JPH0670315A - Video telephone set - Google Patents

Abstract

PURPOSE:To provide the video telephone set on which picture data are displayed through magnification/reduction without use of a special device. CONSTITUTION:A video telephone set being a sender of picture data fetches picture data of 1/4 region shown in hatched lines in figure (a) from picture data of a full-size pattern picked up by a camera 16 without thinning a picture compression section 342 compresses the picture data and the compressed data are sent to a communication opposite party via a communication control section 33 and an ISDN line. On the other hand, upon the receipt of the compressed picture data as to the 1/4 region, the video telephone set being a receiver applies picture reproduction about the thinned picture data to be compressed and processed. The picture data of a prescribed region fetched by the sender are displayed on the display device fully on its screen as shown in hatched line data shown in figure (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a videophone, and more particularly to a videophone capable of enlarging and reducing a received image.

[0002]

2. Description of the Related Art With the spread of ISDN (Integrated Services Digital Communication Network), videophones using ISDN have been developed. In addition to a conventional telephone that performs only voice communication, this videophone is also capable of communicating a self-portrait of the caller and images of materials and the like. In such a videophone, a voice input from a handset is encoded and a CCD (Charge coupled device) is used.
) Etc., the image of the speaker taken by a camera is compressed and coded, and both are transmitted from the ISDN line via the ISDN communication control section. On the other hand, the voice and image from the other party's speaker are also transmitted in a compressed and encoded state, so they are decoded and played back to output the voice from the handset and display the played image. Outputting to the device.

In some of such videophones, a received image can be enlarged or reduced so that it can be displayed on a display. FIG. 11 shows a circuit configuration of a conventional videophone for performing such enlargement and reduction.
In the videophone of FIG. 11, the image captured by the camera 1 is encoded by the image encoding device 2 and then the data transmission device 3
Is transmitted to the other party's videophone via a telephone line or an ISDN line. On the other hand, the encoded image data transmitted from the other party of the call is received via the data transmission device 3 and stored in the memory 5 under the control of the central control unit 4. Then, the image data stored in the memory 5 is decoded by the image decoding device 6 and then displayed on the display device 7 as an image of the other party. And
When enlarging or reducing an image, the image data decoded by the image decoding device 6 is stored in the image memory 8, and the decoded image data is used to perform processing such as pixel interpolation and thinning. And the display device 7
I am trying to display it.

[0004]

As described above, in the conventional videophone, when the image data is enlarged or reduced and displayed on the screen, a dedicated device and an image memory for performing the enlargement and reduction are required. Met. For this reason, the entire system becomes complicated and causes a cost increase. Therefore, an object of the present invention is to provide a videophone capable of enlarging and reducing image data for display without using a special device.

[0005]

According to a first aspect of the present invention, there is provided a camera for taking an image, and a first taking-in means for taking in image data of a predetermined area from image data of a full size screen taken by the camera. Second capturing means for thinning and capturing image data of a full-size screen captured by the camera, image data captured by the first capturing means and the second capturing means, full size captured by the camera Compression processing means for compressing any of the image data, transmission means for transmitting the compressed image data compressed by the compression processing means together with audio data, and receiving means for receiving the compressed image data and audio data. Playback processing means for playing back the compressed image data received by the receiving means according to the compression state, and a display for displaying the image data played back by the playback processing means. Play is provided in a videophone, and the received image data is expanded by performing a reproduction process in which the compressed image data of a predetermined area is compressed in the reproduction processing unit, with the thinned image data being compressed. The above-mentioned object is achieved by reproducing by reproducing. According to another aspect of the present invention, a camera that captures an image, a first capturing unit that captures image data of a predetermined area from image data of a full size screen captured by the camera, and a full size captured by the camera Second image capturing means for thinning out image data on the screen, image data captured by the first image capturing means, second image capturing means, and full-size image data captured by the camera are compressed. Compression processing means, transmission means for transmitting the compressed image data compressed by this compression processing means together with audio data, receiving means for receiving the compressed image data and audio data, and compressed image data received by this receiving means. The videophone is equipped with a reproduction processing means for reproducing the image data according to the compression state and a display for displaying the image data reproduced by the reproduction processing means. In the reproduction processing means, the received image data is reduced and reproduced by performing the reproduction processing on the compressed image data of the thinned image data as if the compression processing was performed on the predetermined area. To achieve.

