 are the same
as steps A302 to A307 in FIG. 13.
[0187] In the flow chart shown in FIG. 15, when execution of the
processing starts, it is checked in step B402 if the position of
the magnification lens falls within the range of the region 902
(FIG. 7). If the position of the magnification lens falls outside
the range, the flow advances to steps B306 and B307 as in the first
embodiment, and the camera is set in a state for sensing a normal
subject image in the moving image mode.
[0188] On the other hand, if it is determined in step B402 that the
position of the magnification lens falls within the range of the
region 902 (FIG. 7), it is checked in step B403 if the position of
the focus-compensation lens falls within the range on the
closest-distance side of the curve 904 (the position condition of
the focus-compensation lens changes depending on the position of
the magnification lens). If the position of the focus-compensation
lens falls outside that range, the processing in steps B306 and
B307 is executed in the same manner as described above. If it is
determined in step B403 that the position of the focus-compensation
lens falls within the range 903 in FIG. 7, the states of color
difference signals R-Y and B-Y are detected in steps B302 and B303
as in the first embodiment. If the color difference vectors fall
within the range of the region 201, it is determined that the film
adapter is attached, and a photographic film image is to be sensed.
Hence, the video camera is set to capture a negative-to-positive
reversed image in the film image sensing mode in steps B304 and
B305.
[0189] As described above, by adding the state of the lens system
as the determination condition, whether or not a photographic film
image is sensed at the closest distance, i.e., using the film
adapter can be clearly determined. Hence, the camera can be
automatically set in the photographic film image sensing mode
without any operation errors.
[0190] With the above arrangement, when the film adapter is
attached, the camera can be automatically set in the negative film
image sensing mode. Hence, not only cumbersome operations are
precluded, but also the camera can prevent a negative film image
from being captured into a personal computer in the moving image
mode if the operator forgets to do required operations.
[0191] <Fourth Embodiment>
[0192] In the first and second embodiments, the camera indirectly
determines based on the color difference signals or lens position
if the user wants to do film image sensing. In the fourth
embodiment, when the operator operates the negative/positive
reversing function selection switch 1103 to enable the
negative/positive reversing function, the camera is automatically
set in the film image sensing mode.
[0193] The camera of the fourth embodiment can be realized by
changing processing in the camera control circuit 105 (signal
processing circuit 409) of the basic video camera shown in FIGS. 3
to 10. For this reason, the fourth embodiment is advantageous in
terms of cost.
[0194] Hence, the schematic arrangement of the overall camera
apparatus of the fourth embodiment is the same as that shown in
FIG. 5, and the internal arrangement of the camera signal
processing circuit 409 is the same as that shown in FIG. 9.
[0195] In FIG. 16, when execution of the processing starts in step
A501, it is checked in step A502 if the operator has enabled the
negative/positive reversing function. As described above, the
communication lines 422 and 423 carry ON information of the
negative/positive reversing function.
[0196] If it is determined in step A502 that the negative/positive
reversing function is ON, the camera is set in the still image
mode, and thereafter, a negative/positive reversing ON signal is
output to the negative/positive reversing circuit 513 via the
signal line 512 to enable the negative/positive reversing function,
in steps A503 and A504. With this processing, an image obtained by
converting a negative film image into a positive image can be
displayed or recorded.
[0197] On the other hand, if it is determined in step A502 that the
negative/positive reversing function is OFF, the camera is set in
the moving image mode, and thereafter, a negative/positive
reversing OFF signal is output to the negative/positive reversing
circuit 513 via the signal line 512 to disable the
negative/positive reversing function, in steps A505 and A506. In
this manner, a normal moving image sensing mode is set.
[0198] With the above arrangement, even in a camera which does not
have any function of automatically determining negative film image
sensing, the camera is automatically set in the still image mode
when the negative/positive reversing function is ON. Hence,
cumbersome operations are alleviated, and the camera can prevent a
negative film image from being unwontedly captured in the moving
image mode if the operator forgets to do required operations.
[0199] <Fifth Embodiment>
[0200] In the fifth embodiment, the present invention is applied to
a video camera having a negative/positive reversing function. In
this embodiment, if the color difference signals of an image signal
detected by an image sensing element fall within a predetermined
range, the negative/positive reversing function is automatically
enabled without bothering the user. In this manner, an image on a
negative film set in the film adapter is captured as a positive
image.
[0201] The hardware arrangement of the video camera of the fifth
embodiment is the same as that in the first embodiment, but the
control sequence in the camera control circuit 105 is different
from that in the first embodiment.
[0202] In the fifth embodiment, as in the first embodiment, whether
or not a negative film image is sensed can be detected in such a
manner that color difference component signals input from the
terminals 108 and 109 are monitored by the camera control circuit
105 to check if the R-Y component falls within the determination
range 202 (FIG. 12) and the B-Y component falls within the
determination range 203 (FIG. 12).
[0203] FIG. 17 is a flow chart showing the control sequence for
determining whether or not negative/positive reversing must be
done.
[0204] That is, FIG. 17 is a flow chart for detecting attachment of
the film adapter and automatically setting the camera in the film
image sensing mode in the camera control circuit 105.
[0205] When execution of the processing starts in step C301, it is
checked in step C302 if a signal R-Y input from the integrator 104
via the terminal 109 falls within the determination range 202. If
the signal R-Y falls outside the determination range 202, the
camera is set in the moving image mode in step C305. More
specifically, the image memory 511 is set in a through state, and
the camera control circuit 105 supplies a control signal 512 to the
negative/positive reversing circuit 513 to disable the
negative/positive reversing function so as not to execute
negative/positive reversing.
[0206] On the other hand, if it is determined in step C302 that the
signal R-Y falls within the determination range 202, it is checked
in step C303 if a signal B-Y input from the integrator 103 via the
terminal 108 falls within the determination range 203. If the
signal B-Y falls outside the determination range 203, the flow
advances to step C305 in the same manner as described above. On the
other hand, if it is determined in step C303 that the signal B-Y
falls within the determination range 203, the camera is set in the
film adapter mode, i.e., film image sensing mode, in step C304.
That is, the camera stands by to capture a still image into the
image memory 511 when the trigger switch is turned on, and the
camera control circuit 105 supplies the control signal 512 to the
negative/positive reversing circuit 513 to enable the
negative/positive reversing function so as to execute negative
positive reversing.
[0207] Conventionally, the operator must manually select the
"operation of the negative/positive reversing function" using a
predetermined switch (e.g., 1103 in FIG. 8) in the switch panel
420. However, when the circuit is arranged and controlled like in
the fifth embodiment, the video built-in type camera can be
automatically set in the film image sensing mode and enable the
negative/positive reversing function when a negative film image is
sensed. Hence, even when a negative film image is to be captured in
the moving image mode which remains set immediately after normal
video image sensing, a photographic film capture mode can be
automatically and smoothly selected by only attaching the film
adapter. Also, an image can be prevented from being reversed when a
slide film (positive film) is set or in a normal video image
sensing mode.
[0208] <Sixth Embodiment>
[0209] In the fifth embodiment, whether or not a negative film is
set in the adapter is determined based on color difference signals
alone. Hence, the color difference signals may vary depending on
the types of films or the state of images printed on a film, and
determination errors may be produced. The sixth embodiment has as
its principal object to prevent determination errors in the fifth
embodiment.
[0210] FIG. 18 is a block diagram showing the circuit arrangement
of a camera control circuit 902 and its peripheral circuits in the
camera signal processing circuit 409 in the sixth embodiment. The
difference from the camera (FIG. 11) of the fifth embodiment is
that negative film automatic determination grant information 901
and negative/positive reversing grant information 510 are
transmitted via the communication line 421. Both the negative film
automatic determination grant signal 901 and negative/positive
reversing grant signal 510 are generated in practice based on the
states of predetermined switches in the switch panel 420. More
specifically, when the user operates such predetermined switches,
if the negative film automatic determination grant signal 901 is
"1", the user has given a grant to the camera itself to do negative
film automatic determination; if the negative/positive reversing
grant signal 510 is "1", the user himself or herself has given a
grant to the camera to do automatic negative/positive reversing on
the basis of the negative film automatic determination result.
