U.S. patent application number 09/247525 was filed with the patent office on 2004-03-25 for electronic camera having continuous shooting function.
Invention is credited to HAYASHI, MASAKI.
Application Number | 20040056960 09/247525 |
Document ID | / |
Family ID | 13159032 |
Filed Date | 2004-03-25 |
United States Patent
Application |
20040056960 |
Kind Code |
A1 |
HAYASHI, MASAKI |
March 25, 2004 |
ELECTRONIC CAMERA HAVING CONTINUOUS SHOOTING FUNCTION
Abstract
An electronic camera having a continuous shooting function
includes: an image capturing unit that captures a subject image; a
setting unit that sets operating parameters related to image
processing performed during image capturing; a resolution
conversion unit that performs resolution conversion on image data
of an image captured by the image capturing unit in correspondence
to a resolution set at the setting unit; an image compression unit
that performs image compression on image data converted by the
resolution conversion unit in correspondence to a compression
factor set at the setting unit; and a continuous shooting unit that
performs continuous shooting of a subject image by continuously
driving the image capturing unit, the resolution conversion unit
and the image compression unit. And: the resolution conversion unit
is capable of performing resolution conversion at least at a high
resolution and at a low resolution that is lower than the high
resolution; the image compression unit is capable of performing
image compression at least at a low compression factor and at a
high compression factor that is higher than the low compression
factor; and when the continuous shooting unit executes continuous
shooting, the image compression unit performs image compression at
the high compression factor if the resolution at the resolution
conversion unit is set to the low resolution.
Inventors: |
HAYASHI, MASAKI;
(KAWASAKI-SHI, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Family ID: |
13159032 |
Appl. No.: |
09/247525 |
Filed: |
February 10, 1999 |
Current U.S.
Class: |
348/207.99 ;
348/E5.042 |
Current CPC
Class: |
H04N 1/2112 20130101;
H04N 5/23245 20130101; H04N 2201/212 20130101; H04N 2201/3247
20130101; H04N 5/232 20130101; H04N 1/212 20130101; H04N 1/215
20130101 |
Class at
Publication: |
348/207.99 |
International
Class: |
H04N 005/225 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 1998 |
JP |
10-61013 |
Claims
What is claimed is;
1. An electronic camera having a continuous shooting function,
comprising: an image capturing unit that captures a subject image;
a setting unit that sets operating parameters related to image
processing performed during image capturing; a resolution
conversion unit that performs resolution conversion on image data
of an image captured by said image capturing unit in correspondence
to a resolution set at said setting unit; an image compression unit
that performs image compression on image data converted by said
resolution conversion unit in correspondence to a compression
factor set at said setting unit; and a continuous shooting unit
that performs continuous shooting of a subject image by
continuously driving said image capturing unit, said resolution
conversion unit and said image compression unit, wherein: said
resolution conversion unit is capable of performing resolution
conversion at least at a high resolution and at a low resolution
that is lower than the high resolution; said image compression unit
is capable of performing image compression at least at a low
compression factor and at a high compression factor that is higher
than the low compression factor; and when said continuous shooting
unit executes continuous shooting, said image compression unit
performs image compression at the high compression factor if the
resolution at said resolution conversion unit is set to the low
resolution.
2. An electronic camera having a continuous shooting function
according to claim 1, wherein: an instruction unit that issues
instructions to ensure that said resolution conversion unit
performs resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor, without having to change settings for the resolution and
the compression factor that have been set by said setting unit, is
provided; and when said continuous shooting unit executes
continuous shooting, said resolution conversion unit performs
resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor in conformance to instructions issued at said instruction
unit.
3. An electronic camera having a continuous shooting function,
comprising: an image capturing unit that captures a subject image;
a setting unit that sets operating parameters related to image
processing performed during image capturing; a resolution
conversion unit that performs resolution conversion on image data
of an image captured by said image capturing unit in correspondence
to a resolution set at said setting unit; an image compression unit
that performs image compression on image data converted by said
resolution conversion unit in correspondence to a compression
factor set at said setting unit; and a continuous shooting unit
that performs continuous shooting of a subject image by
continuously driving said image capturing unit, said resolution
conversion unit and said image compression unit, wherein: said
resolution conversion unit is capable of performing resolution
conversion at least at a high resolution and at low resolution that
is lower than the high resolution; said image compression unit is
capable of performing image compression at least at a low
compression factor and at a high compression factor that is higher
than the low compression factor; and when said continuous shooting
unit executes continuous shooting, said resolution conversion unit
performs resolution conversion at the low resolution if the
compression factor at said image compression unit is set to the
high compression factor.
4. An electronic camera having a continuous shooting function
according to claim 3, wherein: an instruction unit that issues
instructions to ensure that said resolution conversion unit
performs resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor, without having to change settings for the resolution and
the compression factor that have been set by said setting unit, is
provided; and when said continuous shooting unit executes
continuous shooting said resolution conversion unit performs
resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor in conformance to instructions issued at said instruction
unit.
