JP2002199340A - Electronic camera and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera capable of recording an animation file of a necessary and sufficient quality without causing cost up. SOLUTION: The electronic camera 10 is provided with an image pickup device (32) for picking up the image of a subject to generate animation data by using a periodical image signal, and a control part 36. The part 36 functions as an animation generating means for generating animation data by using the periodical image signal and an animation compressing means for performing animation compressing processing of animation data to store it in a storage device. During a time for photographing animation, the animation generating means successively stores the periodical image signal generated by the image pickup device in a work memory to generate the animation data on the work memory, and the animation compressing means carries out animation compressing processing to the animation data on the work memory asynchronously with the animation photographic period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera, and more particularly, to an electronic camera having an image pickup device for generating an image signal of a subject and periodically outputting the signal, and not only a still image of the subject but also a moving image. The present invention also relates to an electronic camera capable of recording an image.

[0002]

2. Description of the Related Art A so-called electronic camera represented by a digital camera is known as a CCD (Charge Coupled Device) or a CCD.
MOS (Complementary Mental Oxide Semiconductor)
It generates an image signal of a subject using a two-dimensional image sensor composed of an imaging device such as a camera, writes the image file to a storage device, and electronically records the image file. It has exceptional convenience in terms of reproduction, erasure of unnecessary images, and ease of transferring image data.

An image recorded by an electronic camera is a still image, but most image sensors focus on the point that a still image signal can be generated at a period of several tens of frames per second. Electronic cameras that enable moving image recording by repeating a recording operation for several seconds have been widely used.

[0004]

However, when a moving image file is simply composed of a plurality of still images as described above, a storage capacity as large as a multiple of one still image is required. In addition to the limitation of the recording time of the moving image, there is a disadvantage that even when the free space of the storage device is reduced, the shooting of the still image is hindered.

[0005] The reproduction quality of a moving image, particularly the smoothness of motion, is determined by the number of frames per second. For example, in order to obtain television broadcast level quality, an image of about 60 frames per second must be stored. To record a moving image for 10 seconds, a large-capacity storage device capable of storing as many as 60 × 10 = 600 frame images (still images) is required. To illustrate this with specific numerical values, a still image having a 640 × 480 pixel configuration is generally 200 KB.
(Kilobytes), the size of a moving image file composed of 600 still images is 600 × 200.
= 120,000 KB, that is, 120 MB (megabytes), and cannot be realized unless a large-capacity storage device such as a hard disk is used. This is a major barrier that cannot be exceeded for an electronic camera having a storage capacity of only several tens of megabytes.

Therefore, in order to effectively use the storage capacity,
It is conceivable to compress the moving image file and write it to the storage device. For example, since the typical technology of moving image compression today is MPEG (Moving Picture Experts Group), if a moving image file is formed using MPEG, the file size of the moving image is reduced at least by an amount corresponding to the compression ratio. And the above-mentioned disadvantages can be solved.

[0007] However, MPEG is a compression technology for storage media. Since it lacks real-time performance in principle, a dedicated compression method is required to simultaneously perform compression processing while capturing frame images output from an imaging device. Since a processing system (a so-called MPEG codec device) is required, or a high-performance microprocessor is required to perform compression by software, there is a problem that any countermeasure leads to an increase in the cost of the electronic camera.

Therefore, an object of the present invention is to provide an electronic camera capable of recording a moving image file of necessary and sufficient quality without increasing the cost.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an imaging device for imaging a subject and generating a periodic image signal, and a moving image data using the periodic image signal. An electronic camera comprising: a moving image generating unit that generates a moving image; and a moving image compressing unit that performs moving image compression processing on the moving image data and stores the moving image data in a storage device.
During the moving image shooting time, the moving image data is generated on the work memory by sequentially storing the periodic image signals generated by the imaging device in the work memory, and the moving image compression unit is asynchronous with the moving image shooting period. And performing a moving image compression process on the moving image data on the work memory.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, taking an electronic camera such as a digital camera as an example.