[0211] As the characteristic feature of the sixth embodiment, the
operator can select whether an automatic negative film image
sensing determination function is ON/OFF, so as not to produce
detection errors of the automatic negative/positive image sensing
determination function described in the fifth embodiment. If the
automatic determination is disabled, negative/positive reversing
can be forcibly done. Such detection errors of the automatic
negative film image sensing determination function are often
produced when a subject image having color difference vectors
similar to those of a negative film is sensed.
[0212] FIG. 19 is a flow chart showing the processing in the camera
control circuit 902 in the arrangement shown in FIG. 18. Note that
the contents of steps D302 to D305 in FIG. 19 are the same as those
in steps C302 to C305 in the fifth embodiment (FIG. 17).
[0213] In FIG. 19, when execution of the processing starts in step
A601, it is checked in step A602 based on the grant signal 901 if
the automatic negative film image sensing determination function is
to be enabled. If the automatic negative film image sensing
determination function is to be enabled (ON), the flow advances to
step D302 to check if a signal R-Y input via the terminal 109 falls
with the determination range 202 (FIG. 12). If the signal R-Y falls
outside the determination range 202, the camera control circuit 902
supplies a control signal 512 to the negative/positive reversing
circuit 513 to disable the negative/positive reversing function so
as not to execute negative/positive reversing, in step S305.
[0214] On the other hand, if it is determined in step D302 that the
signal R-Y falls within the determination range 202, it is checked
in step D303 if a signal B-Y input from the integrator 103 via the
terminal 108 falls within the determination range 203. If the
signal B-Y falls outside the determination range 203, the flow
advances to step D305 to disable the negative/positive reversing
function of the negative/positive reversing circuit 513.
[0215] On the other hand, if it is determined in step D303 that the
signal B-Y falls within the determination range 203, the camera is
set in the film image sensing mode and the negative/positive
reversing function of the negative/positive reversing circuit 513
is enabled by the control signal S12 from the camera control
circuit 902, in step D304.
[0216] If it is determined in step A602 that the automatic negative
film image sensing determination function is disabled, it is
determined in step A606 based on the negative/positive reversing
grant signal 510 if the operator has selected execution of
negative/positive reversing. If negative/positive reversing has
been granted, the negative/positive reversing function is enabled
by the negative/positive reversing ON/OFF control signal 512 from
the camera control circuit 902 in step A608.
[0217] If it is determined in step A606 that the negative/positive
reversing is denied, the negative/positive reversing function is
disabled by the negative/positive reversing ON/OFF control signal
512 from the camera control circuit 902 in step D305. The table
below summarizes the control sequence shown in FIG. 19.
1 TABLE Grant To Do Automatic Negative/Positive Reversing "1" "0"
Grant To Do "1" Depending on R-Y ON Automatic and B-Y Negative Film
"0" Depending on R-Y OFF Determination and B-Y
[0218] With the above-mentioned circuit arrangement, the video
built-in camera allows the operator to select the ON/OFF state of
the automatic negative film image sensing determination function so
as to prevent its detection errors and the like from being
produced, and also allows the operator to select whether or not
negative/positive reversing is to be executed when automatic
determination is disabled.
[0219] <Seventh Embodiment>
[0220] FIG. 20 is a block diagram showing the arrangement according
to the seventh embodiment of the present invention. The difference
from the first embodiment (FIG. 9) is that a YC signal generation
circuit 1103 generates three primary color signals R, G, and B.
[0221] The R and B signals output from the YC signal generation
circuit 1103 of the fifth embodiment are input to a color
difference signal generation circuit 1101 via the gain control
circuits 503 and 504. The color difference signal generation
circuit 1101 covert R, G, and B signals into signals Y, R-Y, and
B-Y using known conversion formulas, i.e., those described in Nihon
Hoso Kyokai ed., "NHK color television textbook (Vol. 1)", p. 28,
formulas (2.1):
Y=0.30R+0.59G+0.11B
R-Y=0.70R-0.59G-0.11B
B-Y=-0.30R-0.59G+0.89B
[0222] Since the circuit arrangement of that portion is known to
those who are skilled in the art, a detailed description thereof
will be omitted. Of the output signals from the color difference
signal generation circuit 1101, the signals R-Y and B-Y are input
to a camera control circuit 1102.
[0223] When a microcomputer is used as the camera control circuit
1102 as in the above embodiments, the peripheral circuits of the
camera control circuit 1102 have the same arrangement as that shown
in FIG. 11. When the camera control circuit 1102 comprises a
microcomputer, the sequence of the processing executed by the
camera control circuit 1102 is the same as that shown in the flow
chart in FIG. 17 or 19.
[0224] <Eighth Embodiment>
[0225] FIG. 21 is a block diagram showing the arrangement of the
eighth embodiment according to the present invention. In FIG. 21,
the same reference numerals denote blocks having the same functions
as those in FIG. 9 (first embodiment), FIG. 20 (seventh
embodiment), and the like, and a detailed description thereof will
be omitted.
[0226] The eighth embodiment is characterized in that R, G, and B
signals output from the YC signal generation circuit 1103 are input
to and processed by a camera control circuit 1201 before they are
converted into color difference signals by the color difference
signal generation circuit 1101 in FIG. 21.
[0227] When the camera control circuit 1201 comprises a
microcomputer, the circuit arrangement of its peripheral circuits
is as shown in FIG. 22. That is, R, G, and B signals are
respectively A/D-converted by A/D converters 1404, 1403, and 1402,
and the digital signals are then integrated by integrators 1407,
1406, and 1405. These integral results are input to a microcomputer
1401 (1201). The basic concept is the same as that in FIG. 11.
[0228] When it is determined based on three primary color signals
R, G, and B whether or not a negative film image is sensed, it is
checked if a vector 1302 of a color synthesized based on the levels
of the three primary color signals is present within a region 1301
bounded by R, G, and B determination ranges 1303, 1304, and 1305,
as shown in FIG. 23.
[0229] FIG. 24 is a flow chart showing the processing of the
above-mentioned method implemented by the internal processing of
the camera control circuit 1201 (1401), and this processing is
obtained by partially modifying that shown in the flow chart of
FIG. 19. Note that steps B602, B606, and B608 in FIG. 24 are
substantially the same as steps A602, A606, and A608 in FIG. 19,
and steps E304 and E305 are the same as steps D304 and D305. when
the processing starts in step S701, it is checked based on the
automatic negative film image sensing determination grant signal
901 if the automatic negative film image sensing determination
function is to be enabled.
[0230] If the automatic negative film image sensing determination
function is to be enabled, the flow advances to step S703 and the
subsequent steps. If it is determined in step S703, S704, or S705
that the input signal falls outside the R, G, or B determination
range, the flow advances to step E305, and a negative/positive
reversing OFF signal is output onto the control line 512 to disable
the negative/positive reversing function.
[0231] On the other hand, if it is determined in step S703, S704,
and S705 that the input signal falls within the R, G and B
determination ranges, the flow advances to step E304, and a
negative/positive reversing ON signal is output onto the control
line 512 to enable the negative/positive reversing function.
[0232] If it is determined in step B602 that the automatic negative
film image sensing determination function is to be disabled,
whether or not the operator has selected execution of
negative/positive reversing is checked based on the
negative/positive reversing ON/OFF signal 510 in step B606.
[0233] If negative/positive reversing is to be executed, a signal
on the control line 512 is set in the ON state to execute
negative/positive reversing in step B608; otherwise, a signal on
the control line 512 is set in the OFF state in step E305.
[0234] With the above-mentioned arrangement, automatic
determination of negative film image sensing and automatic ON/OFF
control of the negative/positive reversing function can be done
using three primary color signals R, G, and B.
