JPH06261280A - Digital electronic still camera with consecutive photographing function - Google Patents

Abstract

PURPOSE:To store only a picture needed especially from among the photographed pictures limited by the storage capacity of a storage medium at the time of consecutive photographing. CONSTITUTION:The digital electronic still camera is provided with a free area management section managing the idle capacity of a storage medium 9 and a consecutive recording management section 11 managing the picture storage area where the photographing order of each frame photographed in consecutive photographing and each frame. Further, it is provided with a control section 13 reading out the information of the consecutive photographing recording management section 11 when the free area of the storage medium 9 is running short of in the consecutive photographing and circulately re-writing the frame needed for a storage medium 12 while eliminating the indesired frame by opening the storage area where the frame photographed in the specific order is recorded as a free area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital electronic still camera for converting a photographed image into a digital signal and recording it.
Specifically, it relates to a recording method of image data of continuous shooting.

[0002]

2. Description of the Related Art In recent years, a digital electronic still camera has been put into practical use which photoelectrically converts a subject image optically formed by a solid-state image pickup device and digitizes and records an analog image signal output from the solid-state image pickup device. . A semiconductor memory such as a memory card is used as a storage medium for a digital electronic still camera, and a memory card that can be obtained at a reasonable price by a user has a storage capacity of 1 to 4 at most.
It's about a megabyte.

On the other hand, the storage capacity required for recording one frame of an image having a resolution similar to that of an NTSC color television is about 1 megabyte. Can only record. Therefore, various still image information amount compression methods for compressing the image information amount to 1/10 to 1/20 without deteriorating the image quality have been put to practical use by reducing the redundancy using the correlation of images. There is.

Here, in Japanese Patent Laid-Open No. 2-248186,
A digital electronic still that provides a buffer memory for multiple frames to realize high-speed continuous shooting, temporarily records high-speed continuously recorded image data, and reads the image data from the buffer memory after the end of shooting for encoding. A camera is proposed.

Further, in Japanese Patent Laid-Open No. 63-287180,
A digital electronic camera capable of recording the latest several frames of images by means of cyclically changing the storage area in the image storage means has been proposed. When continuous shooting is performed by this camera, images of several frames before and after a desired moment are proposed. It is possible to shoot.

[0006]

By the way, in order to compress the information amount of a still image, it is necessary to perform various calculations, and even if dedicated hardware is used, it is not possible to perform encoding in real time. Especially, there was a problem that high-speed continuous shooting was not possible.

Further, even if the photographed image is compressed and recorded, the number of photographable images is about 50. Therefore, for example, when high-speed continuous shooting of 5 frames per second is performed, it is at most 10 seconds. There is a problem that only continuous shooting can be performed, and continuous shooting for a long time cannot be performed.

This has also been a problem in conventional silver salt film cameras. Here, JP-A-2-248
The camera proposed by No. 186 is effective for continuous shooting of a small number of images in a short time, but it requires a large amount of buffer memory to increase the number of images taken during continuous shooting.
It is not suitable for continuous shooting over a long period of time because it leads to an increase in size and cost of the camera.

Further, the camera proposed in Japanese Patent Laid-Open No. 63-287180 is effective when it is desired to leave only the images before and after a desired moment, but when photographing a long-term change in a subject, the camera is used. The inconvenience arises that the image at the start is overwritten and erased.

The present invention has been made in view of the above circumstances, and when recording continuously shot images in a storage medium during continuous shooting, when the free space of the storage medium runs out during shooting. , The continuous shooting is thinned out at a predetermined interval, and rewriting is performed cyclically while opening the storage area where the image data is already recorded. It is an object of the present invention to provide a digital electronic still camera capable of recording only the optimum frame among the number of images.

[0011]

In order to achieve the above object, the present invention provides a digital electronic still camera for recording photographed image data as digital image data, and an image storage means for storing image data of a plurality of photographed frames. A continuous area recording section that manages an empty area in the image storage means, a continuous shooting record management section that stores the shooting order of each frame that has been continuously shot and the storage area of the image storage means, If the free area management unit determines that there is no free area in the image storage unit, the information of the continuous shooting recording management unit is read and the storage area in which the frames in a predetermined order are stored is read. A control unit that transfers an address to the free space management unit and controls so that the corresponding storage region can be rewritten as a free space. To provide a digital electronic still camera, which comprises Bei.

