JPH0522642A - Digital electronic still camera and its operating method - Google Patents

Abstract

PURPOSE:To monitor a subject image while referring to the screen shown by the image data recorded on a memory card. CONSTITUTION:The screen shown by the image data recorded on a memory card 30 are referred to and at the same time a subject image is monitored. Under such conditions, the image data are read out of the card 30 and stored temporarily in a frame memory 24. Then the image data are transferred to a reproduction part 26 from the memory 24 through a selector 12 while the gate signal GS outputted from a gate signal generating circuit 11 is kept at an L level. When the signal GS is kept at an H level, the image data showing the subject image outputted from an image pickup part 22 are given to the part 26 through the selector 12. Thus the screen shown by the image data recorded on the card 30 is displayed on the screen of the subject image.

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 and its operating method.

[0002]

2. Description of the Related Art A digital electronic still camera can be equipped with a removable memory card, and image data representing a subject image photographed on the memory card is recorded according to a recording mode setting. Some digital electronic still cameras can reproduce the image data recorded on the memory card, and the image data is reproduced according to the setting of the reproduction mode and the reproduction screen is displayed on the display device.

[0003]

When the digital electronic still camera is set to the reproduction mode, it becomes impossible to record the image data on the memory card. Therefore, it is impossible to monitor the subject image to be photographed while referring to the screen represented by the image data recorded on the memory card.

An object of the present invention is to make it possible to monitor a subject image while referring to a screen represented by image data recorded on a memory card.

[0005]

A digital electronic still camera according to the present invention is a storage means for storing image data for one screen, an image pickup means for outputting image data representing a photographed subject image, and an output from the image pickup means. A part of the screen represented by the image data to be displayed is provided with combining means for combining the screen represented by the image data stored in the storage means, and a display device for displaying the combined screen combined by the combining means. It is characterized by

In the operation method of the digital electronic still camera according to the present invention, one screen of image data is stored, the image pickup device is driven to obtain image data representing a subject image, and the obtained image data represents. It is characterized in that the screen represented by the stored image data is combined with a part of the screen, and the combined screen is displayed.

[0007]

According to the present invention, the image data for one screen is temporarily stored in the image memory (frame memory, field memory), and the image data representing the subject image can be obtained from the image pickup device. The screen represented by the image data stored in the image memory is combined and displayed on a part of the screen represented by the obtained image data.

[0008]

According to the present invention, the image data for one screen is stored in the image memory, and the image data stored in the image memory represents a part of the screen represented by the image data obtained from the image pickup device. Screens can be combined and displayed. Therefore, by reading out the image data stored in the memory card and storing it in the image memory, the screen represented by the image data stored in the memory card is combined and displayed on a part of the screen represented by the image data of the subject image. can do.

Therefore, while referring to the screen represented by the image data recorded on the memory card, the subject image can be monitored and, if necessary, the subject image can be taken and recorded.

[0010]

1 is a block diagram showing the electrical construction of a digital electronic still camera according to an embodiment of the present invention.

The overall operation of the digital electronic still camera 20 is controlled by the overall control unit 23.

An image forming lens 21 is included in the digital electronic still camera 20, and a subject image is formed in an image pickup section 22. The image pickup unit 22 includes a CCD, a signal processing circuit, and a digital / analog conversion circuit.
The subject image formed by 21 is taken out as an analog video signal, subjected to necessary signal processing such as amplification, exposure adjustment, and color adjustment, and then converted into digital image data and output. Further, the image pickup unit 22 outputs a horizontal synchronizing signal HD and a vertical synchronizing signal VD.

The memory control unit 10 controls the transfer of image data. The digital electronic still camera 20 has a frame memory that stores image data.
24 is included, and the image data is stored under the control of the memory control unit 10. The digital electronic still camera 20 also includes a data compression / decompression unit 25. In the data compression / expansion unit 25, the image data is subjected to discrete cosine transform and Huffman coding to perform data compression.
In addition, the data compression / decompression unit 25 performs inverse discrete cosine transform and Huffman decoding on the image data subjected to the data compression to decompress the data.