5. An electronic camera having a continuous shooting function,
comprising: an image capturing unit that captures a subject image;
a setting unit that sets operating parameters related to image
processing performed during image capturing; a resolution
conversion unit that performs resolution conversion image data of
an image captured by said image capturing unit in correspondence to
a resolution set at said setting unit; an image compression unit
that performs image compression on image data converted by said
resolution conversion unit in correspondence to a compression
factor set at said setting unit; and a continuous shooting unit
that performs continuous shooting of a subject image by
continuously driving said image capturing unit, said resolution
conversion unit and said image compression unit, wherein: said
setting unit is capable of setting a continuous shooting speed at
said continuous shooting unit at least at a normal speed and at a
high speed that is higher than the normal speed; said resolution
conversion unit is capable of performing resolution conversion at
least at a high resolution and at a low resolution that is lower
than the high resolution; said image compression unit is capable of
performing image compression at least at a low compression factor
and a high compression factor that is higher than the low
compression factor; and when said continuous shooting unit executes
continuous shooting, said resolution conversion unit performs
resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor if the continuous shooting speed is set to the high
speed.
6. An electronic camera having a continuous shooting function
according to claim 3, wherein: an instruction unit that issues
instructions to ensure that said resolution conversion unit
performs resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor, without having to change settings for the resolution and
the compression factor that have been set by said setting unit, is
provided; and when said continuous shooting unit executes
continuous shooting and the continuous shooting speed is set to the
high speed, said resolution conversion unit performs resolution
conversion at the low resolution and said image compression unit
performs image compression at the high compression factor in
conformance to instructions issued at said instruction unit.
7. An electronic camera having a continuous shooting function,
comprising: an image capturing unit that captures a subject image;
a setting unit that sets operating parameters related to image
processing performed during image capturing; a resolution
conversion unit that performs resolution conversion on image data
of an image captured by said image capturing unit in correspondence
to a resolution set at said setting unit; an image compression unit
that performs image compression on image data converted by said
resolution conversion unit in correspondence to a compression
factor set at said setting unit; ad a continuous shooting unit that
performs continuous shooting of a subject image continuously
driving said image capturing unit, said resolution conversion unit
and said image compression unit, wherein: said resolution
conversion unit is capable of performing resolution conversion a
least at a high resolution and at a low resolution that is lower
than the high resolution; image compression at least at a low
compression factor and at a high compression factor that is higher
than the low compression factor; and when said continuous shooting
unit executes continuous shooting, said resolution conversion unit
performs solution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor.
8. An electronic camera having a continuous shooting function
according to claim 7, wherein: an instruction unit that issues
instructions to ensure that said resolution conversion unit
performs resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor, without having to change settings for the resolution and
the compression factor that have been set by said setting unit, is
provided; and when said continuous shooting unit executes
continuous shooting, said resolution conversion unit performs
resolution conversion at the low resolution and said image
compression unit performs image compression at the high compression
factor in conformance to instructions issued at said instruction
unit.
Description
INCORPORATION BY REFERENCE
[0001] The disclosure of the following priority application is
herein incorporated by reference: Japanese Patent Application No.
10-61013, filed Mar. 12, 1998
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electronic camera having
a continuous shooting function. More specifically, the present
invention relates to an electronic camera capable of achieving
higher speed in continuous shooting.
[0004] 2. Description of the Related Art
[0005] The technologies for achieving a higher speed in continuous
shooting in electronic cameras in the known art include the
following. Japanese Laid-Open Patent Publication No. H6-54252
discloses a technology whereby the continuous shooting speed is
increased by simultaneously performing exposure of the subsequent
frame on the image capturing element side while compressing the
image in the preceding frame.
[0006] Japanese Laid-Open Patent Publication No. H5-191700
discloses a technology whereby the length of the image read time is
reduced by reading out an image signal every few lines from the
image capturing element to achieve higher speed in continuous
shooting. Japanese Laid-Open Patent Publication No. H7-135589
discloses a technology whereby the length of the image recording
time is reduced by dividing the data of an image that has been
captured to be recorded onto a plurality of recording media to
achieve a higher speed in continuous shooting.
[0007] The following problems arise with the prior art technologies
described above.
[0008] In regard to the technology disclosed in Japanese Laid-Open
Patent Publication No. H6-54252, if the exposure time is longer
than the length of time required for compression processing, the
exposure operation and the compression processing operation are
executed continuously with a high degree of efficiency. As a
result, the full advantage can be achieved. However, if the
exposure time is shorter than the compression processing time, the
image capturing element side must remain in a standby state for the
read of the image in the succeeding frame until the compression
processing of the preceding frame is completed. Thus, the
continuous shooting speed is reduced by the length of time
corresponding to the wait time.