First, the configuration will be described. FIG. 1 is an external view of an electronic camera. In the figure, an electronic camera 10 includes a lens barrel 12, a finder window 13, a flash window 14, and the like on a front surface of a camera body 11, and a shutter key 15, a flash on / off key 16
And a self-timer key 17, and a power switch 18, a zoom button 19, a recording / playback mode switching switch 20, a finder eyepiece window 21,
A liquid crystal display 22 and a plurality of function keys 23 to 25 are provided.

Here, in the present embodiment, first to third
Up to three function keys 23 to 25, and the first function key 23 is assigned to a menu processing activation key (hereinafter, referred to as “menu key 23”), which will be described later. 24 is assigned to a cursor up / down / left / right key (hereinafter, referred to as “cursor key 24”), and the third function key 25 is assigned to a selection execution key (hereinafter, referred to as “enter key 25”).

The lens barrel 12 contains a photographing lens group having an optical zoom function and a mechanical shutter mechanism. The light receiving surface of an image sensor (not shown) arranged at the rear end of the lens barrel 12 is provided. To form an image of the subject. The finder window 13 is integrated with the finder eyepiece window 21 on the rear side of the camera body 11 and is used when visually confirming the composition. The strobe window 14 is a transmission window through which strobe light is emitted, which will be described later. In many cases, a small lens for adjusting the spread of the luminous flux of the strobe light according to the angle of view of the photographing lens group is arranged on the entire surface. I have.

The shutter key 15 is depressed two steps at the time of photographing. Exposure and the like are set in the first step, and an image is captured (recorded) in the second step. This shutter key 1
Reference numeral 5 is also used as a moving image shooting start key. When the key is pressed down to the second stage in the moving image mode, a still image is periodically captured during a predetermined recording time thereafter, A moving image file including a plurality of captured images is generated and recorded.

A strobe on / off key 16 is used to set whether to permit or prohibit strobe light emission. If the exposure is set to allow, if the underexposure is determined at the time of the first-step-down operation of the shutter key 15, a strobe unit 34 to be described later is driven to emit a strobe light at the time of image capture and set to prohibit. If so, the driving of the flash unit 34 is forcibly prohibited.

A self-timer key 17 is for switching the self-timer on and off, and a power switch 18 is for turning on and off the power of the electronic camera 10. The zoom button 19 changes the angle of view of the optical lens (that is, the zoom ratio). Pressing the "+" side decreases the angle of view, and pressing the "-" side increases the angle. The recording / playback mode switch 20 switches the operation mode of the electronic camera 10 between a recording mode and a playback mode.

The liquid crystal display 22 is a high-resolution color liquid crystal display. Using this liquid crystal display 22, the recorded image can be freely played back and checked at any time, and in the recording mode, a through image can be displayed and used in place of a finder.
If the automatic exposure in backlight shooting or the like is inappropriate, set the appropriate exposure manually while viewing the through image.If the automatic setting of the white balance is inappropriate, view the through image in the same way. However, it is possible to manually select a white balance setting value according to a shooting light source.

FIG. 2 is a conceptual functional block diagram of the electronic camera 10. In this block diagram, for convenience, the imaging unit 32, the image processing unit 33, the strobe unit 34, the operation unit 3
5, each of which is divided into functional blocks such as a control unit 36, a display control unit 37, a display unit 38 (corresponding to the liquid crystal display 22 in FIG. 1), and an image storage unit 39.

The imaging section 32 includes a photographing lens group, a mechanical shutter mechanism, and the like, and captures an image of the subject 31 to generate a color image signal of several tens of frames per second.
Includes a color image sensor such as a CD. The color image sensor includes an auxiliary circuit such as a timing circuit, a sampling hold circuit, and an analog-to-digital conversion circuit. A color image signal having a period of several tens of frames per second (hereinafter simply referred to as an image signal) corresponding to the value is generated, converted into a digital signal by an analog / digital conversion circuit, and output to the image processing unit 33.