[0012]

With the above structure, the free space management unit manages the transferred storage area as a rewritable free space,
By recording the newly captured image data in the released recording area, it is possible to record the image data of the effective frame while remaining the number of captured images due to the limitation of the storage capacity.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the first embodiment of the present invention. The lens 1 and the diaphragm 2 form an optical system to form a subject image. The solid-state image sensor 3 photoelectrically converts the subject image formed by the optical system, and outputs it as an electric signal under the control of the solid-state image sensor drive circuit 4. A /
The D converter 5 converts the analog image signal output from the solid-state image sensor 3 into a digital signal and outputs the digital signal. The video signal processing unit 6 performs video signal processing on the digital image signal, and the D / A converter 7 converts the digital image signal into an analog image signal. The liquid crystal finder 8 reproduces an analog image signal as a visible image. The buffer memory 9 temporarily records a plurality of captured image data.

The free area management unit 10 stores and manages information regarding a recordable free area in the buffer memory 9. The continuous shooting recording management unit 11 stores and manages information regarding the shooting order of continuous images obtained during continuous shooting and the storage area of the buffer memory 9 in which the image data of each frame is recorded.

The memory card 12 is attachable to and detachable from the camera body and records digital image data temporarily recorded in the buffer memory 9. The CPU 13 comprehensively controls the shooting operation, the temporary recording operation in the buffer memory 9, the free area management unit 10 and the continuous shooting recording management unit 11, the operation of transferring image data from the buffer memory 9 to the memory card 12, and the like. .

Next, the operation will be described. The digital electronic still camera shown in FIG. 1 can be switched between the normal shooting mode and the continuous shooting mode by a mode setting means (not shown), and the control flow in the CPU 13 when shooting with this camera is shown in the flowchart of FIG. Will be described with reference to.

The photographer decides a desired photographing angle while checking the image displayed on the liquid crystal finder 8 and presses a release button (not shown) to start the photographing operation (step S1), and the image signal processing section 6 outputs it. The buffer memory 9 in which the digital image data to be designated is specified based on the free area information managed by the free area management unit 10.
Is temporarily recorded in the empty area of
2) The information of the storage area of the captured image data in the buffer memory and the shooting order is recorded in the continuous shooting recording management unit 11 (step S3).

At this time, if the continuous shooting mode is set, the shooting operation is continued while the photographer continues to press the release button (step S4).

When an image of one frame is recorded in the buffer memory 9, the CPU 13 refers to the information in the free area management unit 10 and has a free area in the buffer memory 9 in which the photographed image data can be recorded. It is determined whether or not (step S5), and if there is a free area, the process returns to step S2 to temporarily record the frame of the image to be captured next.

On the other hand, in step S5, the free space management unit 10
If it is determined that there is no free area in the buffer memory 9 from the information of No. 3, the CPU 13 reads the information recorded in the continuous shooting recording management unit 11 and resets the recorded header information of the frames shot in a specific order. Buffer memory 9
A part of the storage area is released (step S6).

When the CPU 13 releases a part of the storage area of the buffer memory 9, it rearranges and changes the shooting order information of the continuous shooting recording management section 11 (step S7), and also releases the free area of the buffer memory 9. Is transferred to the free space management unit 10 (step S8), and the process returns to step S2.

In the continuous shooting mode, the shooting ends when the photographer releases the release button (step S4), and the CPU 1
Under the control of No. 3, the sequential frame image data recorded in the buffer memory 9 is sequentially read and transferred to the memory card 12, and at the same time, the shooting order information managed by the continuous shooting recording management unit 11 is the header information. Is transferred as the shooting frame number (step S9).

In the normal photographing mode, the photographing is finished when the image data of the first photographed frame is recorded in the buffer memory 9 (step S4), and the image data is read from the buffer memory 9 under the control of the CPU 13. It is transferred to the memory card 12 (step S9).

When all the image data recorded in the buffer memory 9 is normally transferred to the memory card 12,
By resetting the contents of the free space management unit 10 and the continuous shooting recording management unit 11, the buffer memory 9 is released and all operations are completed (step S10).

In the present embodiment, the description has been given of the example in which the photographed image data is temporarily recorded in the buffer memory 9. However, this is the writing speed or erasing of the flash memory which does not require the memory holding current. Since the speed is slow, it is configured to temporarily record in a high-speed writable memory, and does not limit the configuration and effects of the present invention. Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing the overall configuration of the second embodiment of the present invention. Here, the same components as those in FIG. 1 are designated by the same reference numerals. The image compression unit 14 is configured to perform information amount compression by removing redundant components by utilizing the correlation of images of digital image data.