[0006]

According to the first aspect of the invention, in a videophone for transmitting image data, image data of a predetermined area, for example, 1/4 area, is fetched from the image data of a full size screen, and this is transmitted after compression processing. . On the other hand, in the videophone that receives the image data, when the compressed image data for the predetermined area is received, the reproduction processing unit performs the reproduction process as if the thinned image data was compressed. By displaying this on the display, the image data of the predetermined area captured by the transmitting side is enlarged and displayed on the entire display on the receiving side. According to the invention described in claim 2, in the videophone for transmitting the image data, the image data of the full-size screen is thinned out and fetched, and the compressed image data is transmitted after being compressed. On the other hand, in the videophone that receives the image data, when the compressed image data of the thinned image data is received, the reproduction processing unit performs the reproduction process as if the predetermined region was compressed. By displaying this on the display, the image data of the full-size image captured on the transmission side is reduced and displayed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a videophone of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows the external structure of a videophone. As shown in FIG. 1, the videophone 10 includes a base 11, a handset 12 is arranged on the left side of the base 11, and a display support 13 is arranged on the right side.

The handset 12 is for carrying out a telephone call and includes a microphone and a speaker (not shown). A speaker 14 and various operation keys 15 are arranged on the upper surface of the base 11. The operation keys 15 include a speaker volume knob 15 for adjusting the volume of the speaker 14.
1, a handset volume knob 152 for adjusting the volume of the handset 12, various function keys 153 associated with the telephone function,
Numeric keypad 154 for dialing, recording key 155 associated with TV function, privacy key 156, menu screen key 157 for displaying menus such as various mode settings
Various operation keys 15 such as are arranged.

A camera 16 composed of, for example, a CCD or a white balance adjusting circuit is arranged on the front side of the upper portion of the display support 13 so as to photograph the speaker. The camera 16 is configured so that the photographing angle can be freely adjusted by an adjusting unit (not shown) arranged at the rear of the display supporting unit 13. Also, on the side surface of the display support 13 on the handset 12 side,
A display 17 for displaying an image is attached. The display 17 displays the image of the other party transmitted from the videophone of the other party, and also displays a menu screen in accordance with various modes designated by the operation of the operation keys 15, and the camera 16 Various images such as displaying the image captured in the image sent to the other party by combining with the image of the other party, and further displaying a predetermined message text or icon (pictogram) alone or by combining with the image. Is displayed.

A VT (not shown) is provided on the rear side surface of the base portion 11.
VTR connection terminals 25a to 25d for connecting R26
Are arranged. VT connected to this connection terminal 25
R26 and camera 16 attached to videophone 10
A camera switch key 18 for switching between and is arranged on the right side surface of the display support 13. Further, on the right side surface of the display support portion 13, a shooting condition switching key 19 for switching shooting conditions such as an aperture according to the brightness of a room shot by the camera 16, a color of an image displayed on the display 17 (RGB ) Color adjustment knob 2 for adjusting
0 and the cap 21 are arranged at predetermined positions. The cap 21 is a screw (not shown) for fixing the display 17 to the display support portion 13.
Is for covering. Display 1
Reference numeral 7 is a display support portion 1 formed by a spring so as to be vertically rotatable about the center of the cap 21.
It is attached by a biasing force in three directions.

FIG. 2 shows a schematic configuration of a circuit of such a videophone. As shown in this FIG.
The videophone includes a central processing unit 31. This central processing unit 31 is a well-known CPU (central
processing unit) 311, a memory 312 including a ROM (read only memory) storing various programs and data for communication and a RAM (random access memory) serving as a working memory storing various data. I have it.

This RAM is provided with an image memory area for storing compressed image data transmitted from the other side, image data for holding or displaying privacy, and the like. In addition, various data areas are secured in this RAM, and for example, an incoming call can be made in an incoming call restriction mode that is set by operating the function keys 153 and the ten-key pad 154, for example, restricting incoming calls other than the designated caller. Various data such as the telephone number of the other party, speed dial, and various flags indicating states such as waiting, making a call, receiving a call, and communicating are stored. In addition, the central processing unit 3
1 is a chipset 31 as a communication interface
3. A key controller 314 for controlling instruction signals input from various keys of the operation keys 15 is provided.

The central processing unit 31 is provided with a communication control unit 3 via a bus line (ISA bus) 32 such as a data bus.
3 and the image processing unit 34 are connected. Also,
Via the ISA bus 32, various information processing devices such as a personal computer, CAD (computer aided design), DTP (desk top publishing) can be connected. The communication control unit 33 uses the I
It has an SDN connection terminal 331 and is connected to an ISDN line. This communication control unit 33 uses a communication control signal,
It controls transmission and reception of data such as audio data and image data. The image processing unit 34 performs communication control of the image reproduction unit 341 that reproduces the compressed image data transmitted from the videophone of the other party via the communication control unit 33, and the image data supplied from the camera 16 or the VTR 26. An image compression unit 342 that performs compression processing for transmission by the unit 33 is provided.

