U.S. patent application number 12/929191 was filed with the patent office on 2011-05-05 for electronic camera that displays information representative of its selected mode.
This patent application is currently assigned to NIKON CORPORATION. Invention is credited to Masahiro Juen.
Application Number | 20110102614 12/929191 |
Document ID | / |
Family ID | 17250016 |
Filed Date | 2011-05-05 |
United States Patent
Application |
20110102614 |
Kind Code |
A1 |
Juen; Masahiro |
May 5, 2011 |
Electronic camera that displays information representative of its
selected mode
Abstract
An electronic camera is used with a display screen and includes
an imaging device, a pixel density converter, a moving image
recording device and a still image recording device. The imaging
device images an object and converts the imaged object to image
information. The pixel density converter converts the image
information converted by the imaging device to a pixel density
suitable for a scan format of the display screen. The moving image
recording device successively retrieves the image information from
the pixel density converter and records the image information in
the recording medium as a series of moving images. The still image
recording device retrieves the image information converted by the
imaging device and records the image information in the recording
medium as a still image.
Inventors: |
Juen; Masahiro;
(Kanagawa-ken, JP) |
Assignee: |
NIKON CORPORATION
Tokyo
JP
|
Family ID: |
17250016 |
Appl. No.: |
12/929191 |
Filed: |
January 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11075333 |
Mar 9, 2005 |
7903162 |
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12929191 |
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09951417 |
Sep 14, 2001 |
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11075333 |
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08937805 |
Sep 25, 1997 |
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09951417 |
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60040922 |
Mar 27, 1997 |
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Current U.S.
Class: |
348/220.1 ;
348/E5.024 |
Current CPC
Class: |
H04N 2101/00 20130101;
H04N 5/232935 20180801; H04N 1/2112 20130101; H04N 9/7921 20130101;
H04N 5/23293 20130101; H04N 5/9261 20130101; H04N 1/212 20130101;
H04N 5/232939 20180801; H04N 5/85 20130101; H04N 1/0044 20130101;
H04N 5/772 20130101 |
Class at
Publication: |
348/220.1 ;
348/E05.024 |
International
Class: |
H04N 5/225 20060101
H04N005/225 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 1996 |
JP |
08-253343 |
Claims
1. (canceled)
2. A digital electronic device comprising: an imaging device that
generates successive image signals; an analog to digital converter
that converts an output of the imaging device to digital image
signals; a compression unit that performs a first compression for
digital moving images and a second compression, different from the
first compression, for digital still images; a mode selector that
selects one of a moving image recording mode in which recording of
moving images can be performed and a still image recording mode in
which recording of still images can be performed; a memory unit; a
display that includes a touch panel having an operation button,
wherein the operation button includes an operation button for
performing a predetermined function; a recording unit that records
the compressed digital moving images and the compressed digital
still images into the memory unit; and a control unit electrically
connected to the compression unit, the mode selector, the display
and the recording unit, the control unit causing the display to
simultaneously display either of the moving or still images and
information representative of a mode selected by the mode selector;
wherein a displayed position of the operation button for performing
the predetermined function on the touch panel when the moving image
recording mode is selected is the same as a displayed position of
the operation button for performing the predetermined function on
the touch panel when the still image recording mode is
selected.
3. A digital electronic device according to claim 2, further
comprising a housing, wherein the display and the mode selector are
disposed on a same surface of the housing.
4. A digital electronic device according to claim 2, wherein the
first compression is MPEG and the second compression is JPEG.
5. A digital electronic device according to claim 2, wherein a
pixel number of a frame of the recorded moving images is lower than
a pixel number of a frame of the recorded still images.
6. A digital electronic device according to claim 2, wherein the
control unit causes the display to display the recorded moving
images and the recorded still images.
7. A digital electronic device according to claim 2, wherein the
control unit causes the display to display the moving or still
image at a first display area of the display and to display the
information representative of the mode selected by the mode
selector at a second display area of the display, the second
display area being different from the first display area.
8. A digital electronic device according to claim 2, wherein the
control unit causes the display to simultaneously display a screen
for a recording operation for recording images and a screen for an
editing operation.
9. A digital electronic device according to claim 2, wherein the
operation button for performing the predetermined function is an
operation button for initiating recording of the moving image on
the touch panel when the moving image recording mode is selected,
and is an operation button for initiating recording of the still
image on the touch panel when the still image recording mode is
selected.