The image processing unit 33 separates the input image signal into a luminance component (Y) and color components (Cr, Cb), and performs white balance correction based on a control signal from the control unit 36. YCrCb after white balance correction
The signal is output to the control unit 36. The strobe unit 34 emits auxiliary light (strobe light) 34 a for illuminating the subject 31 in accordance with a drive signal from the control unit 36. Operation unit 3
Reference numeral 5 denotes various operation keys provided on the camera body 11, that is, the above-described shutter key 15, strobe on / off key 16, self-timer key 17, menu key 2,
3. Generate a key signal in response to operations of the cursor key 24 and the enter key 25 and output the key signal to the control unit 36.

The control unit 36 has a CPU (Central Processing Unit) 36a as shown in FIG.
And a program memory 36c and a work memory 36 connected to the CPU 36a via a bus 36b.
d, data memory 36e, input unit 36f, and output unit 36
g etc. are connected. The CPU 36a loads a predetermined control program stored in the program memory 36c into the work memory 36d and executes the same, thereby receiving data from the input unit 36f (image signals from the image processing unit 33, various key signals from the operation unit 35). , The image signal from the image storage unit 39, the data to the output unit 36g (the control signal of the shutter speed and the exposure set value to the imaging unit 32, the white balance correction control signal to the image processing unit 33, the display control) When writing a display signal to the unit 37, a recording image signal to the image storage unit 39, a strobe drive signal to the strobe unit 34), or executing a menu process to be described later, the menu process is executed. The selected various set values are written in the data memory 36e in a nonvolatile manner (the information is not lost even if the power is turned off). And the like, controls the overall operation of the electronic camera 10.

The display controller 37 converts a display signal such as a through image, a preview image, or various setting screens output from the controller 36 into a display format of the display unit 38 and outputs the display signal to the display unit 36. The display control unit 37 and the display unit 38 together constitute a display unit. The image storage unit 39 is configured by a recording medium for recording a captured image (also referred to as a captured image) in a nonvolatile manner. For example, a semiconductor storage device such as a flash memory or a magnetic memory device is used as the recording medium. Can be used. Note that the image storage unit 39 may be detachably mounted on the electronic camera.

Next, the operation will be described. FIG.
6 is a flowchart illustrating an overall outline of a control program executed by a CPU 36a. This program starts to be executed when the power is turned on (when the power switch 18 in FIG. 1 is turned on). First, an initial setting such as an operation check is performed in a step S1, and then a step S2 is performed.
It is determined whether or not the menu key 23 has been pressed, and if it has been pressed, the flow branches to step S3 to execute "menu processing" described later, and then proceeds to the mode determination of step S4. If it is, the process directly proceeds to the mode determination in step S4, and in step S4, it is determined whether the recording / reproduction mode switch 20 is in the recording mode or the reproduction mode based on the current switching state, and the branching process ( The operation of executing “reproduction mode processing” in step S5 and “recording mode processing” in step S6) is repeated.

Hereinafter, the "menu processing" and "recording mode processing (especially, moving picture recording processing)" related to the present invention among the above-described processing will be described in detail.

FIG. 5 is a schematic flow chart of the “menu processing” executed in step S 3 of FIG. 4, and is a diagram showing a transition state of the screen display of the liquid crystal display 22. In this figure, a menu screen 41 corresponds to step S2 in FIG.
Is "YES", that is, FIG.
When the menu key 23 is pressed down by the user during the execution of the loop of FIG.
This is the screen displayed on the screen. On this menu screen 41,
Various menu items including a menu item 41a (hereinafter referred to as “recording mode setting 41a”) for selecting whether to set the recording mode to the still image recording mode or the moving image recording mode are displayed in a list. At the end of the list, the menu screen 41 is closed and FIG.
Menu item 41b (hereinafter referred to as “close 41b”) for returning to the loop of FIG.

When the user operates the cursor key 24 to select the recording mode setting 41 a and presses the enter key 25, the recording mode setting screen 4 is displayed instead of the menu screen 41.
2 is displayed. On the recording mode setting screen 42,
A “still image mode” button 42 a and a “moving image mode” button 42 b are provided.
When a is selected, the recording mode is set to the still image recording mode, the recording mode setting screen 42 is closed, and the menu screen 41 is displayed again. Also, a “movie mode” button 42
When b is selected, the recording mode is set to the moving image mode, the recording mode setting screen 42 is closed, and the menu screen 41 is displayed again.