[0235] <Ninth Embodiment>
[0236] FIG. 25 is a block diagram showing the arrangement according
to the ninth embodiment of the present invention. In FIG. 25, the
same reference numerals denote blocks having the same functions as
those in FIGS. 20 and 21, and the like, and a detailed description
thereof will be omitted.
[0237] The arrangement shown in FIG. 25 is characterized in that Y,
R, G, and B signals output from the YC signal generation circuit
502 are input to a negative/positive reversing circuit 1601 to
reverse an image before they are input to a camera control circuit
1602, and negative-to-positive reversed signals are input to the
camera control circuit 1602.
[0238] FIG. 26 is a schematic diagram showing the internal
arrangement of the negative/positive reversing circuit 1601. The
negative/positive reversing circuit 1601 has the same purpose as
that shown in FIG. 10 (first embodiment). As for a luminance signal
Y, the negative/positive reversing circuit 1601 has the same
arrangement as that of the circuit 513.
[0239] R, G, and B signals are supplied to a conversion matrix
circuit 1706, and are converted into reversed three primary color
signals R', G', and B' by a conversion matrix (M).
[0240] As in FIG. 10, switches 1702, 1703, 1704, and 1705 are
respectively connected to the signals Y', R', G', and B' so that
whether to execute negative/positive reversing can be selected on
the basis of a negative/positive reversing function ON/OFF
signal.
[0241] When the camera control circuit 1602 comprises a
microcomputer, the arrangement of its peripheral circuits is as
shown in FIG. 22, as in the fourth embodiment.
[0242] FIG. 27 shows the concept of a color vector defined by the
R', G', and B' signal levels before and after executing the
negative/positive reversing function, and does not necessarily
match an actual signal level distribution. In FIG. 27, a color
vector 1802 before negative/positive reversing moves to, e.g., the
position of a vector 1807 after negative/positive reversing, which
is located outside a negative film image sensing determination
region 1801.
[0243] FIG. 28 is a flow chart showing the internal processing of
the camera control circuit 1602 when it comprises a microcomputer.
This processing is obtained by modifying the processing shown in
FIG. 19.
[0244] When the processing starts in step S1901, it is checked in
step S1902 based on the information of an automatic negative film
image sensing detection ON/OFF signal if the automatic negative
film image sensing determination function is to be enabled. If the
automatic negative film image sensing determination function is to
be enabled, the flow advances to step S1903 to check the status of
a "reversing flag" indicating whether or not negative/positive
reversing has already been done. If the reversing flag is 0, the
image has not been reversed yet. Hence, if it is determined in step
S1904, S1905, or S1906 that the input signal falls outside the R,
G, or B determination range, the reversing flag is set at 0 in step
S1915. Thereafter, the flow advances to step S1916, and a
negative/positive reversing OFF signal is output onto the control
line 512 to disable the negative/positive reversing function.
[0245] If it is determined in steps S1904, S1905, and S1906 that
the input signal falls inside the R, G, and B determination ranges,
the reversing flag is set at 1 in step S1907 to indicate that the
image has already been reversed. Thereafter, the flow advances to
step S1908, and a negative/positive reversing ON signal is output
onto the control line 512 to enable the negative/positive reversing
function.
[0246] If it is determined in step S1903 that the reversing flag is
1, a negative image has already been reversed to a positive image,
and a color vector defined by R', G', and B' signals input to the
camera control circuit 1602 falls outside the determination region
1802 in FIG. 27, e.g., within a region 1807. Hence, if it is
determined in step S1909, S1910, or S1911 that the input signal
falls outside the R, G, or B determination range, it is determined
that a negative film image is sensed.
[0247] Therefore, the flow advances to step S1908 to keep
outputting a negative/positive reversing ON signal onto the control
line 512. On the other hand, if it is determined in steps S1909,
S1910, and S1911 that the input signal falls inside the R, G, and B
determination ranges, it is determined that a negative film image
is not sensed, but a normal image is reversed and a color vector is
present inside the region 1802. Accordingly, the reversing flag is
set at 0 in step S1912. Thereafter, the flow advances to step S1913
and a negative/positive reversing OFF signal is output onto the
control line 512 to disable the negative/positive reversing
function.
[0248] If it is determined in step S1902 that the automatic
negative film image sensing determination function is disabled,
whether or not the operator has selected execution of
negative/positive reversing is checked based on the information of
a negative/positive reversing ON/OFF signal 510 in step S1914.
[0249] If negative/positive reversing is to be executed, the
reversing flag is set at 1 in step S1917, and a signal on the
control line 512 is set in the ON state to execute
positive/negative reversing in step S1914. Otherwise, the reversing
flag is set at 0 in step S1915, and a signal on the control line
512 is set in the OFF state in step S1915.
[0250] With the above-mentioned arrangement, automatic
determination of negative film image sensing and automatic ON/OFF
control of the negative/positive reversing function can be done
using R, G, and B signals output from the negative/positive
reversing circuit.
[0251] <10th Embodiment>
[0252] In the 10th embodiment, whether or not the still image
sensing mode is selected is checked based on color difference
signals, and negative/positive reversing is done when the still
image sensing mode is selected.
[0253] FIG. 29 shows the arrangement of the camera control circuit
105 and its peripheral circuits according to the 10th embodiment,
which are the same as those in the first embodiment (FIG. 11).
[0254] FIG. 30 is a flow chart showing the control sequence of the
10th embodiment. The difference from the control sequence of the
first embodiment (FIG. 13) is that the film image sensing mode is
selected in step A304 in the first embodiment but in step F304 in
the 10th embodiment.
[0255] In the still image sensing mode, a still image is captured
onto the image memory 511 when the trigger switch 1102 is turned
on, and negative/positive reversing is executed in step A305.
[0256] That is, in the 10th embodiment, if it is detected that a
negative film image is sensed, the still image sensing mode can be
automatically set. In this embodiment, since this state corresponds
to the attached state of the film adapter, a film image sensing
mode is set.
[0257] In the "film image sensing mode" in the first embodiment and
the like, the lens system is automatically set in a closeup image
sensing state, and the negative/positive reversing function is
enabled. On the other hand, in the "still image sensing mode" in
the 10th embodiment, a setting state for sensing not a moving image
but a still image (e.g., for broadening the dynamic range, and so
on) is selected.
[0258] With the above-mentioned arrangement and control of the
circuits, even when the operator does not manually select a
specific switch for executing the "operation" of the
negative/positive reversing function", the video built-in type
camera can be automatically set in the film image sensing mode and
can enable the negative/positive reversing function only when he or
she takes a picture of a negative film image.
[0259] Therefore, even when a negative film image is to be captured
in the moving image mode, which is still set immediately after
normal video image sensing, a photographic film capture mode can be
smoothly set by only attaching the film adapter without requiring
any complicated operations.
[0260] Note that the above-mentioned negative film automatic
determination scheme is not limited to only one scheme, and
negative film automatic determination may also be implemented by
methods disclosed in Japanese Laid-Open Patent Nos. 61-218268 and
62-10967 assigned to the same assignee as the present
invention.
[0261] <11th Embodiment>
[0262] In the 11th embodiment, whether or not the "still image
sensing mode" is selected is determined on the basis of the lens
position in the imaging plane in-focus state upon sensing a subject
image in addition to the color difference signals as in the 10th
embodiment.
[0263] In the flow chart shown in FIG. 31, when execution of the
processing starts in step C401, it is checked in step C401 if the
magnification lens falls within the range of the wide region 902 in
FIG. 7. If the magnification lens falls outside that range, the
flow advances to steps C408 and C409 as in the first embodiment. In
these steps, the camera is set in a state for sensing a normal
subject image in the moving image mode, and the negative/positive
reversing function is disabled.
[0264] If it is determined in step C402 that the magnification lens
position falls within the range of the region 902, it is checked in
step C403 if the focus-compensation lens position falls within the
range on the closest-distance side of the curve 904 (the position
condition of the focus-compensation lens changes depending on the
position of the magnification lens). If the position of the
focus-compensation lens falls outside that range, the processing in
step C405 is executed in the same manner as described above.