10. A digital electronic device according to claim 2, wherein the
operation button for performing the predetermined function is a
mode change operation button for changing a mode between the moving
image recording mode and the still image recording mode.
Description
[0001] This is a Continuation of Application No. 11,075,333 filed
Mar. 9, 2005, which is a Continuation of application Ser. No.
09/951,417 filed Sep. 14, 2001, which is a Continuation of
application Ser. No. 08/937,805 filed Sep. 25, 1997, which is a
Non-Provisional of U.S. Provisional Application No. 60/040,922
filed Mar. 27, 1997. The disclosures of the previous applications
are hereby incorporated by reference herein in their entirety.
INCORPORATED BY REFERENCE
[0002] The disclosure of the following priority application is
herein incorporated by reference: Japanese Application No. 8-253343
filed on Sep. 25, 1996.
BACKGROUND OF THE INVENTION
[0003] 1. Field of Invention
[0004] This invention relates to an electronic camera that records
both moving images and still images.
[0005] 2. Description of Related Art
[0006] In recent years, electronic cameras have been developed that
photoelectrically convert an object to image information of a
moving image, execute image compression such as high efficiency
coding on that image information, and record the compressed image
information in a recording medium.
[0007] As representative of this kind of electronic camera, digital
video (DV) cameras are known. In a DV camera, a still image
recording mode is provided and it is possible to record one frame
of a still image and combine it with a sound signal over a number
of seconds.
[0008] In this conventional example, a still image is recorded as a
snapshot corresponding to one frame of a moving image. However, in
this conventional example, a still image is recorded in the image
quality of one frame of a moving image (for example, in the NTSC
method of a YC component, excluding the retracing period), the
vertical degree of resolution is 480 lines and the horizontal
degree of resolution is 500 lines.
SUMMARY OF THE INVENTION
[0009] Therefore, an object of the present invention is to provide
an electronic camera that can record a still image at a high image
quality.
[0010] Another object of the present invention is to provide an
electronic camera that can image still objects or subjects at will,
even while recording a moving object or subject.
[0011] Yet another object of the present invention is to provide an
electronic camera that is designed to share the recording process
for still images and the recording process for moving images.
[0012] A still further object of the present invention is to
provide an electronic camera that can record still images at a high
image quality, while designing the electronic camera so that it is
made to share the recording process for still images and the
recording process for moving images.
[0013] Another object of the present invention is to provide an
electronic camera that can image still images at will, even while
recording a moving image.
[0014] Still further, another object of the present invention is to
provide an electronic camera that can enhance the operational
quality relating to recording changeover between still images and
moving images.
[0015] Accordingly, an electronic camera is used with a display
screen and includes imaging means, pixel density conversion means,
a recording medium, moving image recording means and still image
recording means. The imaging means images an object and converts
the imaged object to image information. The pixel density
conversion means converts the image information converted by the
imaging means to a pixel density suitable for a scan format of the
display screen. The moving image recording means successively
retrieves the image information from the pixel density conversion
means and records the image information in the recording medium as
a series of moving images. The still image recording means
retrieves the image information converted by the imaging means and
records the image information in the recording medium as a still
image.
[0016] The imaging means includes an imaging pixel number and the
scan format includes a scan pixel number wherein the imaging pixel
number is larger than the scan pixel number. The pixel density
conversion means reduces the image information converted by the
imaging means to a pixel density that is suitable for the scan
format. Preferably, the electronic camera of the present invention
includes buffer means that temporarily stores the image information
from the imaging means upon receipt of a command for recording
still images when the command for recording is given from an
external source during a recording period of the moving image
recording means. The still image recording means waits until
completion of recording by the moving image recording means and
records the image information stored in the buffer means in the
recording medium. Preferably, the moving image recording means and
the still image recording means share a coding conversion component
for executing high efficiency coding within a field or frame on the
image information that has been retrieved.