[0009] The technology disclosed in Japanese Laid-Open Patent
Publication No. H5-191700 requires the use of a special image
capturing element that is capable of reading out the horizontal
lines by specifying individual lines and thus presents a problem in
that a general-purpose image capturing element cannot be
utilized.
[0010] The technology disclosed in Japanese Laid-Open Patent
Publication No. H7-135589, which requires a mechanism for mounting
a plurality of recording media and recording circuits, makes it
difficult to achieve miniaturization of the electronic camera and a
reduction in the cost.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide an
electronic camera capable of achieving higher speed in continuous
shooting, which is achieved through a different approach from those
taken in the prior art technologies described above.
[0012] In order to attain the above object, an electronic camera
having a continuous shooting function according to the present
invention, comprises: an image capturing unit that captures a
subject image; a setting unit that sets operating parameters
related to image processing performed during image capturing; a
resolution conversion unit that performs resolution conversion on
image data of an image captured by the image capturing unit in
correspondence to a resolution set at the setting unit; an image
compression unit that performs image compression on image data
converted by the resolution conversion unit in correspondence to a
compression factor set at the setting unit; and a continuous
shooting unit that performs continuous shooting of a subject image
by continuously driving the image capturing unit, the resolution
conversion unit and the image compression unit. And: the resolution
conversion unit is capable of performing resolution conversion at
least at a high resolution and at a low resolution that is lower
than the high resolution; the image compression unit is capable of
performing image compression at least at a low compression factor
and at a high compression factor that is higher than the low
compression factor; and when the continuous shooting unit executes
continuous shooting, the image compression unit performs image
compression at the high compression factor if the resolution at the
resolution conversion unit is set to the low resolution.
[0013] Another electronic camera having a continuous shooting
function, comprises: an image capturing unit that captures a
subject image; a setting unit that sets operating parameters
related to image processing performed during image capturing; a
resolution conversion unit that performs resolution conversion on
image data of an image captured by the image capturing unit in
correspondence to a resolution set at the setting unit; an image
compression unit that performs image compression on image data
converted by the resolution conversion unit in correspondence to a
compression factor set at the setting unit; and a continuous
shooting unit that performs continuous shooting of a subject image
by continuously driving the image capturing unit, the resolution
conversion unit and the image compression unit. And: the resolution
conversion unit is capable of performing resolution conversion at
least at a high resolution and at a low resolution that is lower
than the high resolution; the image compression unit is capable of
performing image compression at least at a low compression factor
and at a high compression factor that is higher than the low
compression factor; and when the continuous shooting unit executes
continuous shooting, the resolution conversion unit performs
resolution conversion at the low resolution if the compression
factor at the image compression unit is set to the high compression
factor.
[0014] Another electronic camera having a continuous shooting
function, comprises: an image capturing unit that captures a
subject image; a setting unit that sets operating parameters
related to image processing performed during image capturing; a
resolution conversion unit that performs resolution conversion on
image data of an image captured by the image capturing unit in
correspondence to a resolution set at the setting unit; an image
compression unit that performs image compression on image data
converted by the resolution conversion unit in correspondence to a
compression factor set at the setting unit; and a continuous
shooting unit that performs continuous shooting of a subject image
by continuously driving the image capturing unit, the resolution
conversion unit and the image compression unit. And: the setting
unit is capable of setting a continuous shooting speed at the
continuous shooting unit at least at a normal speed and at a high
speed that is higher than the normal speed; the resolution
conversion unit is capable of performing resolution conversion at
least at a high resolution and at a low resolution that is lower
than the high resolution; the image compression unit is capable of
performing image compression at least at a low compression factor
and a high compression factor that is higher than the low
compression factor; and when the continuous shooting unit executes
continuous shooting, the resolution conversion unit performs
resolution conversion at the low resolution and the image
compression unit performs image compression at the high compression
factor if the continuous shooting speed is set to the high
speed.
[0015] Another electronic camera having a continuous shooting
function, comprises: an image capturing unit that captures a
subject image; a setting unit that sets operating parameters
related to image processing performed during image capturing; a
resolution conversion unit that performs resolution conversion on
image data of an image captured by the image capturing unit in
correspondence to a resolution set at the setting unit; an image
compression unit that performs image compression on image data
converted by the resolution conversion unit in correspondence to a
compression factor set at the setting unit; and a continuous
shooting unit that performs continuous shooting of a subject image
by continuously driving the image capturing unit, the resolution
conversion unit and the image compression unit. And: the resolution
conversion unit is capable of performing resolution conversion at
least at a high resolution and at a low resolution that is lower
than the high resolution; the image compression unit is capable of
performing image compression at least at a low compression factor
and at a high compression factor that is higher than the low
compression factor; and when the continuous shooting unit executes
continuous shooting, the resolution conversion unit performs
resolution conversion at the low resolution and the image
compression unit performs image compression at the high compression
factor.