Next, FIG. 4 shows the transfer operation of the recorded contents of the buffer memory in FIG. 3 to the memory card (step S
9 is a flowchart showing in detail 9), and its operation will be described. The shooting operation up to temporary recording in the buffer memory 9 in the continuous shooting mode is as described in the first embodiment. When the photographer releases the release button in the continuous shooting mode and the shooting operation ends, the CPU 13
Thus, the continuous shooting record management information of the continuous shooting record management unit 11 is read (step S91).

The CPU 13 first reads the image data of the first frame from the buffer memory 9 based on the read continuous recording management information (steps S92 and S93), and the image compression unit 14 compresses the image information amount. And then transfer to the memory card 12 (step S9
4).

Further, when the image data read from the buffer memory 9 is normally transferred to the memory card 12, C
The PU 13 confirms the presence / absence of untransferred image data of consecutive frames in the buffer memory 9, and if there is untransferred image data (step S95), it reads the next frame (step S96).

When the above operation is repeated and all the image data recorded in the buffer memory 9 is transferred to the memory card 12, the transfer operation ends.

By performing the above transfer operation, the image data recorded on the memory card are arranged in a time series, and continuous frames can be displayed without a special image header for reproduction. It will be played in series.

The present invention and the conventional example will be compared and described with reference to FIG. FIG. 5 is a comparative explanatory diagram of the conventional technology and the present invention in the case of performing continuous shooting of 20 frames in a digital electronic still camera having a buffer memory having a storage capacity capable of temporarily recording taken image data for 8 frames. is there. The relationship between the frames that were shot during continuous shooting and the frames that are actually recorded in the storage medium when recording was performed with each recording control method was shown.

Here, as a conventional example, a recording control system in which image data temporarily recorded in a buffer memory at the time of continuous shooting is transferred to a memory card after completion of photographing is set as a conventional example 1, and is recorded in the buffer memory cyclically. A recording control method for recording several frames of the above is shown as Conventional Example 2.

In the recording method of the first conventional example, after shooting 8 frames, the free space in the buffer memory is exhausted and the shooting operation cannot be continued.

In the recording method of the second conventional example, the latest 8 frames of images are recorded in the buffer memory at the time when the photographing operation is completed.
The image data of the frame is overwritten and lost.

In the recording method according to the present invention, although the time interval between frames that are continuously captured and the interval between frames that are finally recorded are different, it is possible to see how the subject changes from the start to the end of continuous shooting. Can be recorded.

[0036]

As described above, according to the digital electronic still camera of the present invention, the continuous shooting mode is controlled by managing the empty area of the storage medium and the shooting order of each frame continuously shot and the storage area during continuous shooting. If the free space on the storage medium runs out on the way,
Effective for a limited number of shots due to the limited storage capacity of the storage medium by recording control that releases the storage area where the image data of a specific frame is recorded and rewrites so as to thin out the consecutive frames that have been shot. It is possible to perform continuous shooting in which only the appropriate frames are recorded.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of operations in the embodiment of the present invention.

FIG. 4 is a flowchart showing a flow of an operation of transferring the recorded contents of the buffer memory to the memory card in the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a relationship between an image captured during continuous shooting and an image actually recorded in a storage medium between a conventional example and the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens 2 Aperture 3 Solid-state imaging device 4 Solid-state imaging device drive circuit 5 A / D converter 6 Video signal processing unit 7 D / A converter 8 Liquid crystal finder 9 Buffer memory 10 Free area management unit 11 Continuous shooting recording management unit 12 Memory Card 13 CPU 14 Image compression unit

Claims (1)

[Claims] 1. An image storage unit for storing image data of a plurality of captured frames, a free area management unit for managing a free area in the image storage unit, a shooting order of each frame which is continuously shot, and the image storage. A continuous shooting record management unit that stores information about the storage area of the means, and if the empty area management unit determines that there is no free area in the image storage unit during continuous shooting, the continuous shooting record management unit A control unit that reads out information, transfers the address of a storage area in which frames in a predetermined order are stored to the free area management unit, and controls so that the corresponding storage area can be rewritten as a free area. And a digital electronic still camera having a continuous shooting function.