A menu setting value on the menu screen 41, for example, a setting value such as a recording mode (still image mode / moving image mode) is stored in the data memory 36e of the controller 36.
Is stored in a nonvolatile manner, and the stored value is referred to at the time of executing the next recording mode process.

FIG. 6 is a diagram showing a flowchart of the recording mode processing program executed in step S6 of FIG. When this flowchart is started, first, in step S11, a CCD image, that is, an image signal from the image processing unit 33 is read, and in step S12, the image signal is output to the display control unit 37, and the display unit 38 (the liquid crystal in FIG. The operation of displaying on the display 22) is repeatedly executed until the shutter key 15 is half-pressed. As a result, a through image for composition adjustment is displayed on the liquid crystal display 22 while being updated at a predetermined cycle (the output frame cycle of the imaging unit 32; for example, 60 frames per second).

Thereafter, when half-pressing of the shutter key 15 is detected in step S13, the photographing conditions such as the exposure corresponding to the brightness of the subject and the white balance value corresponding to the type of the light source of the subject are automatically determined in step S14. If the full-press of the shutter key 15 is detected in step S15, it is determined in step S16 whether or not the mode is the moving image mode by referring to the stored value of the data memory 36e. If the mode is the mode, in step S17, the CCD image at that time is used as a still image, for example, a representative technique of still image compression (JPEG:
After compression processing using a Joint Photographic Experts Group or the like, it is recorded in the image storage unit 39.

On the other hand, if it is determined in step S16 that the mode is the moving image mode, a moving image recording process (step S18) is performed instead of the above-described still image recording process (step S17).
Execute

This moving image recording process uses a typical technology of moving image compression (MPEG). Details of the MPEG compression process are as follows. The MPEG standard encoding method (hereinafter simply referred to as “MPEG”) is a CCI for the purpose of applying moving images to storage media systems and communication media systems.
TT H. 261 (encoding for videophone and videoconference)
It is an encoding standard developed from. MPEG is compatible with MC (Mo
Motion Compensation and DCT (Discrete Co
H. sine Transform (Discrete Cosine Transform)). 261, but has a special structure for realizing trick modes such as fast forward, rewind, midway playback, and reverse playback, that is, GOP (Gr.
oup Of Pictures).

FIG. 7 is a schematic diagram showing the syntax (syntax; order and contents to be satisfied by a bit stream) of MPEG. This syntax consists of a sequence layer having several GOPs between a sequence header and a sequence end, and a GOP layer below the sequence layer. The GOP layer includes N picture frames (coded screen data) after the GOP header. It has a structure with. One GOP is one unit of random access, and this unit enables the above trick mode. The types (picture types) of N picture frames are I picture (abbreviation: I), P
This is either a picture (abbreviation: P) or a B picture (abbreviation: B), and the contents of each picture type are as follows.

(1) I picture Abbreviation of Intra-Coded Picture.
This is an image in which all of the screen is intra-coded. It differs from other picture types in that it has independence within the GOP (does not require a reference picture). (2) P picture Predictive-Coded P picture between frames
icture). This is an image predicted in the forward direction from the previous I picture or P picture. (3) B picture Frame-interpolated bidirectional predictive coded image (Bidirectionally coded image)
Predictive-Coded Picture). This is an image that is bidirectionally predicted from preceding and succeeding I or P pictures.

FIG. 8 is a diagram showing an example of the GOP structure. The number of pictures in the GOP (so-called N parameter) is set to "15", and the cycle of the I picture and P picture (so-called M parameter) is set to "3". This is an example of the case where That is, an example is shown in which one GOP is composed of 15 frames, and the number of frames from an I picture (or P picture) to the next P picture is three. In the figure, an I picture is an intra-coded image (a non-predicted coded image) that does not require a reference image.
Further, the P picture and the B picture are forward and bidirectional predictive coded images, respectively. As shown in the figure, the P picture is an already coded I picture or P picture as a reference image, and the B picture is This is a predicted coded image that has been forward-predicted and bidirectionally predicted using the preceding and succeeding I pictures or P pictures as reference images.