[0265] If it is determined in step C403 that the position of the
focus-compensation lens falls within the range 903 in FIG. 7, the
states of color difference signals R-Y and B-Y are detected in
steps C404 and C405 as in the third embodiment (FIG. 15). If the
color difference vector falls within the range 202, it is
determined that the film adapter is attached, and a photographic
film image is sensed. Thus, the camera is set in the still image
sensing mode and the negative/positive reversing function is
enabled in steps C406 and C407. In this manner, an image captured
onto the image memory 511 in the still image sensing mode is
displayed. Since the negative/positive reversing function is
enabled, the film image sensing mode is set.
[0266] As described above, since the state of the lens system is
added as a determination condition, whether or not a photographic
film image is sensed at the closest distance, i.e., using the film
adapter can be clearly determined. Hence, the camera can be
automatically switched to the still image sensing mode and negative
film image sensing mode without any operation errors.
[0267] With the above-mentioned arrangement, when the film adapter
is attached, the camera is automatically set in the still image
sensing mode, i.e., the negative film image sensing mode, the
operator is exempted from cumbersome operations, and the camera can
prevent a negative film image from being captured into a personal
computer in the moving image mode if the operator forgets to do
required operations.
[0268] <12th Embodiment>
[0269] FIG. 32 is a flow chart showing the processing in a camera
control circuit in a camera signal processing circuit according to
the 12th embodiment of the present invention. The schematic
arrangement of the overall camera of this embodiment is the same as
that shown in FIG. 5, and the internal arrangement of the camera
signal processing circuit is the same as that shown in FIG. 9.
[0270] The 12th embodiment has no automatic identification means of
negative/positive film image sensing unlike in the 10th and 11th
embodiments, and when the operator operates the switch 1103 to
enable to the negative/positive reversing function, the camera is
automatically switched to the still image mode.
[0271] This embodiment can be implemented by changing the
processing in the camera control circuit 105 in the camera signal
processing circuit 409. The schematic arrangement of the overall
camera of this embodiment is the same as that shown in FIG. 5, and
the internal arrangement of the camera signal processing circuit is
the same as that shown in FIG. 9.
[0272] In FIG. 32, when execution of the processing starts in step
S1301, it is checked in step S1302 if the operator has enabled the
negative/positive reversing function. As described above, the
communication lines 422 and 423 provide ON information of the
negative/positive reversing function.
[0273] If it is determined in step S1302 that the negative/positive
reversing function is ON, the camera is set in the still image
mode, and a negative/positive reversing ON signal is output to the
negative/positive reversing circuit 513 via the signal line 512 to
enable the negative/positive reversing function, in steps S1303 and
S1304. In this manner, a positive image obtained by converting a
negative film image can be displayed or recorded.
[0274] If it is determined in step S1302 that the negative/positive
reversing function is OFF, the camera is set in the moving image
mode, and a negative/positive reversing OFF signal is output to the
negative/positive reversing circuit 513 via the signal line 512 to
disable the negative/positive reversing function, in steps S1305
and S1306. In this way, a normal moving image sensing mode is
set.
[0275] With the above-mentioned arrangement, even in a camera
without any function of automatically determining negative film
image sensing, since the camera is automatically switched to the
still image mode when the negative/positive reversing function is
ON. Hence, the operator is free from cumbersome operations, and the
camera can prevent a negative film image from being captured into a
personal computer in the moving image mode if the operator forgets
to do required operations.
[0276] <13th Embodiment>
[0277] The 13th embodiment relates to a camera which has a moving
image sensing mode and a still image sensing mode that includes two
modes, i.e., sequential and single shot modes. In such camera, the
operator switches the image sensing mode in correspondence with his
or her purpose at that time.
[0278] The sequential shot mode mainly aims at avoiding loss of an
image sensing chance upon sensing a moving subject image as a still
image. When a negative film image is sensed as a still image using
the film adapter or the like, the subject is a complete still image
integrated with the camera. Hence, identical still images are
unwantedly sequentially sensed unless the sequential/single shot
selection switch is set at the single shot side. More specifically,
when the film adapter or the like is used, if the user forgets to
confirm if the image sensing mode is the single shot mode and to
operate the required switch, identical still images are unwantedly
sequentially sensed as in the above case.
[0279] To remove the above-mentioned shortcomings and to solve the
above problems, in the 13th embodiment, when a film image is
captured by the camera, the camera is automatically set in the
still image single shot mode.
[0280] FIG. 33 is a block diagram showing the 13th embodiment of
the present invention. In FIG. 33, the same reference numerals
denote the same parts as in the block diagram shown in FIG. 5, and
a detailed description thereof will be omitted.
[0281] In FIG. 33, the difference from the arrangement shown in
FIG. 5 is that a video signal output from the camera signal
processing circuit 409 is amplified by an amplifier 424, and the
amplified signal is displayed on an LCD (liquid crystal display)
426 via an LCD (liquid crystal) display circuit 425. The system
controller 419 supplies various display data as well as those for
image sensing modes to a character generator 427, which supplies
characters, marks, and the like corresponding to such various
display contents to the LCD display circuit 425, thus displaying
the data on the LCD 426 to be superposed on the video signal
supplied from the camera signal processing circuit 409.
[0282] The above-mentioned still image capture function will be
described in more detail below. As an advanced mode of the still
image sensing mode, a sequential shot function of sequentially
capturing still images for a plurality of frames at predetermined
time intervals by single trigger operation is known.
[0283] Since this sequential shot function can simultaneously sense
a plurality of still images of a moving subject, the photographer
need not carefully wait for an instantaneous image sensing chance,
and can select the best one from a series of still images. For this
reason, this function is important for cameras having the still
image sensing mode.
[0284] In case of a video built-in type camera, video information
is recorded by scanning a recording head on a recording medium at
high speed like helical scan video signal recording onto a magnetic
tape, and the recording width for one field or frame of a magnetic
tape in the longitudinal direction, which can form a still image,
is very small.
[0285] In other words, even when still images are sequentially
recorded at predetermined time intervals, the feed amount of the
magnetic tape in the longitudinal direction is very small, and a
mechanism used for sensing a moving image can be used without any
modifications. Also, as compared to the scale of a sequential shot
film feed device for a silver halide camera, the sequential shot
function of a still image is suitable for the video built-in type
camera.
[0286] An example of the operation method in the sequential shot
mode will be explained below with reference to FIGS. 34 and 35.
[0287] FIG. 34 shows an example of the switch panel 420 of the 13th
embodiment. In FIG. 34, when a switch 1501 is flipped to the
position of "still image sensing", and "negative/positive
reversing" is selected by a switch 1503, an indication 1604
indicating that the negative/positive reversing mode is currently
selected, and an indication ("still image sequential shot") 1603
indicating a mode of sensing a predetermined number of still images
at predetermined time intervals by single operation of a trigger
button 1602 are made together with a subject image 1602 in a finder
or monitor, as shown in FIG. 35.
[0288] When "moving image" is selected by the switch 1501, an
indication 1606 (letters of "moving image") is made at the position
1603.
[0289] The characteristic feature of the 13th embodiment will be
described below. In this embodiment as well, actual processing is
done by the camera control circuit in the camera signal processing
circuit 409 shown in FIG. 34. The arrangement of the camera control
circuit is the same as that of the first embodiment, and a detailed
description thereof will be omitted. The internal processing of the
camera control circuit will be described below with the aid of the
flow chart in FIG. 36.
[0290] FIG. 36 shows the processing for detection of film image
sensing and automatic selection of the still image single shot mode
in the camera control circuit 105 of the 13th embodiment.
[0291] When execution of the processing starts in step S1701, it is
checked in step S1702 if a signal R-Y input from the integrator 104
via the terminal 109 falls within the determination range 202. If
the signal R-Y falls outside the determination range 202, the
camera is set in the moving image mode in step S1706, and the image
memory 511 is set in a through state. By the processing in step
S1707, the camera control circuit 105 supplies a control signal 512
to the negative/positive reversing circuit 513 to disable the
negative/positive reversing function, so as not to execute
negative/positive reversing.