[0016] In each of the above electronic cameras having a continuous
shooting function, preferably, an instruction unit that issues
instructions to ensure that the resolution conversion unit performs
resolution conversion at the low resolution and the image
compression unit performs image compression at the high compression
factor, without having to change settings for the resolution and
the compression factor that have been set by the setting unit, is
provided; and when the continuous shooting unit executes continuous
shooting, the resolution conversion unit performs resolution
conversion at the low resolution and the image compression unit
performs image compression at the high compression factor in
conformance to instructions issued at the instruction unit.
[0017] It is to be noted in each of the above electric cameras that
descriptions of "high compression factor", "low resolution" and
"high speed" do not always mean "the highest compression factor",
"the lowest resolution" and "the highest speed", respectively.
Among these options, they mean "compression factor at a high
compression factor side", "resolution at a low resolution side" and
"speed at a high speed side", respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a block diagram illustrating the structure of an
embodiment;
[0019] FIG. 2 is a flowchart illustrating the main routine executed
during photographing;
[0020] FIG. 3 is a flowchart illustrating the mode setting
operation;
[0021] FIG. 4 is a flowchart illustrating the single-shot
operation;
[0022] FIG. 5 is a flowchart illustrating the continuous shooting
operation; and
[0023] FIG. 6 is a flowchart illustrating the high-speed continuous
shooting operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] The following is an explanation of an embodiment of the
present invention given in reference to the drawings.
[0025] FIG. 1 is a block diagram illustrating the structure of the
electronic camera in this embodiment. In FIG. 1, a photographic
optical system 11 is provided inside the main body of the
electronic camera. On the side of the photographic optical system
11 where the image space is present, the image capturing surface of
a CCD image capturing element 13 is provided. The CCD image
capturing element 13 is driven by a control pulse supplied by a CCD
drive circuit 13a. An analog image signal from the CCD image
capturing element 13 is provided to an image processing circuit 15
as digital image data after going through an A/D conversion circuit
14. The image processing circuit 15 manages the overall image
processing achieved by the hardware, including the image
compression processing and the image synthesis processing for
monitor display.
[0026] The image data for monitor display output from the image
processing circuit 15 are displayed on a liquid crystal monitor 15a
via a liquid crystal drive circuit (not shown). A timing signal for
indicating the drive timing of the CCD image capturing element 13
is transmitted from the image processing circuit 15 to the CCD
drive circuit 13a. A control signal is provided to the image
processing circuit 15 by a CPU 16.
[0027] The CPU 16 performs exchange of image data with an image
data bus of the image processing circuit 15, a memory 18 and a
flash memory card 19, via a system bus 17. An operating button
group 21 that includes a shutter release button 22, a menu button
23 and a zoom button 24 is connected to the CPU 16.
[0028] In the actual circuit, the CPU 16 described above is
constituted as a multi-processor comprising a processor for image
processing that manages the overall image processing by software
and a processor for system control that monitors the operating
buttons and the like at the electronic camera.
[0029] In this embodiment, the CCD image capturing element 13 and
the CCD drive circuit 13a constitute an image capturing unit, the
operating button group 21 and the "function of setting various
operating parameters" achieved by the CPU 16 constitute a setting
unit, the "function of achieving resolution conversion (or
changing) for image data" achieved by the image processing circuit
15 constitutes a resolution conversion unit, the "function of
performing image compression of image data" achieved by the image
processing circuit 15 constitutes an image compression unit and the
"function of executing continuous shooting by controlling the image
processing circuit 15 and the CCD drive circuit 13a" achieved by
the CPU 16 constitutes a continuous shooting unit.
[0030] It is to be noted that the function of changing the settings
related to image compression or resolution conversion is achieved
through the "function of automatically setting the high-speed
continuous shooting mode as part of the mode setting operation" of
the CPU 16.
Main Routine in the Embodiment
[0031] The following is an explanation of the operation performed
in the embodiment.
[0032] FIG. 2 is a flowchart illustrating the main routine executed
during photographing in the embodiment. First, the CPU 16 makes a
decision as to whether or not an input operation for mode setting
has been performed through the operating button group 21 (FIG. 2
S1).
[0033] An input operation for mode setting in this context may be,
for instance, an operation during which the menu button 23 in the
operating button group 21 is pressed down for 0.2 seconds or
longer. When such an input operation is performed, the CPU 16
proceeds to execute the mode setting operation shown in FIG. 3
(FIG. 2 S2). If no input operation has been performed, the CPU 16
makes a decision as to whether or not the shutter release button 22
has been pressed (FIG. 2 S3). Until the shutter release button 22
is pressed, the CPU 16 returns to the operation in step S1 to
standby for the mode setting operation.