[0017] It is preferable that the electronic camera of the present
invention include a recording switch and a changeover switch. The
recording switch receives a recording command from an external
source. The changeover switch which receives the recording command
from the recording switch can be used either for the moving image
recording means or for the still image recording means in response
to a mode changeover command from an external source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention will be described in conjunction with the
following drawings in which like reference numerals designate like
elements and wherein:
[0019] FIG. 1 is a block diagram depicting an exemplary embodiment
of an electronic camera of the present invention;
[0020] FIG. 2 is a block diagram depicting another exemplary
embodiment of the electronic camera of the present invention;
[0021] FIG. 3 is a block diagram depicting another exemplary
embodiment of the electronic camera of the present invention;
[0022] FIG. 4 is a block diagram depicting another exemplary
embodiment of the electronic camera of the present invention;
[0023] FIG. 5 is a block diagram depicting another exemplary
embodiment of the electronic camera of the present invention;
[0024] FIG. 6 is a block diagram depicting another exemplary
embodiment of the electronic camera of the present invention;
[0025] FIG. 7 is a block diagram of a first preferred embodiment of
the electronic camera of the present invention;
[0026] FIG. 8 is a perspective view of the first preferred
embodiment of the electronic camera of the present invention;
[0027] FIG. 9 is a block diagram illustrating a structure of a
coding conversion component;
[0028] FIG. 10 is flowchart depicting partial operation of the
first preferred embodiment of the electronic camera of the present
invention;
[0029] FIG. 11 is flowchart depicting partial operation of the
first preferred embodiment of the electronic camera of the present
invention;
[0030] FIG. 12 is a block diagram illustrating a second preferred
embodiment of the electronic camera of the present invention;
[0031] FIG. 13 is a flowchart depicting partial operation of the
second preferred embodiment of the electronic camera of the present
invention;
[0032] FIG. 14 is a flowchart depicting partial operation of the
second preferred embodiment of the electronic camera of the present
invention;
[0033] FIG. 15 is a first example display shown on a display screen
of the electronic camera of the present invention;
[0034] FIG. 16 is a second example display shown on the display
screen of the electronic camera of the present invention; and
[0035] FIG. 17 is a third example display shown on the display
screen of the electronic camera of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] FIG. 1 is a block diagram of an exemplary embodiment of the
present invention.
[0037] In FIG. 1, an electronic camera 100 includes an imaging
means 1 that images an object or living subject (hereinafter
referred to as "object") and converts an image thereof to image
information. A pixel density conversion means 2 converts the image
information converted by the imaging means 1 to a pixel density
suitable for a scan format of a display screen. A moving image
recording means 3 successively retrieves the image information in
which the pixel density has been converted by the pixel density
conversion means 2 and records it in a recording medium R as a
series of moving images. A still image recording means 4 retrieves
image information converted by the imaging means 1 to record it in
the recording medium R as a still image.
[0038] When performing the recording of a moving image, first, the
image information from the imaging means 1 is converted via the
pixel density conversion means 2 to a pixel density that is
compatible with a scan format of a display screen 25 (shown in FIG.
8). Although not by way of limitation, the display screen 25 can be
an electronic viewfinder, a monitor screen attached to the case of
the electronic camera, a device displaying the playback of the
image information from the recording medium R (for example, a
television or a computer monitor) or an image display device
connected to an image output terminal of the electronic camera.
[0039] The moving image recording means 3 retrieves the image
information after pixel density conversion, creates a moving image,
and records the moving image in the recording medium R. On the
other hand, when performing the recording of a still image, the
image information is not retrieved by the pixel density conversion
means 2 but rather by the still image recording means 4. The still
image recording means 4 records the image information in the
recording medium R.
[0040] The imaging means 1 has a pixel number that is larger than
the pixel number of the scan format. Accordingly, the pixel density
conversion means 2 reduces the image information converted by the
imaging means 1 to a pixel density that is suitable for the scan
format. Therefore, the image information is created in the imaging
means 1, in a pixel density that is higher than the pixel density
of the scan format.
[0041] At this time, when a moving image is recorded, the pixel
density conversion means 2 reduces the density of the image
information that initially has a high pixel density to a pixel
density appropriate to the scan format. The moving image recording
means 3 records the image information after this conversion to the
recording medium R. On the other hand, when the still image is
recorded, the still image recording means 4 records the image
information in a state in which the pixel density is high in the
recording medium R as a still image.
[0042] FIG. 2 is a block diagram of another exemplary embodiment of
the present invention.
[0043] In FIG. 2, the electronic camera 100 is equipped with a
buffer means 5 that temporarily stores the image information from
the imaging means 1 upon receipt of a command for recording still
images when the command for recording is given from an external
source during a recording period of the moving image recording
means 3. The still image recording means 4 waits for completion of
recording by the moving image recording means 3 and records the
image information stored in the buffer means 5 in the recording
medium R.
[0044] When the still image recording command is supplied from an
external source during the moving image recording period, the
buffer means 5 temporarily stores the image information from the
imaging means 1. The still image recording means 4 waits for
completion of recording of the moving image recording means 3 and
records the image information stored in the buffer means in the
recording medium R. By doing this, it is possible to reliably image
snapshots even during recording of moving images.