The video telephone 10 further includes an image processing unit 34.
D / A (digital / analog) converter 3 connected to
6. Image combining unit 37 connected to the D / A conversion unit 36
Also, an audio control unit 38 connected to the image composition unit and the communication control unit 33 is provided. The audio control unit 38 includes a voice input / output terminal 25 of the handset 12, the speaker 14, and the VTR connection terminal 25.
a, 25c and the chip set 313 are connected. The audio control unit 38 switches between audio switching, hold tone, and DTMF (dual tone multiplex freq).
uency), and various controls such as volume adjustment of the speaker 14 and the handset 12.

The D / A conversion unit 36 converts the image data reproduced by the image reproduction unit 341 of the image processing unit 34 from a digital signal to an analog video signal (NTSC; national tel).
D / A section 36 to convert to an evision system committee)
1 and A / D for converting an analog video signal supplied from the image synthesizing unit 37 into digital image data
A section 362 is provided. The digital image data converted by the A / D unit 362 is the image compression unit 3 of the image processing unit 34.
42.

The image synthesizing section 37 includes an amplifier (AMP) 37.
1, picture-in-picture section 372, AMP3
73 and a changeover switch unit 374, and VT
It is connected to the video input / output terminals 25b and 25d of the R connection terminal 25 and the display 17. AMP371 is
An analog video signal taken by the camera 16 or V
The analog video signal supplied from the VTR 26 via the TR connection terminal 25b is amplified. Both video signals are selected by the camera switching key 18 in FIG.
It is determined by the connection state of the changeover switch unit 374 by the switching operation of. The analog video signal amplified by the AMP 371 is normally supplied to the A / D unit 362, and when the image synthesizing function is designated by the operation key 15, the A / D unit 362 and the picture-in-picture unit 37 are operated.
It is supplied to both of the two.

Picture-in-picture section 372
AMPs the image data supplied from the D / A unit 361.
Supply to 373. Further, when the image synthesizing function is designated to be operated by the operation keys 15, the video signal supplied from the D / A unit 361 (the image signal transmitted from the videophone on the other end of the call) and the AMP 371 are supplied. Video signal (self-portrait or VTR taken by camera 16
The video signal supplied from 26) is synthesized according to the designated state of the operation keys 15, and the synthesized video signal is AMP.
Supply to 373. AMP373 is supplied NTSC
The signal is amplified and supplied to the display 17. The display 17 displays the supplied video signal in color.

FIG. 3 shows a circuit configuration in the image processing section 34. As shown in FIG. 3, the image processing unit 3
The image reproducing unit 341 of No. 4 stores a first-in first-out FIFO memory 341a in which the image data supplied from the ISA bus 32 is stored, a Huffman decoding unit 341b that performs Huffman decoding of the image data in the FIFO memory 341a, and an image after decoding. Block memory 341 in which data is stored
c, the image data stored in the block memory 341c is read out, motion compensation inter-frame prediction, DCT (discret
A compression / reproduction unit 341d for reproducing image data compressed by cosine transform or the like is provided.

The block memory 341c has an area for two frames, alternately stores the Huffman-decoded image data, and the area not storing the image data (the area of the previous frame). The image data is read out from the area where the image data is stored) and is compressed and reproduced. Then, when the recording key 155 (FIG. 1) is pressed, the compressed image data before reproduction stored in the block memory 341c is supplied to the central processing unit 31 via the ISA bus 32 and stored in the memory 312. RAM
It is designed to be stored in.

On the other hand, the image compression section 342 has a setting parameter storage section 342a in which parameters for setting image quality are stored, a block memory 342b in which digital image data supplied from the D / A conversion section 36 is stored, A compression unit 342c that compresses the image data stored in the block memory 342b by motion compensation inter-frame prediction, DCT, etc., a Huffman coding unit 342d that further Huffman-codes the compressed image data, and a buffer memory 3
42e. Setting parameter storage unit 342a
Is connected to the CPU 311 via the ISA bus 32, and when the caller specifies the image quality, each parameter specified by the caller or the other party's speaker is stored.
Further, it is set and changed automatically by an instruction from the CPU 311.