[0034] Once the shutter release button 22 is pressed, (FIG. 2 S3
YES), the CPU 16 makes a decision in regard to the setting status
for the photographing mode (FIG. 2 S4). If the single-shot mode is
set for the photographing mode, the CPU 16 proceeds to execute the
single shot operation shown in FIG. 4 (FIG. 2 S5). If the
continuous shooting mode has been set, the CPU 16 proceeds to
execute the continuous shooting operation in FIG. 5 (FIG. 2
S6).
[0035] If high-speed continuous shooting mode has been set, the CPU
16 proceeds to execute the high-speed continuous shooting operation
in FIG. 6 (FIG. 2 S7). When this sequence of operations is
completed, the CPU 16 returns to step S1 in preparation for the
next mode setting operation and the next operation in which the
shutter release button 22 is pressed.
[0036] It is to be noted that the "single-shot mode" in this
context refers to a normal mode in which one photographic frame is
photographed in response to an operation in which the shutter
release button 22 is pressed once and that the "continuous shooting
mode" refers to a mode in which a plurality of photographic frames
are continuously photographed at a constant rate while the shutter
release button 22 is held down. The "high-speed continuous shooting
mode" is a mode in which continuous shooting is performed at a
higher speed compared to that in the "continuous shooting
mode."
[0037] Next, the operating routines described above are
individually explained.
Mode Setting Operation
[0038] FIG. 3 is a flowchart illustrating the mode setting
operation. After the mode setting operation starts, the CPU 16
displays a menu list screen on the liquid crystal monitor 15a via
the image processing circuit 15. The operator operates the zoom
button 24 to move the cursor position in the screen and operates
the shutter release button 22 to select an appropriate menu item,
having positioned the cursor. By repeating this type of interactive
operation, a mode setting operation for setting various modes is
executed. During the execution of the mode setting operation, the
zoom button 24 is used as a cursor positioning button and the
shutter release button 22 is used as a selection deciding button,
with their original zoom and shutter release functions
prohibited.
[0039] The following is an explanation of three types of mode
setting operations, i.e., "resolution setting", "compression factor
setting" and "continuous shooting setting".
(1) Resolution Setting Operation
[0040] When the menu item "resolution setting" is selected (FIG. 3
S11 YES), the CPU 16 displays the options, "high resolution mode"
and "low resolution mode" in the menu (FIG. 3 S12). At this point,
if the "high resolution mode" is selected in the menu, the CPU 16
first sets an internal flag at the image processing circuit 15 to
the high resolution mode (FIG. 3 S13) and then returns to the main
routine in FIG. 2.
[0041] If the "low resolution mode" is selected in the menu, the
CPU 16 first sets the internal flag at the image processing circuit
15 to the low resolution mode (FIG. 3 S14). With the low resolution
mode set in this manner, the CPU 16 makes a decision as to whether
or not the single-shot mode has been set (FIG. 3 S15). If the
single-shot mode has been set (FIG. 3 S15 YES), the CPU 16 directly
returns to the main routine in FIG. 2. If a mode other than the
single-shot mode (the continuous shooting mode or the high-speed
continuous shooting mode) has been set (FIG. 3 S15 NO), the CPU 16
first changes the setting of the internal flag at the image
processing circuit 15 to high-speed continuous shooting mode (FIG.
3 S16) and then returns to the main routine in FIG. 2. Through the
operation described above, the setting for the resolution mode is
completed.
[0042] It is to be noted that the "high resolution mode" in this
context refers to a mode in which the data of an image that has
been captured by the CCD image capturing element 13 are used with
the number of pixels unchanged without thinning the pixels. The
"low resolution mode" refers to a mode in which the pixels in the
data of an image captured by the CCD image capturing element 13 are
thinned at a specific rate to use image data having a reduced
number of pixels.
(2) Compression Factor Setting Operation
[0043] When the menu item "compression factor setting" is selected
(FIG. 3 S17 YES), the CPU 16 displays the options, "low compression
mode" and "high compression mode" in the menu (FIG. 3 S18). If the
"low compression mode" is selected in the menu, the CPU 16 first
sets the internal flag at the image processing circuit 15 to the
low compression mode (FIG. 3 S19), and then returns to the main
routine in FIG. 2. It is to be noted that the low compression mode
in this context refers to a mode in which an appropriate low
compression factor is set to assure the quality of the image.
[0044] If the "high compression mode" is selected in the menu, the
CPU 16 sets the internal flag at the image processing circuit 15 to
the high compression mode (FIG. 3 S20). It is to be noted that the
high compression mode in this context refers to a mode in which an
appropriate high compression factor is set, mainly for the purpose
of reducing the length of the image transfer time.