[0045] FIG. 3 is a block diagram of another exemplary embodiment of
the present invention.
[0046] In FIG. 3, the moving image recording means 3 and the still
image recording means 4 share a coding conversion component 6 for
executing high efficiency coding within a field or frame on the
image information that has been retrieved.
[0047] The moving image recording means 3 and the still image
recording means 4 share the coding conversion component 6 that
performs high efficiency coding (i.e., compression) of the image
information. For example, in a moving image coding conversion
section, processes are performed such as a DCT (Discreet Cosine
Transform) calculation, predictions between the frames, variable
length coding and the like. On the other hand, in a still image
coding conversion processes are performed such as a DCT
calculation, variable length coding and the like. Therefore, the
processes within a frame or field in the moving image coding
conversion section are the same as the processes for the still
image coding conversion section. It is possible to simplify the
calculation process algorithms, the circuit structure of the
electronic camera and the like by providing the coding conversion
component 6 to perform these common processes.
[0048] FIG. 4 is a block diagram of another exemplary embodiment of
the present invention.
[0049] In FIG. 4, the imaging means 1 images the object and
converts it to image information. An image compression means 7,
which can be any conventional image compression device known in the
art, compresses image information imaged by the imaging means 1.
The moving image recording means 3 successively retrieves the image
information compressed by the image compression means 7 to record
it in the recording medium R as moving images. The still image
recording means 4 retrieves the image information compressed by the
image compression means 7 to record it in the recording medium R as
a still image. A compression rate changing means 8 which can be any
conventional compression rate changing device known in the art
increases the compression rate of the image compression means 7
during recording of the moving image recording means 3 and lowers
the compression rate of the image compression means 7 during
recording of the still image recording means 4. The compression
rate is the ratio of the amount of information before compression
to the amount of information that remains after compression. The
compression rate of the image compression means 7 is raised during
recording of a moving image, and the compression rate is lowered
during recording of still images.
[0050] FIG. 5 is a block diagram of another exemplary embodiment of
the present invention.
[0051] In FIG. 5, the electronic camera is equipped with the buffer
means 5 that temporarily stores the image information from the
imaging means 1 upon receipt of the command for recording still
images when the command for recording is given from the external
source during the recording period of the moving image recording
means 3. The image compression means 7 waits for completion of
recording by the moving image recording means 3 and compresses the
image information stored in the buffer means 5. The still image
recording means 4 retrieves the image information from the buffer
means 5 that has been compressed by the image compression means 7
and records it in the recording medium R as a still image.
[0052] When the still image recording command is externally
supplied during the moving image recording period, the buffer means
5 temporarily stores image information from the imaging means 1. In
this state, the image compression means 7 waits for the completion
of recording of the moving image recording means 3 and compresses
the image information stored in the buffet means 5 (using the still
image compression rate supplied by compression rate changing means
8). The still image recording means 4 records the image information
compressed in this manner in the recording medium R.
[0053] FIG. 6 is a block diagram of another exemplary embodiment of
the present invention.
[0054] In FIG. 6, the electronic camera includes a recording switch
10a that receives a recording command from the external source and
a changeover switch 10b in which the recording command received by
the recording switch 10a can be used either for the moving image
recording means 3 or for the still image recording means in
response to a mode changeover command from the external source. As
a result of changing over by the changeover switch 10b, the
recording switch 10a has a dual use as the switch operating the
still image recording means 4 and the moving image recording means
3.
[0055] The preferred embodiments of the electronic camera of the
present invention are described below based on the drawings.
[0056] FIG. 7 is a block diagram of a first preferred embodiment of
the present invention. FIG. 8 shows an outer appearance of the
first embodiment of the present invention.
[0057] In FIGS. 7 and 8, on a side surface of a main body 11 of the
electronic camera, a camera part 11a is installed so that it freely
rotates, and a photographic lens 12, that performs image resolution
of the object image, is attached to the camera part 11a.
[0058] Light passing through the photographic lens 12 is refracted
within the camera part 11a, and received by a photoreceptor surface
of an imaging element 13, which is composed of a CCD image sensor.
For example, the number of pixels of the imaging element 13 is 960
in length.times.1280 in width, which is twice the degrees in both
length and width of the effective resolution in a NTSC method.
[0059] The photoelectric output of the imaging element 13 is
connected to a picture image signal processor 15 that performs
white balance adjustment, gamma correction, or the like via an A/D
converter 14.