Next, the operation of the embodiment thus constructed will be described. First, the normal operation of the videophone will be described. In normal operation of videophone, CPU3
11 detects each state FG (flag) of the memory 312 and performs each process, and in the process, changes a predetermined state FG to shift to the next process or the previous process. That is, normally, the outgoing call or incoming call is monitored by repeating the waiting process. When an outgoing or incoming call is detected, a predetermined FG is changed, and then the process proceeds. In the outgoing call and incoming call processing, when normal processing is performed, the processing shifts to in-communication processing. Then, when the in-communication process ends, or when a specific operation or the like is performed in the incoming or outgoing call process, the process returns to the waiting process and the outgoing or incoming call is monitored again. As described above, in the videophone, there are respective processings such as a waiting processing, a calling processing, a receiving processing, and a communication processing. However, in the present embodiment, since the communication processing is the main point, only the communication processing will be described in detail. I will explain to you.

Basic Processing FIG. 4 shows the basic processing operation of processing during communication. In the processing during communication in FIG. 4, first, the CPU 311
Monitors whether or not the calling party has issued a communication disconnection request to the communication control unit 33 via the ISDN line (step 201). If there is no disconnection request (step 2)
01; N), the handset 12 is on-hook (step 202; Y), and the hold key or the speaker key is pressed in advance (step 203; Y), there is a call such as a hold or a transmission pause. However, each effective functional process is performed (step 204).

That is, the following processes are performed as the respective functional processes. Hold process ... When the hold key of the function keys 153 is pressed, the hold screen is displayed on the display 17, and the hold screen data is transmitted from the communication control unit 33 to the ISDN line.
As the hold screen data, the image data captured by the camera 16 in advance or supplied from the VTR 26 is stored in the RAM of the memory 312, and this image data is read and used. When the hold screen setting is the default (the one prepared as standard and not rewritable), only the hold code is transmitted, and the side receiving the code displays the default screen on the display 17.

Transmission pause process ... When the transmission pause key is selected, a screen having no correlation with the previous frame is captured from the image data supplied from the camera 16 or the like and displayed on the display 17, and the image data is communication-controlled. It is transmitted from the unit 33 to the other party. Further, the display 17 displays an icon indicating the paused state.

Privacy processing ... Privacy key 1
When 56 (FIG. 1) is pressed, the corresponding code is transmitted to the other party of the call via the communication control unit 33, and the icon indicating the privacy state is displayed on the display 1
Display on 7. On the other hand, in the videophone that has received the privacy code, the privacy screen is displayed on the display 17.

Recording process: When the recording key 155 is pressed, a request is made to the videophone of the other party to transmit image data having no correlation with the previous frame. Then, when receiving image data that has no correlation,
The received image data is kept in the compressed state, or the image data after being reproduced by decoding is stored in the memory 3
It is stored in the RAM 12 and recording is started. When the VTR 26 is connected, the compressed image data is reproduced, and the D / A unit 361 shown in FIG.
You may make it record on VTR26 via the connection terminal 25d. In this case, since the image displayed on the display 17 is recorded as it is, the correlation of the transmitted image data does not matter.

Menu process ... Menu screen key 157
When is pressed, a recording medium selection icon is displayed on the display 17, and it is possible to perform one-shot recording for recording a screen of only a specific frame or tape selection. In the case of one-shot recording, when a request to send image data with no frame correlation is issued to the other party's videophone and image data with no correlation is received, the image data remains compressed or played back for decoding, etc. The subsequent data is stored in the memory 312.

Image Processing When the self-portrait processing is selected, the self-portrait captured by the camera 16 or the VTR 26 is displayed on the display 17 on the display 17 instead of the image data transmitted from the other party's videophone. The caller sets and changes the screen size and the image quality mode while looking at the self-portrait displayed on the display 17. In this image quality mode, there is a specified image quality mode that sends image data with a specified image quality,
There is an automatic image quality mode in which the movement of image data is monitored and an appropriate image quality of the self-portrait is selected according to the movement. On the other hand, when the partner image processing is selected, the partner image processing screen is displayed on a part of the display 17 on which the partner image is displayed. The caller specifies the screen size of the partner image and the image quality mode of the partner image according to the instruction on the partner image processing screen while looking at the partner image displayed on the display 17. When the image quality mode of the partner image is designated, the CPU 3
11 transmits the corresponding control signal from the communication control unit 33 to the other party's videophone. Upon receiving this control signal, the other party's videophone changes to the designated image quality.