[0045] As the high compression mode is set in this manner, the CPU
16 makes a decision as to whether or not the single-shot mode has
been set (FIG. 3 S21). If the single-shot mode has been set (FIG. 3
S21 YES) the CPU 16 directly returns to the main routine in FIG. 2.
If, on the other hand, a mode other than the single-shot mode (the
continuous shooting mode or the high speed continuous shooting
mode) has been set (FIG. 3 S21 NO), the CPU 16 first changes the
setting of the internal flag at the image processing circuit 15 to
the high-speed continuous shooting mode (FIG. 3 S22) and then
returns to the main routine in FIG. 2. Through the operation
described above, the setting of the compression mode is
completed.
(3) Continuous Shooting Setting Operation
[0046] When the menu item "continuous shooting setting" is selected
(FIG. 3 S23 YES), the CPU 16 displays options, the "high-speed
continuous shooting mode" and the "continuous shooting mode" in the
menu (FIG. 3 S24). If the "high-speed continuous shooting mode" is
selected in the menu, the CPU 16 first sets the internal flag at
the image processing circuit 15 to the high-speed continuous
shooting mode (FIG. 3 S25) and returns to the main routine in FIG.
2.
[0047] If the "continuous shooting mode" is selected in the menu,
the CPU 16 sets the internal flag at the image processing circuit
15 to the continuous shooting mode (FIG. 3 S26). As the continuous
shooting mode is set in this manner, the CPU 16 first changes the
setting of the internal flag at the image processing circuit 15 to
the high resolution mode (FIG. 3 S27, S28) and then returns to the
main routine in FIG. 2. Through the operation described above, the
setting of the continuous shooting mode is completed.
Single Shot Operation
[0048] FIG. 4 is a flowchart illustrating the single shot
operation.
[0049] After the single shot operation starts, the CPU 16 makes a
decision as to whether or not photographing is enabled by verifying
the battery state, the quantity of electrical charge at the strobe,
the remaining capacity in the flash memory card 19 and the like
(FIG. 4 S31).
[0050] If a decision is made that photographing is disabled (FIG. 4
S31 NO), the CPU 16 displays a warning to that effect on the liquid
crystal monitor 15a and then returns to the main routine in FIG. 2.
If it is decided that photographing is enabled (FIG. 4 S31 YES),
the CPU 16 takes in image data from the CCD image capturing element
13 and calculates the correct aperture value, the correct exposure
time and the quantity of contrast (FIG. 4 S32).
[0051] Based upon the contrast quantity thus calculated, the CPU 16
moves the photographic optical system 11 backward and forward to
execute the scanning and contrast detecting type AF control (FIG. 4
S33). When the AF control is completed, the CPU 16 adjusts the
aperture diameter of the photographic optical system 11 (also used
as the lens shutter) in correspondence to the correct aperture
value (FIG. 4 S34). Following these preparations, the CPU 16 wipes
or discharges all unnecessary electrical charge at the CCD image
capturing element 13 via the CCD drive circuit 13a, to start
photoelectric storage of a new image of the subject (FIG. 4
S35).
[0052] When the correct exposure time has elapsed in this state,
the CPU 16 closes the lens shutter of the photographic optical
system 11 to end the photoelectric storage of the subject image
(FIG. 4 S36).
[0053] In the following step, the CPU 16 reads out the image data
from the CCD image capturing element 13 via the CCD drive circuit
13a (FIG. 4 S37). The image data thus read out are first digitized
via the A/D conversion circuit 14 and are then taken into the image
processing circuit 15. The image processing circuit 15 temporarily
stores the image data in the memory 18.
[0054] If the high resolution mode has been set in advance (FIG. 4
S38 NO), the image processing circuit 15 does not execute
resolution conversion (or changing) since the data of the captured
image are used with the number of the pixels unchanged, without
thinning any pixels. If, on the other hand, the low resolution mode
has been set in advance (FIG. 4 S38 YES), the image processing
circuit 15 thins out some pixels from the image data in the memory
18 to reduce the resolution (FIG. 4 S39).
[0055] Next, the image processing circuit 15 undertakes processing
such as DCT (discrete cosine transfer), quantization and variable
length encoding before it executes image compression for the image
data. If the low compression mode has been set in advance (FIG. 4
S40 NO), the image processing circuit 15 performs image compression
for the image data by using a quantizing table for a low
compression factor (FIG. 4 S41). If, on the other hand, the high
compression mode has been set in advance (FIG. 4 S40 YES), the
image processing circuit 15 performs image compression for the
image data by using a quantizing table for a high compression
factor (FIG. 4 S42).
[0056] After filing the image data that have been compressed in
this manner, the CPU 16 stores the filed image data in the flash
memory card 19 (FIG. 4 S43). Through the sequence of operations
described above, the single shot operation is completed.