[0292] If it is determined in step S1702 that the signal R-Y falls
within the determination range 202, it is checked in step S1703 if
a signal B-Y input from the integrator 103 via the terminal 108
falls within the determination range 203. If the signal B-Y falls
outside the determination range, the flow advances to step S1706 to
set the moving image sensing mode.
[0293] On the other hand, if it is determined in step S1703 that
the signal B-Y falls within the determination range 203, the camera
is set in the still image sensing mode in step S1704, and stands by
to capture a still image into the image memory 511 when the trigger
switch is turned on. Also, in step S1705, the image sensing mode is
forcibly switched to the single shot mode independently of the
current image sensing mode.
[0294] The camera stands by to capture a still image into the image
memory 511 when the trigger switch is turned on, and the flow
advances to step S1708. In step S1708, the camera control circuit
105 supplies a control signal 512 to the negative/positive
reversing circuit 513 to enable the negative/positive reversing
function so as to execute negative/positive reversing.
[0295] More specifically, when it is detected that a negative film
image is sensed, the camera can be automatically set in the still
image sensing mode, and can also be set in the single shot
mode.
[0296] In this embodiment, since this state corresponds to the
attached state of the film adapter, a film image sensing mode is
set.
[0297] With the above-mentioned arrangement and control of the
circuits, even when the operator does not manually select the
"still image single shot mode" using the switch 1603, the video
built-in type camera can be automatically set in the film image
sensing mode and can enable the negative/positive reversing
function only when he or she takes a picture of a negative film
image.
[0298] Therefore, even when a negative film image is to be captured
in the moving image mode, which is still set immediately after
normal video image sensing, a photographic film capture mode can be
smoothly set by only attaching the film adapter without requiring
any complicated operations.
[0299] Note that the above-mentioned negative film automatic
determination scheme is not limited to only one scheme, and
negative film automatic determination may also be implemented by
methods disclosed in Japanese Laid-Open Patent Nos. 61-218268 and
62-10967 assigned to the same assignee as the present
invention.
[0300] <14th Embodiment>
[0301] FIG. 37 is a flow chart showing the internal processing of
the camera control circuit 105 in the camera signal processing
circuit 409 according to the 14th embodiment. In the fourth
embodiment, the lens position in the imaging plane in-focus state
upon sensing a subject image is added as a determination condition
in addition to that in the 13th embodiment.
[0302] In the flow chart shown in FIG. 37, when execution of the
processing starts in step S1801, it is checked in step S1802 if the
magnification lens falls within the range of the wide region 902 in
FIG. 7. If the magnification lens falls outside that range, the
flow advances to step S1809 to set the camera in a state for
sensing a normal subject image in the moving image mode as in the
fourth embodiment, and the negative/positive reversing function is
disabled in step S1810.
[0303] If it is determined in step S1802 that the magnification
lens position falls within the range of the region 902, it is
checked in step S1803 if the focus-compensation lens position falls
within the range on the closest-distance side of the curve 904 (the
position condition of the focus-compensation lens changes depending
on the position of the magnification lens). If the position of the
focus-compensation lens falls outside that range, the processing in
steps S1809 and S1810 is executed in the same manner as described
above.
[0304] If it is determined in step S1803 that the position of the
focus-compensation lens falls within the range 903 in FIG. 7, the
states of color difference signals R-Y and B-Y are detected in
steps S1804 and S1805, as in the above embodiment. If the color
difference vector falls within the range 201, since no film image
is sensed, the processing in steps S1809 and S1810 is executed.
[0305] If it is determined in steps S1804 and S1805 as a result of
detecting the states of the color difference signals R-Y and B-Y
that the color difference vector falls within the range 201, it is
determined that the film adapter is attached, and a photographic
film image is sensed. Hence, processing in steps S1806, S1807, and
S1808 is executed to forcibly set the camera in the still image
single shot mode, and thereafter, to enable the negative/positive
reversing function.
[0306] With this processing, the still image sensing mode and
single shot mode are set, so that a single still image is captured
onto the image memory 511 in response to ON operation of the
trigger switch, and is displayed on the display unit. Also, the
captured image is output to an external apparatus, and can be
recorded on a recording medium such as a magnetic tape (not shown).
Also, by enabling the negative/positive reversing mode, the film
image sensing mode is set.
[0307] As described above, since the state of the lens system is
added as a determination condition, whether or not a photographic
film image is sensed at the closest distance, i.e., using the film
adapter can be clearly determined. Hence, the camera can be
automatically switched to the still image single shot mode and
negative film image sensing mode without any operation errors.
[0308] With the above-mentioned arrangement, when the film adapter
is attached, the camera is automatically set in the still image
sensing mode, i.e., the negative film image sensing mode, the
operator is relieved from meticulous operations, and the camera can
prevent a negative film image from being captured into a personal
computer in the moving image mode if the operator forgets to do
required operations.
[0309] <15th Embodiment>
[0310] FIG. 38 is a flow chart showing the internal processing of
the camera control circuit 105 in the camera signal processing
circuit 409 according to the 15th embodiment of the present
invention.
[0311] The 15th embodiment has no automatic identification means of
negative/positive film image sensing unlike in the above
embodiments, and when the operator operates the negative/positive
reversing function selection switch 1603 to enable the
negative/positive reversing function, the camera is automatically
switched to the still image single shot mode.
[0312] In this case, this embodiment can be implemented by changing
the processing in the camera control circuit 105 in the camera
signal processing circuit 409. The schematic arrangement of the
overall camera of this embodiment is the same as that shown in FIG.
34, and the internal arrangement of the camera signal processing
circuit 409 is the same as that shown in FIG. 9.
[0313] In FIG. 38, when execution of the processing starts in step
S1901, it is checked in step S1902 if the operator has enabled the
negative/positive reversing function. As described above, the
communication lines 422 and 423 provide ON information of the
negative/positive reversing function.
[0314] If it is determined in step S1902 that the negative/positive
reversing function is ON, the camera is set in the still image
mode, and a negative/positive reversing ON signal is output to the
negative/positive reversing circuit 513 via the signal line 512 to
enable the negative/positive reversing function in step S1905, in
steps S1903 and S1904.
[0315] In this manner, a positive image obtained by converting a
negative film image can be captured in the still image single shot
mode, and can be displayed or recorded.
[0316] If it is determined in step S1902 that the negative/positive
reversing function is OFF, the camera is set in the moving image
mode, and a negative/positive reversing OFF signal is output to the
negative/positive reversing circuit 513 via the signal line 512 to
disable the negative/positive reversing function, in steps S1906
and S1907. In this fashion, a normal moving image sensing mode is
set.
[0317] With the above-mentioned arrangement, even in a camera
without any function of automatically determining negative film
image sensing, the camera is automatically switched to the still
image mode when the negative/positive reversing function is ON.
Hence, the operator is free from cumbersome operations, and the
camera can prevent a negative film image from being captured into a
personal computer in the moving image mode if the operator forgets
to do required operations.
[0318] <16th Embodiment>
[0319] The 16th embodiment provides a photo video camera system
which converts an image projected via a negative or slide film into
a video signal using an image sensing device and records the
converted image on a magnetic tape or the like or outputs it to a
monitor, characterized in that when a film image is sensed in
practice using a film adapter or the like, abrupt changes in video
signal (changes in level of a video signal) caused upon moving a
film (to select another frame) can be minimized.
[0320] In such system, a film is set in a film carrier or the like,
and the film carrier is fixed to the image sensing device using a
film carrier holder or the like. The film set in the film carrier
is illuminated from the back side with a backlight, and an image
projected via the film is sensed by an optical lens and a
solid-state image sensing element mounted on the image sensing
device. The sensed image signal is converted into a video signal by
a signal processing circuit, and the video signal is output. The
system has a function of negative/positive-reversing a video signal
obtained by sensing an image projected via the film.