[0060] The image information of the picture image signal processor
15 is input to an image density converter 16 and a memory I/O
component 17.
[0061] The image density converter 16 performs conversion of the
pixel density by executing interpolation, dividing into identical
blocks, thinning, and the like, to the pixel value of the image
information.
[0062] The memory I/O component 17 controls input and output of the
image information to a system bus 19 of a microprocessor 18.
[0063] The output of the image density converter 16 and the memory
I/O component 17 is input to a coding conversion component 21 via
an interface component 20.
[0064] The interface component 20 communicates with the
microprocessor 18 via the system bus 19.
[0065] To the system bus 19, a memory 22, disk drive part 23, the
liquid crystal display screen 25, and a touch panel 25a are
respectively connected.
[0066] The memory 22, in conjunction with being used in the
information processing of the microprocessor 18, is also used as a
buffer for temporarily storing image information.
[0067] A magnetooptical recording medium 24 is externally installed
to a disk drive component 23.
[0068] The liquid crystal display screen 25 is arranged on the rear
surface side of the main body 11, and the touch panel 25a is
provided over the surface of the liquid crystal display screen
25.
[0069] An image recording button 26, and a mode button 27 are
arranged on the main body 11 and are connected to the
microprocessor 18.
[0070] FIG. 9 is a block diagram describing the structure of the
coding conversion component 21.
[0071] In FIG. 9, the image information input via the interface
component 20 (FIG. 7) is provided to a pixel arranging component 31
and a moving vector detection component 33. The output of the pixel
arranging component 31 is connected respectively to a first input
of a subtracting device 32 and a first input of a first switch
34.
[0072] The output of the subtracting device 32 is connected to a
second input of the first switch 34, and the output of the first
switch 34 is connected to a quantizer 36 via a DCT calculator 35.
The output of the quantizer 36 is connected to a reverse quantizer
37 and a variable length coder 38. The output of the variable
length coder 38 is connected to a first input of the data
multiplexer 39.
[0073] On the other hand, the output of the reverse quantizer 37 is
connected to a first input of an adding component 41 via a inverse
DCT calculator 40. The output of adding component 41 is connected
to an image memory 42 having the storage capacity of a frame of
image data. The image information accumulated in the image memory
42 is input to a second input of the moving vector detection
component 33 and a first input of a motion compensation component
43.
[0074] The output of the moving vector detection component 33, in
conjunction with being connected to a second input of the motion
compensation component 43, is connected to a second input of the
data multiplexer 39 via a second switch 45.
[0075] The prediction-between-the-frames result output from the
motion compensation component 43, in conjunction with being input
to a second input of the subtracting device 32, is input to a
second input of the adding component 41 via a third switch 44.
[0076] On the other hand, the control output of the compression
mode controller 46 connected to the system bus 19, is connected to
the pixel arranging part 31, the first switch 34, the third switch
44, the second switch 45, the control header generator 47, and the
like.
[0077] The input/output of the control header generator are
connected individually to the quantizer 36, the variable length
coder 38 and to a third input of the data multiplexer 39.
[0078] The output of the data multiplexer 39 is connected to the
system bus 19.
[0079] With respect to FIGS. 1-6, the imaging means 1 includes the
photographic lens 12, the imaging element 13, the A/D converter 14,
and the picture image signal processor 15. The pixel density
conversion means 2 includes the image density converter 16. The
moving image recording means 3 includes the coding conversion
component 21, the disk drive component 23 and a command controlling
the recording operation of the moving image of the microprocessor
18. The still image recording means 4 includes the coding
conversion component 21, the disk drive component 23, and a command
controlling the recording operation of the still image of the
microprocessor 18. The buffer means 5 includes the image
compression means 7 and the memory 22. The coding conversion
component 6 includes the pixel arranging component 31, the DCT
calculator 35, the quantizer 36, the variable length coder 38, and
the data multiplexer 39. The recording switch 10a includes the
image recording button 26 and the changeover switch 10b corresponds
to the mode button 27. The various means of FIGS. 1-6 are not
limited to these structures, which only relate to one possible
implementation of the invention.
[0080] FIG. 10 and FIG. 11 are flowcharts that describe the
operation of the first embodiment. The operation of the first
embodiment is described below using these figures.
[0081] First, when the mode button 27 is pressed (FIG. 10 S1), the
microprocessor 18 determines that it is the still mode that
performs still image photography, and after the liquid crystal
display screen 25 is changed to the display used for the still
mode, the process moves to the step S20, which will be explained
later.