Continuous Shooting Operation
[0057] FIG. 5 is a flowchart illustrating the continuous shooting
operation. It is to be noted that the operation performed at
S51.about.S63 in FIG. 5 are identical to that in the single shot
operation explained earlier (FIG. 4 S31.about.S43). In this
embodiment, the continuous shooting operation is executed by
repeating an operation (FIG. 5 S52.about.S63) identical to that in
the single shot operation. The CPU 16 ends the continuous shooting
operation as soon as the pressure on the shutter release button 22
is released (FIG. 5 S65) to return to the main routine in FIG.
2.
[0058] If the remaining capacity at the flash memory card 19
becomes insufficient during such a continuous shooting operation
(FIG. 5 S64), the CPU 16 immediately interrupts the continuous
shooting operation to return to the main routine in FIG. 2.
High-Speed Continuous Shooting Operation
[0059] FIG. 6 is a flowchart illustrating the high-speed continuous
shooting operation. When the high-speed continuous shooting
operation starts, the CPU 16 makes a decision as to whether or not
photographing is enabled by checking the battery state, the
quantity of the electrical charge at the strobe, the remaining
capacity at the flash memory card 19 and the like (FIG. 6 S71).
[0060] If a decision is made that photographing is disabled (FIG. 6
S71 NO), the CPU 16 displays a warning to that effect on the liquid
crystal monitor 15a and then returns to the main routine in FIG. 2.
If it is decided that photographing is enabled (FIG. 6 S71 YES),
the CPU 16 calculates the correct aperture value, the correct
exposure time and the quantity of contrast based upon image data
obtained from the CCD image capturing element 13 (FIG. 6 S72).
[0061] Based upon the contrast quantity thus calculated, the CPU 16
moves the photographic optical system 11 backward and forward to
execute the scanning and contrast detecting type AF control (FIG. 6
S73). When the AF control is completed, the CPU 16 adjusts the
aperture diameter of the photographic optical system 11 (also used
as the lens shutter) in correspondence to the correct aperture
value (FIG. 6 S74). Following these preparations, the CPU 16 wipes
or discharges all the unnecessary electrical charge at the CCD
image capturing element 13 via the CCD drive circuit 13a, to start
a new photoelectric storage of the image of the subject (FIG. 6
S75).
[0062] When the correct length of exposure time has elapsed in this
state, the CPU 16 closes the lens shutter at the photographic
optical system 11 and ends the photoelectric storage of the subject
image (FIG. 6 S76). The CPU 16 reads out the image data from the
CCD image capturing element 13 via the CCD drive circuit 13a (FIG.
6 S77). The image data thus read out are first digitized via the
A/D conversion circuit 14 and are then taken into the image
processing circuit 15. The image processing circuit 15 temporarily
stores the image data in the memory 18.
[0063] The image processing circuit 15 reduces the resolution of
the image data in the memory 18 regardless of the resolution mode
that has been set in advance (FIG. 6 S78). Next, the image
processing circuit 15 performs image compression for the image data
in the memory 18 at the high compression factor regardless of the
compression mode that has been set in advance (FIG. 6 S79).
[0064] After filing the image data that have been compressed in
this manner, the CPU 16 temporarily stores the filed image data in
a buffer area provided in the memory 18.
[0065] By repeating this sequence of operations (FIG. 6
S72.about.S80), the high-speed continuous shooting operation is
executed. If the pressure on the shutter release button 22 is
released during such a high-speed continuous shooting operation
(FIG. 6 S83), the CPU 16 first transfers the image files in the
buffer area to the flash memory card 19 in a batch for recording
(FIG. 6 S84) and then returns to the main routine in FIG. 2.
[0066] In addition, if the remaining capacity at the flash memory
card 19 is anticipated to become insufficient (FIG. 6 S81) or if
the buffer capacity of the memory 18 becomes insufficient (FIG. 6
S82) during the high-speed continuous shooting operation, the CPU
16 immediately transfers the image files in the buffer area to the
flash memory card 19 in a batch for recording (FIG. 6 S84) and then
returns to the main routine in FIG. 2. Through the sequence of
operations described above, the high-speed continuous shooting
operation is completed.
[0067] With the operation in the embodiment achieved as described
above, if the operator performs a setting operation to set the low
resolution mode while the continuous shooting mode is set, the mode
is reset to the high-speed continuous shooting mode automatically
(see FIG. 3 S15, S16). In the high-speed continuous shooting mode,
image compression is performed at the high compression factor
regardless of the compression mode setting (see FIG. 6 S79). Thus,
the quantity of data after DCT quantization during the image
compression processing is reduced so that the length of time
required for variable length encoding and the like can be reduced.
In addition, since the image data quantity after the compression is
bound to be small, the length of time required for image recording
in the memory 18 can be reduced. For these reasons, the length of
time required for photographing one frame is reduced, thereby
making it possible to achieve a higher speed in continuous shooting
with an even higher degree of reliability.