[0321] In general, the above-mentioned image sensing device has an
exposure control circuit for maintaining a subject (e.g., a
negative film or the like) to be sensed at appropriate brightness
level. When the brightness level of the subject has changed, the
exposure control circuit controls the electronic shutter speed,
iris, AGC, Y-gain, and the like to do exposure control so as to
always obtain an appropriate video signal level.
[0322] However, when the film is fed to move from one frame to
another, if the brightness level of a portion between the two
frames is considerably different from that of the previous frame
(before movement), the brightness level changes considerably for a
certain period as a result of overcorrection of the exposure
control circuit, and an image with very poor quality is displayed
on the monitor. Furthermore, an unwantedly long time is required
due to overcorrection until stable appropriate exposure level can
be obtained for a subject after movement.
[0323] In "normal image sensing", the brightness of a subject
changes with time, but in "film image sensing", changes in
brightness are relatively small. In film image sensing, changes in
brightness of the subject occur only when the film is moved. Hence,
in consideration of the response speed of the exposure control
circuit required for obtaining proper exposure, if the response
speed of the exposure control circuit upon sensing a film image is
set to be lower than that upon sensing a normal subject image, the
user rarely detects unnaturalness in images obtained by film image
sensing.
[0324] In view of the foregoing, in the 16th embodiment, film image
sensing is made detectable by the use of a switch for instructing
start of the film image sensing mode or by arranging an automatic
film determination function. When film image sensing is detected,
the response speed of the exposure control circuit is set to be
lower than that upon normal image sensing, thereby minimizing
abrupt changes in brightness level that result in poor image
quality on the screen of the monitor upon moving the film, and
shortening the time required until appropriate exposure is obtained
after film movement.
[0325] FIG. 39 is a block diagram showing the arrangement of a
photo video camera system of the 16th embodiment.
[0326] In FIG. 39, reference numeral 2001 denotes a backlight unit
for illuminating a negative film from the back side; 2002, a film
holder for fixing a film to a film carrier holder (to be described
below); 2003, a film carrier holder which carries and attaches a
film to the image sensing device; 2004, an image sensing lens;
2005, an iris for adjusting the amount of incoming light; 2006, an
image sensing element such as a CCD or the like; 2007, a correlated
double sampling circuit (CDS circuit) for reducing accumulated
charge noise in an output signal from the image sensing element
2005; 2008, an AGC circuit for adjusting the gain of the sensed
image signal; 2009, an A/D converter for converting the sensed
image signal output from the AGC circuit 2008 into a digital
signal; 2010, a video signal processing circuit for converting the
output signal from the A/D converter 2009 into a video signal;
2011, a gate circuit for gating the sensed image signal output from
the AGC circuit 2008 to divide the image sensing frame into a
plurality of regions and extract an image signal corresponding to
an arbitrary region; 2012, an integrator for integrating the sensed
image signal corresponding to the designated region on the selected
image sensing frame, and obtaining its average light amount; 2013,
a system control circuit (including an exposure control circuit)
which comprises a microcomputer for controlling the overall system;
2014, a negative film mode selection switch; 2016, a D/A converter
for converting an iris control digital signal output from the
system control circuit 2013 into an analog signal; 2017, an iris
driving circuit for driving an iris motor (to be described below);
2018, an iris encoder which comprises, e.g., a Hall element for
detecting the opening amount of the iris, i.e., the aperture value;
2019, an iris motor for driving the iris; 2015, an A/D converter
for converting the output from the iris encoder 2018 into a digital
signal that can be processed by the system control circuit 2013;
2021, a D/A converter for converting an AGC control digital signal
output from the system control circuit 2013 into an analog signal;
2022, an image memory for storing and outputting a digital signal
from the video signal processing circuit 2010 in accordance with a
control signal from the system control circuit 2013; and 2023, a
D/A converter for converting a digital signal output from the image
memory 2022 into an analog signal.
[0327] In the above arrangement, means for controlling exposure
comprises two different control means, i.e., the iris 2005 and AGC
circuit 2008.
[0328] The photo video camera system of the 16th embodiment has the
above-mentioned arrangement, and its operation will be described in
detail below.
[0329] Light emitted by the backlight unit 2001 illuminates one
frame on a film, and light transmitted through the frame is
photoelectrically converted by the image sensing element 2006 via
the image sensing lens 2004. The signal output from the element
2006 is amplified to proper level by the AGC circuit 2008, and the
amplified signal is converted into a video signal by the video
signal processing circuit 2010. The video signal is converted into
an analog signal by the D/A converter 2023 via the image memory
2022, and the analog signal is output.
[0330] At this time, in the above-mentioned arrangement, the means
for exposure control integrates the sensed image signal output from
the AGC circuit 2008 by the integrator 2012, supplies the
integrated signal to the internal exposure control circuit of the
system control circuit 2013, and controls the iris 2005 and the AGC
circuit 2008 using the system control circuit 2013, so that the
input signal level matches a predetermined level set in the
exposure control circuit.
[0331] The integrator 2012 can arbitrarily vary its integral time
although it may be implemented by software or hardware, or a
combination thereof.
[0332] When the system control circuit 2013 detects the film image
sensing mode via the film mode selection switch 2014, reset pulses
which are generated based on a vertical synchronization signal (VD
pulse) input to the system control circuit 2013 and control the
integral time of the integrator are output, e.g., once per three VD
pulses (in this connection, in a normal image sensing mode, one
reset pulse is output in response to one VD pulse), thereby
extending the integral time of the integrator. Since the integral
time of the integrator is prolonged, even when the sensed image
signal level has largely changed instantaneously (upon film
movement), the output from the integrator 2012 changes little, and
the signal level input to the system control circuit 2013 does not
change largely following the output from the integrator 2012.
Consequently, since the output from the exposure control circuit
does not change, overresponse of the iris 2005 controlled by the
exposure control circuit can be suppressed, and changes in
brightness that give rise to poor image quality on the monitor can
be minimized.
[0333] FIGS. 40A and 40B show the outputs from the integrator in
these image sensing modes. FIG. 40A shows the output in the normal
image sensing mode, and FIG. 40B shows the output in the film image
sensing mode.
[0334] In the normal image sensing mode, the integrator integrates
an input signal in response to every VD pulses, and exposure
control is done at the VD pulse periods. On the contrary, in the
film image sensing mode, the reset pulse period of the integrator
is set three times the VD pulse period, and the integrator is reset
at periods 3T, thus prolonging the integral time constant to three
times. With this control, abrupt changes in exposure due to frame
feeding of a film can be prevented. At this time, the reset pulse
timing can be arbitrarily varied as needed by setting a
counter.
[0335] FIG. 41 is a flow chart for explaining the operation for
controlling the integral time of the integrator. This processing is
executed in the microcomputer (system control circuit) 2013. This
control sequence exemplifies operation for controlling the integral
time of the integrator when the film mode selection SW is
pressed.
[0336] In step S2101, it is checked if a vertical synchronization
signal pulse (VD pulse) is at Hi level (note that VD pulses in some
systems may be Low active). It is then checked in step S2102 if the
position of the film mode selection switch is the normal image
sensing mode or film image sensing mode. If the film image sensing
mode is selected, it is checked in step S2103 if a VD counter has
counted a designated number (e.g., 3) of input VD pulses.
[0337] In step S2104, the VD counter for counting the VD pulses is
incremented until it reaches the designated value. Thereafter, the
flow advances to step S2108 to output a current integrated output
voltage value without changing output data.
[0338] If it is determined in step S2103 that the VD counter has
reached the designated value (3), the flow advances to step S2105
to reset the VD counter to zero. In step S2106, data from the
integrator is read. In step S2107, the read data is divided by the
designated value to generate voltage output data.
[0339] Thereafter, exposure control is done by the same processing
as in the normal image sensing mode.