[0082] When the mode button 27 has not been pressed (FIG. 10 S1),
the microprocessor 18 determines that it is the movie mode that
performs photography of moving images.
[0083] In the movie mode, when the image recording button 26 has
been pressed (FIG. 10 S2), the microprocessor 18 sets the coding
conversion component 21 as appropriate for the movie mode (FIG. 10
S3). That is, the microprocessor 18 sets the output selection of
the first switch 34 to the first input side via a compression mode
controller 46, and, specifically, the third switch 44 and the
second switch 45 are defined in an ON state.
[0084] At this time, the image density converter 16 successively
retrieves image information, that has been digitized, from the
camera part 11a (FIG. 10 S4). The image density converter 16
divides the image information into 2.times.2 pixel blocks,
respectively, and reduces the density to a pixel density of
480.times.640 pixels (FIG. 10 S5). At this time, the pixel density
in the vertical direction becomes equivalent to 480, after
excluding the retrace time, from the number of scanning lines, 525,
in the vertical direction in the NTSC method.
[0085] The microprocessor 18 changes over the output selection of
the interface component 20, and transmits the output of the image
density converter 16 to the coding conversion component 21. Within
the coding conversion part 21, high efficiency coding corresponding
to the moving image is executed in the following manner:
[0086] First, in the pixel arranging component 31, the image pixels
are divided into 8.times.8 pixel blocks and are output. The
subtracting device 32 writes in these pixel blocks and calculates
the differential, i.e., the prediction error between the pixel
blocks and the pixel blocks predicted between the frames in the
motion compensation component 43 (FIG. 10 S6).
[0087] The DCT calculator 35 converts the 8.times.8 pixel value
into 64 individual DCT coefficients by executing a discrete cosine
transform for this prediction error. The quantizer 36 quantizes
these DCT coefficients according to a fixed quantizing table.
[0088] The variable length coder 38 converts the quantized DCT
coefficients to a variable code such as a Huffman code, and outputs
it to the data multiplexer 39 (FIG. 10 S7).
[0089] On the other hand, in the reverse quantizer 37, the reverse
DCT calculator 40 and the adding part 41, decoding of the image
information is performed based on the quantized DCT coefficient.
The decoded image information is stored successively in the image
memory 42.
[0090] For example, the compression/decompression process can be
performed according to the JPEG standards for still images, and
according to the MPEG standards for moving images. Other
compression techniques can also be used with the invention.
[0091] The moving vector detection component 33 compares the former
decoded image information stored in the image memory 42 with the
current image information and detects the moving vector based on a
rigid body hypothesis of the object. A moving vector detected in
this manner, in conjunction with being transferred to the data
multiplexer 39, is used in prediction between frames in the motion
compensation component 43.
[0092] On the other hand, in a control header generator 47 (FIG.
9), header information is generated that includes a quantizing
table, a Huffman coding table, and the like, and is transmitted to
the data multiplexer 39. In the data multiplexer 39, data
transmitted from the variable length coder 38, the moving vector
detection component 33 and the control header generator 47 is
multiplied and output to the system bus 19. The disk drive
component 23 successively retrieves this data, and records it in
the magnetooptical recording medium 24 (FIG. 10 S8).
[0093] By repeating the recording operation described above until
the image recording button 26 has again been pressed (FIG. 10 S9),
a moving-image image file is created on the magnetooptical
recording medium 24.
[0094] On the other hand, when the mode button 27 and the image
recording button 26 have been simultaneously or successively
pressed during the recording period of the moving image (FIG. 10
S10, S11), the microprocessor 18 determines that there has been an
external command for still photography, and one frame of image
information is temporarily stored in the following manner:
[0095] First, it is determined whether one frame of image
information can be housed in the memory 22 to which it is
temporarily stored (FIG. 10 S12). Then, when the amount of free
memory capacity is determined insufficient, a warning message is
displayed on the liquid crystal display screen 25 (FIG. 10 S13),
the still mode is abandoned (FIG. 10 S15) and the recording
operation of moving images continues as is.
[0096] On the other hand, when there is sufficient free memory
capacity, the memory I/O component 17 retrieves one frame of image
information from the camera part 11a, and temporarily stores this
still image in the memory 22 via the system bus 19 (FIG. 10 S14).
During this temporary storage operation, the recording operation of
the moving image continues as is. Moreover, the temporary storage
of the still image can be performed for a plurality of frames,
limited only by the capacity of the memory 22.