In the digital electronic still camera 20, the image data recorded in the memory card 30 can be reproduced and the subject image to be photographed can be monitored. For this purpose, the reproducing section 26 and the viewfinder 27 are included. There is. The reproducing unit 26 includes a digital / analog conversion circuit, and the input digital image data is converted into an analog video signal and output. The analog video signal output from the reproducing unit 26 is applied to the viewfinder 27 so that it is visually displayed on the viewfinder 27.

FIG. 2 shows an example of the structure of the memory control unit 10. FIG. 3 shows the screen of the viewfinder 27. Digital electronic still camera 20 shown in FIG.
In the above, the screen represented by the image data stored in the frame memory 24 can be displayed in the screen represented by the image data of the subject image obtained from the imaging unit 22. In this case, the screen area of the viewfinder 27 is divided into a display screen area 27A and a small screen area 27B in the display screen area 27A as shown in FIG. A screen represented by the image data of the subject image obtained from the imaging unit 22 is displayed in the display screen area 27A, and a screen represented by the image data stored in the frame memory 24 is displayed in the small screen area 27B.

Referring to FIG. 2, memory control section
The bus control circuit 16 is included in the bus control circuit 16.
Controls the connection of the bus in the memory control unit 10.

The memory control unit 10 has a selector for selecting one of the image data output from the image pickup unit 22 and the image data output from the frame memory 24 and giving it to the reproduction unit 26. 12 included. The selector 12 is switch-controlled by a switch control signal output from the bus control circuit 16. The memory control unit 10 includes a gate signal generation circuit 11. A horizontal synchronizing signal and a vertical synchronizing signal output from the image pickup unit 22 are given to the gate signal generating circuit 11, and the frame memory 24 is displayed in the screen represented by the image data output from the image pickup unit 22 from these synchronizing signals. A gate signal GS for displaying the screen represented by the image data output from is generated. The selector 12 is also switched and controlled by the gate signal GS output from the gate signal generation circuit 11, and is controlled by the bus control circuit 16 so that the image data output from the imaging unit 22 is given to the reproduction unit 26. Even if the gate signal GS output from the gate signal generation circuit 11 is L
When the level is set, the B terminal side is made conductive so that the image data output from the frame memory 24 is given to the reproducing section 26.

The memory control unit 10 also includes a selector 13 and three-state buffers 14 and 15. Either the image data output from the image pickup unit 22 by the selector 13 or the image data obtained from the memory card 30 is reproduced in the frame memory 24 according to the state of the three-state buffers 14 and 15. It is provided either on the part 26 or on the memory card 30.

Further, the memory control unit 10 includes an address generation circuit 17. The address generation circuit 17 is a circuit for generating and outputting address data for reading the image data stored in the frame memory 24. When the gate signal GS output from the gate signal generating circuit 11 is at the H level, the address generating circuit 17 outputs the address data so as to read all the image data for one screen stored in the frame memory 24. However, when the gate signal GS is at L level, address data is generated and output such that predetermined pixels are thinned out so that the screen is displayed in the small screen area 27B of the viewfinder 27.

The digital electronic still camera shown in FIG.
The 20 has a monitor function, a recording function, a playback function, and a reference function.

First, the operation of the monitor function will be described.
The monitor function is a function of displaying the subject image to be photographed on the viewfinder 27 before recording it as image data on the memory card 30.

When the monitor function is set by the setting switch (not shown), the selector 12 is controlled by the bus control circuit 16 so that the A terminal side becomes conductive.

Digital image data representing a subject image is output from the image pickup section 22 and given to the memory control section 10. This digital image data is given to the A terminal side of the selector 12 and given to the reproducing section 26 through the selector 12. It is converted into an analog video signal in the reproducing section 26 and given to the viewfinder 27. As a result, the subject image is displayed on the screen of the viewfinder 27.

Next, the recording function will be described.

When the recording function is set by the setting switch, the A terminal side of the selector 13 becomes conductive. Also, the three-state buffer 14 is enabled and the three-state buffer 15 is disabled.

Digital image data representing a subject image is output from the image pickup section 22 and given to the memory control section 10. This digital image data is given to the A terminal side of the selector 13. Selector 13 for digital image data
Further, it is temporarily stored in a predetermined address based on the address data given to the frame memory 24 through the three-state buffer 14 and output from the address generating circuit 17.