[0340] If it is determined in step S2102 that the film image
sensing mode is not selected, and the normal image sensing mode is
selected, the flow jumps to step S2106 to detect an AE integrated
value, and a driver driving voltage is calculated and output (steps
S2107 and S2108).
[0341] To summarize, when the film image sensing mode is selected,
since a large integral time constant is consequently set not to
update the exposure control integrated value for a predetermined
period, an image with poor quality suffering, e.g., abrupt changes
in brightness on the monitor, can be minimized, and proper exposure
can be quickly obtained after frame movement.
[0342] <17th Embodiment>
[0343] FIG. 42 is a block diagram of an image sensing apparatus
according to the 17th embodiment.
[0344] FIG. 43 is a circuit diagram of an A/D converter shown in
FIG. 42.
[0345] In FIG. 42, reference numeral 3001 denotes a backlight unit
for illuminating a negative film from the back side; 3002, a film
holder for fixing a film to a film carrier holder (to be described
below); 3003, a film carrier holder which carries and attaches a
film to the image sensing device; 3004, an image sensing lens;
3005, an iris for adjusting the amount of incoming light; 3006, an
image sensing element such as a CCD or the like; 3007, a correlated
double sampling circuit (CDS circuit) for reducing accumulated
charge noise in an output signal from the image sensing element
3005; 3008, an AGC circuit for adjusting the gain of a sensed image
signal; 3009, an A/D converter for converting the sensed image
signal output from the AGC circuit 3008 into a digital signal;
3010, a video signal processing circuit (DSP) for converting the
output signal from the A/D converter 3009 into a video signal;
3011, an analog switch for switching a top-side reference voltage
of the A/D converter 3009 in accordance with a control signal from
a system control circuit (microcomputer; to be described below);
3012, a system control circuit which comprises a microcomputer for
controlling the overall system; and 3013, a film image sensing mode
selection switch.
[0346] Reference numeral 3016 denotes a D/A converter for
converting an iris control digital signal output from the system
control circuit 3012 into an analog signal; 3017, an iris driving
circuit for driving an iris motor (to be described below); 3018, an
iris encoder which comprises, e.g., a Hall element for detecting
the opening amount of the iris, i.e., the aperture value; 3019, an
iris motor for driving the iris; and 3020, an A/D converter for
converting the output from the iris encoder 3018 into a digital
signal that can be processed by the system control circuit
3012.
[0347] Reference numeral 3014 denotes an image memory for storing
and outputting a digital signal from the video signal processing
circuit 3010 in accordance with a control signal from the system
control circuit 3012; 3015, a D/A converter for converting a
digital signal output from the image memory 3014 into an analog
signal. In this arrangement, means for controlling exposure is
implemented by controlling two members, i.e., the iris 3005 and AGC
3008.
[0348] The operation will be described below.
[0349] Light emitted by the backlight unit 3001 illuminates one
frame on a film, and light transmitted through the frame is
photoelectrically converted by the image sensing element 3006 via
the image sensing lens 3004. The signal output from the element
3006 is amplified to proper level by the AGC circuit 3008, and the
amplified signal is converted by the A/D converter 3009 into a
digital signal that can be processed by the signal processing
circuit (DSP) 3010. The digital signal is converted into a video
signal by the signal processing circuit 3010, and is then converted
into an analog signal by the D/A converter 3015 via the image
memory 3014. Thereafter, the analog signal is output to a monitor,
recording apparatus, or the like on the output side.
[0350] In the film image sensing mode, the system control circuit
3012 detects switching of the film image sensing mode switch 3013,
and outputs a control signal for instructing switching to the film
image sensing mode to the analog switch 3011 and the like. At this
time, the reference voltage switching operation of the A/D
converter 3009 is done as shown in the circuit diagram of FIG. 43.
Namely, the system control circuit 3012 switches the analog signal
3011 using a control signal for the purpose of setting a reference
voltage V.sub.RT (top side) of the A/D converter 3009 at an optimal
voltage value (V.sub.ref1, V.sub.ref2) in correspondence with the
normal image sensing mode and film image sensing mode.
[0351] For example, let V.sub.ref1 be an optimal reference voltage
(e.g., 3 V) in the normal image sensing mode, and V.sub.ref2 be an
optimal reference voltage (e.g., 2 V) in the film image sensing
mode. In this case, in the film image sensing mode in which the
dynamic range of the A/D converter 3009 can be narrowed down, the
top-side reference voltage is switched to V.sub.ref2 to set a
narrower dynamic range of the A/D converter 3009 than that in the
normal image sensing mode and to improve the S/N ratio, thus
attaining stable, high-quality film image sensing.
[0352] As described above, according to this embodiment, since the
dynamic range of the A/D converter is automatically set to be
narrower than that in the normal image sensing mode in the film
image sensing mode, optimal setting that can most effectively use
the dynamic range of the A/D converter 3009 in the film image
sensing mode can be done, quantization errors (quantization noise)
produced upon A/D conversion can be minimized, and the S/N ratio in
the film image sensing mode is consequently improved, thus allowing
high-quality film image sensing.
[0353] Note that the reference voltages V.sub.ref1 and V.sub.ref2
of the A/D converter 3009 that makes up a signal processing system
switching means are switched via the analog switch 3011.
Alternatively, the microcomputer (system control circuit 3012) may
directly switch these voltages without the intermediacy of the
analog switch 3011. In this case, the need for the analog switch
can be obviated.
[0354] As for the film image sensing mode switch 3013 that makes up
a film image sensing mode selection means, for example, an
operation switch may be arranged to select the film image sensing
mode upon depression of it, and the depression of the switch may be
detected by the system control circuit 3012 to switch the reference
voltage of the A/D converter between V.sub.ref1 and V.sub.ref2, or
attachment of the backlight unit 3001 for film image sensing to the
front surface of the video camera or ON of the backlight unit may
be detected by the system control circuit 3012 to automatically
select an optimal reference voltage.
[0355] As described above, according to the 17th embodiment, the
image sensing apparatus which has the normal video image sensing
mode and film image sensing mode, comprises the film image sensing
mode selection means for detecting film image sensing, and the
signal processing system switching means for switching the
reference voltage of the A/D converter to an optimal voltage in
correspondence with the film image sensing mode and normal image
sensing mode, and controls to narrow down the dynamic range of the
A/D converter in the film image sensing mode. Hence, the SIN ratio
in the film image sensing mode of a negative or positive film can
be improved without influencing image quality in the normal image
sensing mode, and a higher-quality image can be provided.
[0356] <18th Embodiment>
[0357] FIG. 44 is a block diagram showing the arrangement according
to the 18th embodiment of the present invention, and shows the
schematic arrangement of a video camera having a function of
sensing a photographic film image in addition to a normal subject
image.
[0358] In FIG. 44, reference numeral 3101 denotes a film adapter
used for sensing a photographic film image; 3102, a film held by
the adapter 3101; 3103, an imaging lens; 3104, an image sensing
element for photoelectrically converting incoming light via the
lens 3103; 3105, a signal processing circuit for generating
luminance and chrominance signals based on signals generated by the
image sensing element 3104; 3106, a reversing circuit for reversing
a negative image to a positive image; 3107, a switch for selecting
whether or not negative/positive reversing is to be done; 3108, a
noise reduction circuit; 3109, an encoder circuit for converting
the luminance and chrominance signals into a video signal; 3110, a
film adapter detector for detecting attachment of the film adapter
3101; and 3111, a level selector for selecting the noise correction
amount of the noise reduction circuit 3108.
[0359] In the above-mentioned arrangement, the film 3102 is
illuminated by a light source arranged in the film adapter 3101,
and light transmitted through the film 3102 is imaged on the image
sensing element 3104 via the lens 3103. The optical signal that
enters the image sensing element 3104 is photoelectrically
converted by the element 3104, and the signal processing circuit
3105 generates luminance and chrominance signals based on the
signals from the element 3104.
