JP3169397B2 - Digital electronic still camera and operation method thereof - Google Patents

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 a method of operating the same.

[0002]

2. Description of the Related Art A detachable memory card can be inserted into a digital electronic still camera, and image data representing a photographed subject image is recorded on the memory card in accordance with the setting of a recording mode. In some digital electronic still cameras, image data recorded on a memory card can be reproduced. Image data is reproduced according to the setting of a reproduction mode, and a reproduction screen is displayed on a display device.

[0003]

When a digital electronic still camera is set to a reproduction mode, it becomes impossible to record image data on a 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.

It is an object of the present invention to monitor a subject image while referring to a screen represented by image data recorded on a memory card.

[0005]

SUMMARY OF THE INVENTION A digital electronic still camera according to the present invention captures an object and outputs image data representing the image of the object, reads out image data recorded on a recording medium, and reads out the image data. Reproducing means for reproducing the reproduced image data, a display device for displaying the image, and an image represented by the image data output from the image capturing means, and displaying the reproduced image on a small screen area in the image by the reproducing means. Display control means for controlling the display device so as to display a reduced image of one frame represented by the displayed image data.

An operation method of a digital electronic still camera according to the present invention captures a subject, obtains image data representing the subject image, reads image data recorded on a recording medium, and reproduces the read image data. Displaying an image represented by the image data obtained by the imaging;
A reduced image of one image represented by the reproduced image data is displayed on a display device in a small screen area in the image.

[0007]

According to the present invention, image data representing a subject image can be obtained by imaging the subject. Further, the image data recorded on the recording medium is read and reproduced. A subject image represented by image data obtained by imaging is displayed on the display device, and a reduced image of one frame represented by the reproduced image data is displayed in a small screen area in the subject image.

[0008]

According to the present invention, a reduced image of the image represented by the image data recorded on the recording medium is obtained.
Since the image is displayed in the small screen area in the captured image of the subject, it is possible to compare the image represented by the image data already recorded on the recording medium with the captured image of the subject. While observing the image represented by the image data recorded on the memory card, the subject image obtained by imaging can be monitored. By comparing the image represented by the image data already recorded on the memory card with the subject image obtained by imaging, if it is determined that recording of the subject image obtained by imaging is necessary, an image representing the subject image Data can be recorded on a memory card. If it is determined that recording of the subject image is unnecessary,
There is no need to record on the card. Only image data that really needs to be recorded can be recorded on the memory card.

Since the image displayed in the small screen area in the subject image is a single frame image, it is possible to compare the entire subject image being captured with the entire image represented by the image data already recorded. . Image data representing the image with the better angle can be recorded on the memory card.

[0010]

FIG. 1 is a block diagram showing an electrical configuration 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 an overall control unit 23.

The digital electronic still camera 20 includes an imaging lens 21, and a subject image is formed on an imaging unit 22. The imaging 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, color adjustment, etc., then converted into digital image data and output. The imaging unit 22 outputs a horizontal synchronization signal HD and a vertical synchronization signal VD.

The memory control unit 10 controls the transfer of image data. The digital electronic still camera 20 has a frame memory for storing image data.
24, and image data is stored under the control of the memory control unit 10. Further, the digital electronic still camera 20 includes a data compression / decompression unit 25. In the data compression / decompression unit 25, discrete cosine transform and Huffman coding of the image data are performed, and data compression is performed.
Further, the data compression / decompression unit 25 performs inverse discrete cosine transform and Huffman decoding on the image data subjected to the data compression to perform data decompression.

The digital electronic still camera 20 can reproduce the image data recorded on the memory card 30 and monitor the subject image to be photographed. For this purpose, a reproduction section 26 and a viewfinder 27 are included. I have. The reproduction unit 26 includes a digital / analog conversion circuit, and converts the input digital image data into an analog video signal and outputs it. The analog video signal output from the reproduction unit 26 is provided to the viewfinder 27 and is displayed on the viewfinder 27.

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

Referring to FIG. 2, memory control unit
The bus control circuit 16 includes a bus control circuit 16.
Thereby, the connection of the bus in the memory control unit 10 is controlled.