Digital image data is a frame memory
Once stored in 24, the three-state buffer 15 is enabled.

All the digital image data stored in the frame memory 24 is read out for each block of 8 × 8 pixels, and is supplied to the data compression / expansion unit 25 through the three-state buffer 15. The data compression / decompression unit 25 performs data compression by performing discrete cosine transform and Huffman coding. Recording is performed by applying the data-compressed image data to the memory card 30.

Next, the reproducing function will be described.

When the reproduction function is set by the setting switch, the B terminal side of the selector 13 is made conductive, and the three-state buffer 14 is enabled.

The digital image data recorded on the memory card 30 is read out and given to the data compression / decompression unit 25. In the data compression / expansion unit 25, the digital image data is subjected to Huffman decoding and inverse discrete cosine transform processing for each block of 8 × 8 pixels to perform data expansion. The decompressed digital image data is temporarily stored in the frame memory 24 through the selector 13 and the three-state buffer 14.

The B terminal side of the selector 12 is made conductive,
All the image data once stored in the frame memory 24 is read out and given to the reproducing unit 26 through the selector 12.
In the reproducing section 26, it is converted into an analog video signal and given to the viewfinder 27 for visual display. If necessary, an analog video signal may be externally output and displayed on an external display device.

Next, the operation of the reference function will be described. The reference function is to display the subject image on the display screen area 27A of the viewfinder 27 as shown in FIG.
This is a function of displaying a screen represented by the image data recorded in the memory card 30 in the small screen area 27B of the viewfinder 27 for reference of photographing a subject image.

When the reference function is set by the setting switch, the selector 13 of the memory control unit 10 is set to B
The terminal side is made conductive and the three-state buffer
14 is enabled. The image data recorded on the memory card 30 is read out, the data is decompressed in the data compression / decompression unit 25, and the data is given to the memory control unit 10. Digital image data is sent to the frame memory through selector 13 and three-state buffer 14.
Once stored in 24.

Image data representing a subject image is output from the image pickup section 22 and given to the A terminal side of the selector 12.

While the gate signal GS output from the gate signal generation circuit 11 is at H level, the A terminal side of the selector 12 is conductive. Therefore, the image data output from the image pickup unit 22 is given to the reproduction unit 26 through the selector 12 and is visually displayed on the viewfinder 27.

When the gate signal GS output from the gate signal generation circuit 11 becomes L level, the B terminal side of the selector 12 becomes conductive. The view represented by the image data for one screen stored in the frame memory 24 is the viewfinder.
The address generation circuit 17 outputs address data for thinning out and reading out pixels so that the data fits in the small screen area 27B of 27. The image data read from the frame memory 24 is supplied to the reproducing section 26 through the selector 12 while the gate signal GS is being supplied to the selector 12.

Therefore, in the small screen area 27B defined during the period when the gate signal GS is at the L level, the frame
A screen representing the image data stored in the memory 24 is displayed, and a screen representing the subject image is displayed in the display screen area 27A defined during the period when the gate signal GS output from the gate signal generating circuit 11 is at the H level. Will be done. Therefore, the photographer can monitor the subject image to be photographed while referring to the screen represented by the image data already recorded on the memory card 30, and record it on the memory card if necessary. become.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of a digital electronic still camera according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a memory control unit included in a digital electronic still camera.

FIG. 3 shows a relationship between a display screen area and a small screen area of a viewfinder.

[Explanation of symbols]

10 Memory control section 20 Digital electronic still camera 22 Imaging unit 24-frame memory 26 Playback section 27 viewfinder

Claims (2)

[Claims] 1. A storage means for storing one screen of image data, an imaging means for outputting image data representing a photographed subject image, and a storage means for storing a part of a screen represented by the image data output from the imaging means. A digital electronic still camera comprising: a synthesizing means for synthesizing a screen represented by image data stored in the means, and a display device for displaying the synthesized screen synthesized by the synthesizing means. 2. Image data for one screen is stored, an image pickup device is driven to obtain image data representing a subject image, and the image stored in a part of the screen represented by the obtained image data. A method of operating a digital electronic still camera that synthesizes the screens represented by data and displays the synthesized screens.