FIG. 9 shows the screen order of the original images (B0, B1, I
2, B3, B4, P5,...) Are partially replaced at the stage of the encoding process, and are returned to the original arrangement order at the stage of the reproduced image. Insertion of a B picture in the encoding process is performed by inserting an I picture (or a P picture) before and after the B picture.
And after the encoding of the P picture. For example, focusing on B3 and B4 of the original image, after encoding I2 and P5, B3 and B4 are encoded using these I2 and P5 as reference images, and inserted after I2 and P5. In the order of “I2, B3, B4, P5” at the stage of
2,..., P5, B3, B4 ".

The important parameters of the GOP structure are the above-mentioned “N parameter” and “M parameter”, that is, GO
The number (N) of pictures in P and the period (M) in which I or P pictures appear. There are no restrictions on the use of these parameters. As long as the first GOP on the bit stream satisfies the condition that the first picture is an I-picture and the order of the original pictures is that the last GOP is an I-picture or a P-picture, the value can be freely selected. Is set to a value that is considered to be optimal in terms of image quality, motion of a moving image, and the like. For example, M is often selected to be a value of about 2-3,
N is often selected to be a value such that the random access unit is about 0.4 to 1 second. Incidentally, the optimal value of M is determined by the motion of the moving image (small motion is small M and gentle motion is large M), but the optimal value of N is determined by compromise between image quality and random access unit. This is because, when N is reduced, random access units become finer and the convenience of the trick mode can be improved, but on the other hand, coding efficiency decreases and image quality deteriorates.

FIG. 10 shows the MPEG compression processing (especially GOP
6 is a principle operation flowchart of a layer generation process). In this flowchart, “CN”, “CM”,
“I” and “iΣ” are variables, and their uses are as follows.

CN: Variable for storing N parameters (the number of pictures in a GOP) CM: M parameter (period in which I or P picture appears)
I: a counter variable for counting the period in which an I or P picture appears iΣ: a counter variable for counting the number of pictures in a GOP

In this flowchart, first, the variable CN
, CM and N parameters and M parameters are set (step S41), initial values (0) are set to variables i and iΣ (steps S42 and S43), and initialization processing is executed. Steps S44 to S53) are executed.

In this picture generation processing, first, the screen Gi # of the original image is read (step S44),
It is determined whether or not iΣ = 0 (step S45). If the determination result is YES, an intra-frame coded image (I picture) of the screen GiＧ is generated (step S46).
If NO, it is determined whether or not i <CM (step S48), and if the determination result is YES, the screen Gi 画面
(Step S49), and if NO, an inter-frame forward predictive coded image (P picture) of the screen Gi # is generated (step S50).

When the I picture and the B picture are generated, both the variables i and iΣ are counted up (steps S47 and S52), and when the P picture is generated, the variable i is initialized (step S51). The variable iΣ is counted up (step S52), and in any case, it is determined whether or not iΣ = CN (step S5).
3) If the determination result is NO, a process of repeating the process of reading Gi # (step S44) and thereafter is executed.

FIG. 11 is a GOP structure diagram when the N parameter is "21" and the M parameter is "3". In this GOP structure, the appearance interval of the I picture is every 21 screens set by the N parameter. That is, i
The screen GiΣ (= G0) when Σ = 0 is the first screen of the GOP on the bit stream and satisfies the above-described conditions. Therefore, the screen GiΣ must be an I-picture, but the step S44. , Step S
Such a condition can be satisfied by the generation processing of the I picture up to step 45 and step S46, and the screen G0 that is the first of the GOP on the bit stream can be an I picture. Furthermore, GO on the bit stream
For the screens G1, G2,... After the beginning of P, when the variable i is less than the M parameter (the period in which the I or P picture appears), the screen Gi # at that time can be set to a B picture, and When the variable i satisfies the M parameter, the screen Gi # at that time can be set to a P picture. Therefore, when N is "21" and M is "3", the first screen G0 of the original image G0, G2, G3, G4,... Can be an I picture, and i <CM That is, the screen GiΣ when i <3 (for example, G1 and G2, G4 and G5, G7 and G
,...) Can be B-pictures, and a screen GiΣ when i = 3 (eg, G3, G6, G9,...).
..) Can be P pictures, so that an MPEG image having a picture arrangement corresponding to the N and M parameters set to the optimum values in advance can be formed on the medium.