[0097] During the recording operation for this kind of moving
image, the moving image recording operation is completed when the
image recording button 26 has again been pressed during step S9. At
this time, the microprocessor 18, during the recording operation of
the moving image, determines whether the aforesaid still image
temporary storage operation has been performed (FIG. 10 S16).
[0098] At this time, when the still image temporary storage
operation has not been performed, the microprocessor 18 returns to
step S1 and repeats the above-described operation. On the other
hand, when the still image temporary storage operation has been
performed, the microprocessor 18 reads out the still image from the
memory 22 (FIG. 11 S17), moves to the operation in step S22, which
is described later, and executes recording of the still image.
[0099] Also, the microprocessor 18 moves to step S20 when the mode
button 27 is pressed in step S1 and waits until the image recording
button 26 is pressed. In this state, when the image recording
button 26 is pressed (FIG. 11 S20), the microprocessor 18 retrieves
one frame of a still image from the camera part 11a via the memory
I/O component 17. This still image is stored for a time in the
memory 22 or the like.
[0100] Next, the microprocessor 18 sets the coding conversion
component 21 in the still mode for still image compression (FIG. 11
S22). That is, the microprocessor sets the output selection of the
first switch 34 to the second input side via the compression mode
controller 46, and the third switch 44 and second switch 45 are
defined as in the OFF state. Further, the pixel arranging component
31, by re-using the image memory 42 for prediction between the
frames, stores the entire still image that has a high pixel density
(FIG. 11 S23).
[0101] Next, in the pixel arranging component 31, the image
information of the still image is divided into 8.times.8 pixel
blocks and output. The DCT calculator 35 converts the 8.times.8
pixel block into 64 individual DCT coefficients by executing a
discrete cosine transform on this pixel block. The quantizer 36
quantizes these DCT coefficients according to a fixed quantizing
table. The variable length coder 38 converts the quantized DCT
coefficients into a variable length code such as a Huffman code and
outputs it to the data multiplexer 39 (FIG. 11 S24).
[0102] On the other hand, in the control header generator 47,
header information is generated including a quantizing table and a
Huffman coding table. This header information is transmitted to the
data multiplexer 39. In the data multiplexer 39, the data
transmitted from the variable length coder 38 and the control
header generator 47 is multiplied and output to the system bus 19.
The disk drive component 23 successively retrieves this data and
records it as an image file of a still image in the magnetooptical
recording medium 24 (FIG. 11 S25).
[0103] Then, the microprocessor 18 investigates whether any other
still images that have been given temporary storage in the memory
22 yet remains (FIG. 11 S26). When a still image yet remains in the
memory 22, the microprocessor 18 returns to step S17 and performs
retrieval of image information. On the other hand, when still
images, are no longer there, the microprocessor 18 returns to step
S1.
[0104] As described above, in the first embodiment, the imaging
element 13, the A/D converter 14, and the picture image signal
processor 15 can share the still image and moving image recording
processes. Further, by changing over the pixel density via the
image density converter 16, it is possible to record a still image
having a higher image quality than that of a moving image, while
recording the moving image in an image density matching the scan
format.
[0105] Furthermore, because the still image has temporarily been
given temporary storage in the memory 22, it is possible to
reliably photograph a still image even during the recording period
of the moving image.
[0106] Further, because a common component of the coding conversion
component 21 has a dual use as a still image/moving image coding
process, the structure of the electronic camera, the calculation
process algorithm or the like can be made to be more concise.
Furthermore, by pressing the mode button 27, it is possible for the
image recording button 26 to have a dual use as a still
image/moving image recording switch.
[0107] Next, a second preferred embodiment of the present invention
is described. FIG. 12 is a block diagram of the second preferred
embodiment of the present invention. A feature of the structure of
the second embodiment is that the image density converter 16 (FIG.
7) is omitted. Moreover, the structural elements that are the same
as the structural elements shown in FIGS. 7-9 are denoted with the
same reference numbers and any repetitive explanation here is
omitted.
[0108] With respect to FIGS. 4 and 5, the imaging means 1 includes
the photographic lens 12, the imaging element 13, the A/D converter
14, and the picture image signal processor 15. The moving image
recording means 3 includes the disk drive component 23 and the
command controlling recording of the moving image of the
microprocessor 18. The still image recording means 4 includes the
disk drive component 23 and the command controlling the recording
of the still image of the microprocessor 18. The image compression
means 7 includes the coding conversion component 21. A compression
rate changing means 8 shown in FIG. 4 includes the compression mode
controller 46, the control header generator 47 and the command
changing the quantizing table of the microprocessor 18. The buffer
means 5 includes the memory I/O component 17 and the memory 22.