[0360] When the film 3102 to be sensed is a positive film, the
outputs from the signal processing circuit 3105 are directly input
to the noise reduction circuit 3108 by the switch 3107; when the
film 3102 is a negative film, the outputs from the signal
processing circuit 3105 are reversed to those for a positive image
by the reversing circuit 3106, and the reversed signals are input
to the noise reduction circuit 3108. A video signal from which
noise components are reduced by the noise reduction circuit 3108 is
converted into a standard television signal by the encoder circuit
3109, and the converted signal is output.
[0361] The arrangement of the noise reduction circuit 3108 is the
same as that shown in FIG. 3 above. However, a noise reduction
coefficient k is supplied from the level selector 3111 and is
switched between at least two values in synchronism with attachment
of the film adapter 3101.
[0362] The detector 3110 outputs a detection signal when the film
adapter 3101 is attached. FIG. 45 shows the simplest example of the
film adapter detector 3110.
[0363] In FIG. 45, reference numeral 3121 denotes a switch which is
turned on (closed) upon detecting attachment of the film adapter
3101. The switch 3121 has electrical contacts respectively on the
film adapter side and detector main body side, and when the film
adapter 3101 is attached to the video camera, the each other's
electrical contacts come into contact with each other. When the
switch 3121 is OFF (open), the output from the detector equals the
GND level; when the switch 3121 is ON, the output from the detector
equals the power supply level.
[0364] The detection signal output from the film adapter detector
3110 is input to the noise reduction level selector 3111. The noise
reduction level selector 3111 supplies a numerical value
corresponding to the coefficient k given by equation (1) in the
previously mentioned prior art to the noise reduction circuit 3108.
When the film adapter 3101 is not attached, the noise reduction
coefficient k is set at 0.8, and a video signal output
(S.sub.out).sub.n of the n-th frame is given by:
(S.sub.out).sub.n=0.8.multidot.(S.sub.in).sub.n+0.2.multidot.(S.sub.out).s-
ub.n-1(0<k.ltoreq.1) (2)
[0365] More specifically, noise components produced between the
(n-1)-th and n-th frames are improved by -2 dB. The coefficient at
that time is set at a well-balanced numerical value in
consideration of the noise reduction effect and a decrease in
resolution for a subject that moves fast.
[0366] On the other hand, upon detecting attachment of the film
adapter 3101, the noise reduction coefficient k is set at 0.5, and
the video signal output (S.sub.out).sub.n of the n-th frame is
given by:
(S.sub.out).sub.n=0.5.multidot.(S.sub.in).sub.n+0.5.multidot.(S.sub.out).s-
ub.n-1(0<k.ltoreq.1) (3)
[0367] In this case, noise components produced between the (n-1)-th
and n-th frames are improved by -6 dB. The coefficient at that time
is set at a numerical value suitable for sensing a subject that
stands still to give priority to the noise reduction effect rather
than a decrease in resolution for a subject that moves fast.
[0368] As described above, since the noise reduction amount is
changed in correspondence with the presence/absence of the film
adapter 3101, an optimal noise reduction effect can be expected in
correspondence with a normal subject and a photographic film.
[0369] Note that the above-mentioned numerical values are merely
examples, and different correction amounts may be set when
different devices of the image sensing element 3104, signal
processing circuit, and the like are used or when a different noise
reduction scheme is used. The noise correction amount is switched
between two different values. However, the number of values to be
selected may be increased. The frame correlation method has been
described as the noise reduction method. Alternatively, a field
correlation noise reduction method with a field memory, a line
correlation noise reduction method with a line memory, and the like
may be used. Furthermore, the detection method of the film adapter
3101 is not limited to the above-mentioned method, and a manual
switching method may be used.
[0370] <19th Embodiment>
[0371] FIG. 46 is a block diagram showing the arrangement according
to the 19th embodiment of the present invention, and the same
reference numerals in FIG. 46 denote the same parts as in FIG.
44.
[0372] In FIG. 46, reference numeral 3112 denotes a selector for
selecting whether or not negative/positive reversing is to be done.
The switch 3107 selects the outputs from the reversing circuit 3106
in accordance with the output from the selector 3112. Reference
numeral 3113 denotes a coefficient output unit for outputting a
noise reduction coefficient a; 3114, a coefficient output unit for
outputting a noise reduction coefficient b; and 3115, a switch for
switching the noise reduction coefficients in synchronism with
reversing of the reversing circuit 3106 depending on the output
from the selector 3112.
[0373] The selector 3112 can select one of a non-reversing mode and
reversing mode. The switch 3115 outputs the coefficient a from the
coefficient output unit 3113 in the non-reversing mode, or outputs
the coefficient b from the coefficient output unit 3114 in the
reversing mode.
[0374] In the above-mentioned arrangement, when a normal subject
image is to be sensed, the subject image is formed on the image
sensing element 3104 via the lens 3103. The optical signal that
enters the image sensing element 3104 is photoelectrically
converted by the element 3104, and the signal processing circuit
3105 generates luminance and chrominance signals based on the
signals from the element 3104. At this time, by selecting the
non-reversing mode by the selector 3112, a video signal is directly
input to the noise reduction circuit 3108.
[0375] The arrangement of the noise reduction circuit 3108 is the
same as that shown in FIG. 45, and its noise reduction coefficient
k is supplied from the coefficient output unit 3113 as the
coefficient a. A video signal from which noise components are
reduced by the noise reduction circuit 3108 is converted into a
standard television signal by the encoder circuit 3109, and the
converted signal is output.
[0376] When the film 3102 is to be sensed by attaching the film
adapter 3101, it is illuminated by a light source. Light
transmitted through the film 3102 is imaged on the image sensing
element 3104 by the lens 3103. The optical signal that enters the
image sensing element 3104 is photoelectrically converted by the
element 3104, and the signal processing circuit 3105 generates
luminance and chrominance signals based on the signals from the
element 3104.
[0377] When the film 3102 to be sensed is a negative film, the
selector 3112 selects the reversing mode, and the switch 3107
selects the output from the reversing circuit 3106. As a result,
signals converted into those for a positive image by the reversing
circuit 3106 are input to the noise reduction circuit 3108. At this
time, the noise reduction coefficient k is supplied from the
coefficient output unit 3114 as the coefficient b. A video signal
from which noise components are reduced by the noise reduction
circuit 3108 is converted into a standard television signal by the
encoder circuit 3109, and the converted signal is output.
[0378] The noise reduction coefficient k output from the
coefficient output unit 3113 in the non-reversing mode is set at
0.8, and the video signal output (S.sub.out).sub.n of the n-th
frame at that time is given by equation (2) above as in the 18th
embodiment shown in FIG. 44. That is, noise components produced
between the (n-1)-th and n-th frames are improved by -2 dB. The
coefficient at that time is set at a well-balanced numerical value
in consideration of the noise reduction effect and a decrease in
resolution for a subject that moves fast.
[0379] On the other hand, in the reversing mode, the noise
reduction coefficient output from the coefficient output unit 3114
is set at 0.5, and the video signal output (S.sub.out).sub.n of the
n-th frame at that time is given by equation (3) above as in the
18th embodiment. In other words, noise components produced between
the (n-1)-th and n-th frames are improved by -6 dB. The coefficient
at that time is set at a numerical value suitable for sensing a
subject that stands still while placing an importance on the noise
reduction effect rather than a decrease in resolution for a subject
that moves fast.
[0380] As described above, since the noise reduction amount is
changed between the non-reversing mode and reversing mode, an
optimal noise reduction effect can be obtained in correspondence
with a normal subject image and a negative film image.
[0381] Note that the above-mentioned numerical values are merely
examples, and different correction amounts may be set when
different devices of the image sensing element 3104, signal
processing circuit, and the like are used or when a different noise
reduction scheme is used. The noise correction amount is switched
between two different values. However, the number of values to be
selected may be increased. The frame correlation method has been
described as the noise reduction method but other methods may be
used. The selector 3112 may be switched manually or a negative film
may be automatically detected.
* * * * *