The point of this embodiment is that the execution timing of the MPEG compression processing (FIG. 10) is after the end of the moving image shooting period, and a dedicated compression processing system (a so-called MPEG codec device) is required. Software compression can be performed without the need for a high-performance microprocessor, and the recording of moving image files of necessary and sufficient quality while avoiding an increase in the cost of the electronic camera 10 can be achieved. .

FIG. 12 is a diagram showing a flowchart of the moving image recording process including the above points, and this flowchart corresponds to step S18 in FIG. That is, when step S18 in FIG. 6 is executed, first, the loop variable i # is set to 0 and initialized (step S6).
1) Then, the image signal from the image processing unit 33 is read (step S62), and the full state of the work memory 36d is determined (step S63). Here, “full state”
This means a state in which the free space of the work memory 36d is less than one still image, and a full state in which a still image can no longer be stored. Step S
When the full state is determined at 63, the MP of FIG.
The EG compression process is executed (step S67). If the work memory 36d is not full, a screen Gi # of the original image is generated in the work memory 36d (step S6).
4) After that, it is determined whether or not the moving image shooting time has elapsed (step S65). If it has elapsed, the MPEG compression processing of FIG. 10 is executed as in the above-described full state determination (step S67), On the other hand, if the movie shooting time has not elapsed,
The loop variable (i 変 数) is incremented by 1 (step S66), and the steps from step S62 are repeated.

According to the moving image recording process, unless the work memory 36d becomes full, a plurality of CCD images (image signals output from the image processing unit 33) captured until the moving image shooting time elapses. ) To the original image screens (G0, G1, G2, G2) as shown in FIG.
4, ‥‥) can be stored in the work memory 36d, and the original image screens (G0, G1,... G2, G4, ‥‥)
Can be used to start the MPEG compression process (see FIG. 10).

Therefore, after the start of the MPEG compression process, the moving image shooting period has already ended, and the control unit 36 can concentrate on only the compression process. As a result, a dedicated compression processing system (MPEG codec device)
, An electronic camera 10 that performs MPEG compression by software, does not require an exceptionally high-performance CPU 36a, and does not cause an increase in the cost of the electronic camera 10. Movie files can be recorded.

As described above, when a moving image is photographed using the electronic camera 10 according to the present embodiment, as shown in FIG. 14, the moving image is captured in the work memory 36d as shown in step A of FIG. Original image screen (G
0, G1, G2, G4,...), And the recording step C of the MPEG file in the image storage unit 39 of the MPEG file can be clearly distinguished.
The capability of the control unit 36 can be occupied by the photographing stage A and the generation stage B, respectively.
a).

In the above embodiment, the moving image stage A
And the generation step B are clearly distinguished, and the step B is executed after the completion of the step A, but is not limited thereto.
When the capability of the control unit 36 is excessive for the stage A (when there is a surplus capability), the surplus capability may be allocated to the stage B. In this case, while performing the stage A, a part of the stage B The processing (the processing covered by the surplus capacity) may be executed in parallel. For example, in the above embodiment, in the moving image stage A, the image signal itself is temporarily stored in the work memory 36d, but an MPEG I picture (intra-frame coded image) is generated from the image signal, and this generated The I picture may be temporarily stored in the work memory 36d. This is preferable because at least the step S46 (I-picture generation) of the MPEG compression processing in FIG. 10 can be omitted in the generation stage B.

[0049]

According to the present invention, when recording a moving image, first,
During the video shooting time, video data is generated on the work memory by sequentially storing the periodic image signals generated by the imaging device in the work memory, and then the video data on the work memory is asynchronous with the video shooting cycle. Since compression processing is performed on video data, even if MPEG, which is a video compression technology for storage media, is used,
Since the compression processing is performed after the completion of moving image shooting, a dedicated function for the compression processing (such as an MPEG codec device) is not required, and a microprocessor is also required to have only a corresponding capability, thereby increasing the cost of an electronic camera. , And a moving image file of necessary and sufficient quality can be recorded.