[0109] FIGS. 13 and 14 are flowcharts describing the operation of
the second embodiment of the present invention. The main features
in the operation of the second embodiment of the present invention
are the following two points:
[0110] 1) When recording a moving image, the control header
generator 47 generally changes each value of the quantizing table
to a greater value (FIG. 13 S5); and
[0111] 2) When recording a still image, the control header
generator 47 generally changes each value of the quantizing table
to a smaller value (FIG. 14 S22a).
[0112] Due to this operation, in the second embodiment of the
present invention, the image compression rate for still images is
suppressed so that it is low, and the inferiority of quality during
playback of the still image is reduced. Further, with regard to a
moving image, it is possible for the image compression rate to
become high, and to suppress the file capacity of the moving image
so that it is low. Furthermore, because the memory temporarily
gives temporary storage to the still image, it is possible to
reliably record still images even during the moving image recording
period.
[0113] Moreover, although in the embodiment described above, manual
image recording operations are received by the image recording
button 26 and the mode button 27 provided on the main body 11, the
structure of the present invention is not limited to this. For
example, it is also possible to display an operation screen (i.e.,
a user interface screen), such as is shown in FIGS. 15-17, that is
displayed on the liquid crystal display screen 25, and to receive
manual operations via the touch panel 25a. In this case, it is
optimum, when the mode buttons 27 shown in FIGS. 16 and 17 are each
respectively pressed, to display these screens as mutually
interchangeable.
[0114] Further, in the embodiments described above, although the
magnetooptical recording medium 24 has been used as the recording
medium, the present invention is not limited to specific materials
or structural form of recording medium; it is acceptable to use any
recording medium that can record image information. For example, an
optical recording medium, a magnetic recording medium, or a memory
card may be used.
[0115] Furthermore, in the embodiments described above, although
the still image playback operation has not been described, when
printing on a paper medium such as a video printer, for example, it
is acceptable to playback still images as is, with its high pixel
density. Further, when the pixel density is regulated on the video
printer side, means may be provided to convert the still image to
that pixel density.
[0116] On the other hand, when the still image is shown on the
display screen, a still image of a high pixel density may be
converted to a pixel density matching the scan format of the
display screen by appropriating the pixel density conversion means
2 used during recording for use during playback. Due to this
structure, there is no need to exclusively provide pixel density
conversion means for playback only, allowing marked simplification
of the playback display circuit of the electronic camera or the
playback process algorithm.
[0117] As described above, while the imaging means shares a
recording process for still images and moving images, it is
possible to suitably change over the image quality for still images
and the image quality for moving images by the pixel density
conversion means. Further, by changing over the pixel density
conversion means, the moving image is suitably recorded as
appropriate to the scan format of the display screen. Therefore,
the pixel density of the still image is wholly unbound by the scan
format of the display screen, allowing a flexible design suitable
to the intended purpose of the structure.
[0118] While the imaging means shares a recording process for still
images and moving images, it is possible to record still images
with a higher image quality than that of moving images. Due to the
buffer means temporarily storing still images, it is possible to
reliably image still images even during recording of moving
images.
[0119] Accordingly, it has been made possible for the operator to
record, without any concern for whether it is during the recording
of a moving image or a snapshot in which the operator is interested
as a still image having a high image quality. Because the common
component relating to the process within a field or the process
within a frame of a coding conversion component has the dual use of
processing still images and moving images, efficient simplification
is possible of the structure, the calculation process algorithms,
or the like, in an electronic camera. While the imaging means and
the image compression means share the recording process for still
images and moving images, it is possible to record a still image
having a higher image quality than a moving image. Due to the
buffer means temporarily storing still images, it is possible to
reliably image a still image even when recording a moving
image.
[0120] Accordingly, it has been made possible for the operator to
record, without any concern for whether it is during the recording
of a moving image or a snapshot in which the operator is interested
as a still image having a high image quality. By changing over the
changeover switch, the recording switch has a dual use as a switch
activating the still image recording means and the moving image
recording means. Therefore, the operational quality of the image
recording operation has been enhanced.
[0121] The present invention has been described with particularity
in connection with the specific embodiments. It should be
appreciated, however, that changes may be made to the disclosed
embodiments without departing from the invention as defined by the
following claims.
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