[0068] If, on the other hand, the operator performs an operation to
set the high resolution mode while the continuous shooting mode is
set, the mode is not necessarily reset to the high-speed continuous
shooting mode (see FIG. 3 S13). In this case, since the resolution
conversion and the image compression are executed in conformance to
the mode setting, it is also possible to execute continuous
shooting of high quality images at high resolution with a low
compression factor.
[0069] In this embodiment, if the operator performs an operation to
set the high compression mode while the continuous shooting mode is
set, the mode is automatically reset to the high-speed continuous
shooting mode (see FIG. 3 S21, S22). In the high-speed continuous
shooting mode, the image data are converted with low resolution
regardless of the setting for the resolution mode (see FIG. 6 S78).
Thus, the amount of arithmetic processing to be performed for the
image compression is reduced to achieve a reduction in the length
of compression processing time. Furthermore, with the quantity of
image data reduced after the compression, the length of time
required for image recording, too, is reduced. For these reasons,
the length of time required for photographing a given frame is
reduced so that a higher speed in continuous shooting is achieved
with an even higher degree of reliability.
[0070] If the operator performs an operation for setting the low
compression mode while the continuous shooting mode is set, the
mode is not necessarily reset to the high-speed continuous shooting
mode (see FIG. 3 S19). In this case, since the resolution
conversion and the image compression are executed in conformance to
the mode settings, it is also possible to execute continuous
shooting of images of high quality at the high resolution and the
low compression factors.
[0071] In the embodiment, the operator may directly select the
high-speed continuous shooting mode (FIG. 3 S25). In this
high-speed continuous shooting mode, the image data are converted
with a low resolution and a high compression factor regardless of
the settings for the resolution mode and the compression mode (see
FIG. 6 S78, S79). Thus, a higher speed in continuous shooting is
achieved with a higher degree of reliability by reducing the length
of time required for compression processing and the length of time
required for image recording.
[0072] In addition, the operator may directly select the continuous
shooting mode. Since the resolution conversion and the image
compression are executed in conformance to the mode settings in
this case, it is also possible to execute continuous shooting of
high quality images at the high resolution and at the low
compression factors.
[0073] In the embodiments, when setting the high-speed continuous
shooting mode, the settings for the compression mode and the
resolution mode at that point, are maintained unchanged.
Consequently, when the high-speed continuous shooting mode is
cleared, the operation can directly return to the original
compression mode and resolution mode. This operation eliminates the
necessity for resetting the compression mode and the resolution
mode when the high-speed continuous shooting mode is cleared, to
further improve the operability of the electronic camera.
[0074] It is to be noted that while the high-speed continuous
shooting mode is automatically set during a mode setting operation,
the present invention is not limited to this example. For instance,
the image processing circuit 15 may forcibly execute image
processing in the low resolution mode (or the high compression
mode) if the high compression mode (or the low resolution mode) is
set in the continuous shooting processing routine. Through such an
operation, too, a higher speed in continuous shooting can be
realized with a high degree of reliability.
[0075] In addition, in the embodiment described above, continuous
shooting is possible in two different modes, i.e., the continuous
shooting mode and the high-speed continuous shooting mode. The
embodiment assumes a structure in which, if the high compression
mode or the low resolution mode is set while the "continuous
shooting mode" is set, the mode is automatically switched to the
"high-speed continuous shooting mode". However, the present
invention is not limited to this structural example. For instance,
there may be only one mode for continuous shooting to perform
high-speed continuous shooting when the high compression mode or
the low resolution mode is set and to perform low-speed continuous
shooting in other cases. Namely, the photographer may have a choice
only as to whether or not continuous shooting is to be performed,
with high-speed continuous shooting automatically performed if the
high compression mode or the low resolution mode is set and
low-speed continuous shooting performed under other conditions. In
this case, only the processing in which the internal flag is set to
the "continuous shooting mode" in step S26 among steps
S24.about.S28 in FIG. 3 needs to be performed without having to
select a menu item for continuous shooting setting.
[0076] Furthermore, if there is only one mode available for the
continuous shooting, high-speed continuous shooting may be
unconditionally performed if the "continuous shooting mode" is
selected. In this case, only the processing for setting the
internal flag to the "high-speed continuous shooting mode" in step
S25 needs to be performed among steps S24.about.S28 in FIG. 3.
[0077] Moreover, while continuous shooting is started up by
pressing down the shutter release button 22 while the "continuous
shooting mode" or the "high-speed continuous shooting mode" is set
in the embodiment described above, the startup operation for
continuous shooting in the present invention is not limited to this
example. For instance, continuous shooting may be started up and
continued in response to a sustained pressure on the shutter
release button 22.
* * * * *