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 providing the selected image data to the reproduction unit 26. 12 are included. Switching of the selector 12 is controlled by a switching control signal output from the bus control circuit 16. The memory control unit 10 includes a gate signal generation circuit 11. The gate signal generating circuit 11 is supplied with a horizontal synchronizing signal and a vertical synchronizing signal output from the imaging unit 22, and the frame memory 24 is displayed on a screen represented by image data output from the imaging unit 22 from these synchronizing signals. A gate signal GS for displaying a 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 supplied to the reproduction unit 26. Even if the gate signal GS output from the gate signal generation circuit 11 is L
When the signal is at the level, the terminal B is turned on so that the image data output from the frame memory 24 is supplied to the reproducing unit 26.

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

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

Digital electronic still camera shown in FIG.
Reference numeral 20 has a monitor function, a recording function, a reproduction function, and a reference function.

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

When the monitor function is set by a 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 imaging unit 22 and supplied to the memory control unit 10. The digital image data is supplied to the A terminal side of the selector 12 and supplied to the reproducing unit 26 through the selector 12. The data is converted into an analog video signal in the reproducing unit 26 and is supplied to the viewfinder 27. Thus, 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 is turned on. 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 imaging unit 22 and supplied to the memory control unit 10. This digital image data is supplied to the A terminal side of the selector 13. Digital image data is selector 13
And is temporarily stored in a predetermined address based on address data supplied to the frame memory 24 through the three-state buffer 14 and output from the address generation circuit 17.

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

The digital image data stored in the frame memory 24 is all read out for each 8 × 8 pixel block, and supplied to the data compression / decompression 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 providing the 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 of the selector 13 is turned on, and the three-state buffer 14 is turned on.

The digital image data recorded on the memory card 30 is read and applied to the data compression / decompression unit 25. In the data compression / expansion unit 25, Huffman decoding and inverse discrete cosine transform processing are performed for each block of 8 × 8 pixels of digital image data, and data expansion is performed. 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 rendered conductive,
All the image data once stored in the frame memory 24 is read out and supplied to the reproducing unit 26 through the selector 12.
The data is converted into an analog video signal in the reproduction unit 26, and is provided 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 in the display screen area 27A of the viewfinder 27 as shown in FIG.
This function is to display a screen represented by image data recorded on 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
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, decompressed in the data compression / decompression unit 25, and supplied to the memory control unit 10. Digital image data is sent to the frame memory through the selector 13 and the three-state buffer 14.
Stored once in 24.

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

While the gate signal GS output from the gate signal generation circuit 11 is at the H level, the selector 12 has the A terminal side conductive. For this reason, the image data output from the imaging 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 selector 12 becomes conductive at the B terminal side. A screen representing one screen of image data stored in the frame memory 24 is a viewfinder.
Address data to be read by thinning out pixels is output from the address generation circuit 17 so as to fit in the 27 small screen area 27B. Image data read from the frame memory 24 is supplied to the reproducing unit 26 through the selector 12 during a period when the gate signal GS is supplied to the selector 12.

Accordingly, the frame area 27B defined during the period in which the gate signal GS is at the L level has a frame area.
A screen representing the image data stored in the memory 24 is displayed, and a screen representing the subject image is displayed in a display screen area 27A defined during a period when the gate signal GS output from the gate signal generation 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 can record the image on the memory card if necessary. become.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a configuration example of a memory control unit included in the 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 unit 20 Digital electronic still camera 22 Imaging unit 24 Frame memory 26 Playback unit 27 Viewfinder

Claims (2)

(57) [Claims] An image pickup means for picking up an image of an object and outputting image data representing the image of the object ; reading image data recorded on a recording medium;
Reproducing means for reproducing the output image data, a display device for displaying the image, and an output from the imaging means
Display the image represented by the image data
In the small screen area in the image,
And a display control means for controlling the display device so as to display a reduced image of one frame represented by the image data . 2. An image of a subject is obtained, image data representing the subject image is obtained, and image data recorded on a recording medium is read out.
The reproduced image data is reproduced, and the image represented by the image data obtained by the imaging is reproduced.
Is displayed, and the reproduced image data is displayed in a small screen area in this image.
An operation method of a digital electronic still camera that displays a reduced image of one frame represented by data on a display device.