[Brief description of the drawings]

FIG. 1 is an external view of an electronic camera.

FIG. 2 is a conceptual functional block diagram of the electronic camera 10.

FIG. 3 is a block diagram of a control unit 36.

FIG. 4 is a flowchart showing an overall outline of a control program.

FIG. 5 is a schematic flowchart of menu processing.

FIG. 6 is a diagram showing a flowchart of a recording mode processing program.

FIG. 7 is a schematic diagram showing the syntax of MPEG.

FIG. 8 is a diagram illustrating an example of a GOP structure.

FIG. 9 is a schematic diagram of replacement of pictures.

FIG. 10 is a principle operation flowchart of MPEG compression processing.

FIG. 11 is a GOP structure diagram when the N parameter is “21” and the M parameter is “3”.

FIG. 12 is a diagram showing a flowchart of a moving image recording process.

FIG. 13 is a schematic diagram of a screen (G0, G1, G2, G4,...) Of an original image held in a work memory 36d.

FIG. 14 shows a moving image photographing stage A, an MPEG file generation stage B, and its M in the electronic camera 10 of the present embodiment.
FIG. 7 is a conceptual diagram showing a recording step C of a PEG file in an image storage unit 39.

[Explanation of symbols]

 Reference Signs List 10 electronic camera 31 subject 32 imaging unit (imaging device) 36 control unit (moving image generation unit, moving image compression unit) 36d work memory 39 image storage unit (storage device)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 19/02 H04N 5/225 F H04N 5/225 5/907 B 5/907 101: 00 // H04N 101 : 00 5/92 HF term (reference) 2H054 AA01 BB11 2H104 AA12 AA16 5C022 AA13 AC03 AC12 AC31 AC42 AC69 5C052 GA01 GB06 GC05 GE04 GE06 GE08 5C053 FA08 GB37 HA33

Claims (6)

[Claims] 1. An imaging device that images a subject to generate a periodic image signal, a moving image generation unit that generates moving image data using the periodic image signal, and performs a moving image compression process on the moving image data. An electronic camera comprising: a moving image compression unit that stores a moving image in a storage device, wherein the moving image generation unit sequentially stores a periodic image signal generated by the imaging device in a work memory during a moving image shooting time. An electronic camera, wherein the moving image data is generated on the work memory by the moving image compression unit, and the moving image compression unit executes a moving image compression process on the moving image data on the work memory asynchronously with a moving image photographing cycle. 2. The moving image data stored on the work memory by the moving image generating means is an intra-frame coded image, and the moving image compressing means includes an inter-frame forward prediction coded image from the intra-frame coded image. 2. The electronic camera according to claim 1, wherein the compression processing is performed on the moving image data by predicting a frame interpolation bidirectionally predicted coded image or both. 3. The moving image compression unit starts moving image compression processing on moving image data in the work memory after the lapse of the moving image shooting time or when the full state of the work memory is detected. 2. The electronic camera according to 2. 4. The electronic camera according to claim 1, wherein the moving image compression unit executes an MPEG compression process. 5. A moving image generating process for generating moving image data by using a periodic image signal while generating a periodic image signal by capturing an image of a subject by an imaging device, and a moving image compression process of the moving image data. And a moving image compression processing step of storing the moving image in a storage device, wherein the moving image generation processing step includes, during a moving image shooting time, a periodic image signal generated by the imaging device. The moving image data is generated on the work memory by sequentially storing the moving image data in the work memory, and the image compression processing step performs the moving image compression processing on the moving image data on the work memory asynchronously with a moving image shooting cycle. Electronic camera control method. 6. The moving image data stored in the work memory by the moving image generation processing step is an intra-frame coded image, and the moving image compression processing step includes: 6. The control method for an electronic camera according to claim 5, wherein the compression processing is performed on the moving image data by predicting a coded image or a frame interpolation bidirectionally coded image or both.