After the respective functional processings described above are completed, the image communication processing is performed (FIG. 4, step 20).
5). That is, when the ISDN board (communication control unit 33) is in the data transmission OK state, the CPU 311 takes in the image data compressed by the image compression unit 342, attaches a communication header to each transmission block, and sends it from the communication control unit 33. Send. On the other hand, if the communication control unit 33 has received data,
This is received and stored in the RAM of the memory 312. Then, the compressed image data is sent to the image processing unit 34, D /
After processing such as reproduction through the A conversion unit 36 and the image composition unit 37, the display 17 is displayed for each frame of image data.
To display. The received voice data is sent to the handset 12 and the speaker 1 via the audio control unit 38.
4 or VTR connection terminal 25a.

In step 202, when the handset 12 is in the off-hook state (step 202;
N), it is determined whether or not a predetermined key input is made from the operation keys 15 (step 206). If a key input has been made (step 206; Y), the process proceeds to each functional process of step 204, and if no key input has been made (step 20).
In 6; N), the process proceeds to the image communication process of step 205.

On the other hand, in step 201, when the other party issues a disconnection request (step 201; Y) and it is normally terminated (step 207; Y), or in step 203, both the hold key and the speaker key are pressed. If it has not been pressed in advance (step 203; N), C
The PU 311 performs communication end processing (step 20).
8). That is, as the communication end processing, the handset 1
The videophone on the side where 2 is on-hook sends a disconnection message to the voice line, and sends a disconnection message to the data line when release is returned. On the other hand, the videophone on the disconnected side sends out the data disconnection message when receiving the audio disconnection message. Here, the display 17 on the calling side displays the charge and the call time, and the display 17 on the receiving side displays only the call time.

After that, the CPU 311 turns the communicating FG in the ON state into the OFF state and changes the waiting FG in the OFF state into the ON state (step 209). Go to (Step 14). At step 207, as in the case where an error occurs in the image data line, if the process is not completed normally (step 207; N), communication error processing is performed (step 210). That is, as the communication error processing, the line of the image data is disconnected and only the voice communication is performed.
In this case, the display 17 displays only a predetermined image stored in the RAM in advance and a message indicating that there is a communication error.

Next, the transmission / reception operation of image data during the communication processing will be described with reference to FIGS. 2 and 3. Self-portrait taken by camera 16 or VTR2
The video signal of the video supplied from 6 is amplified by the AMP 371 and then supplied to the D / A conversion unit 36. Here, the analog video signal is converted into digital image data by the A / D unit 362 and then supplied to the image processing unit 34.

The image data supplied to the image processing section 34 is stored in the block memory 342b as original image data. The compression unit 342c takes in predetermined data from the original image data stored in the block memory 342b according to the parameters stored in the setting parameter storage unit 342a. Then, the motion-compensated inter-frame prediction, image compression by DCT, etc. is performed on the captured image data. The compressed image data is further Huffman encoded and sequentially stored in the buffer memory 342e. The image data stored in this buffer memory 342e is
Taken into the central processing unit 31 via the ISA bus 32,
Further, via the ISA bus 32, the ISD is transmitted from the communication control unit 33.
Sent to N lines. The transmitted image data is reproduced on the videophone of the other party and displayed on the display 17.

On the other hand, the image data from the other party's videophone received by the communication control unit 33 is supplied to the central processing unit 31 via the ISA bus 32. Since this image data has been compressed by the other party's videophone, it is sequentially supplied to the image reproducing unit 341 for reproduction by a method opposite to that compressed by the image compressing unit 342. Image reproduction unit 341
Image data supplied to the FIFO memory 341 sequentially.
After being stored in a, decoded by the Huffman decoding unit 341b, stored in the block memory 341c in frame units. The data stored in the block memory 341c is reproduced by the IDTC or the like in the compression reproduction unit 341d and supplied to the D / A conversion unit 36.

The digital image data supplied to the D / A conversion unit 36 is converted into an analog video signal by the D / A unit 361, and the picture-in-picture unit 372.
Then, if necessary, it is combined with the video signal of the self-portrait supplied from the camera 16 or the like, supplied to the display 17 via the AMP 373, and displayed.

Image Quality Processing Next, the image quality and size changing operations of the self image and the partner image will be described. The quality of the image of yourself or the other party during communication,
When it is desired to change the size, the image quality changing process or the size changing process is performed. If the image quality is reduced and the size is reduced, the amount of data per sheet becomes smaller, the number of frames that can be transmitted per second increases, and the image becomes closer to a moving image. vice versa,
If the image quality is improved and the size is increased, the amount of data per sheet is increased, and the still image is displayed like frame-by-frame.

Therefore, in this embodiment, the image quality and the size can be freely changed according to the purpose of communication with the other party, and the optimum images can be selected from each other. That is, the CPU 311 uses the original image in the block memory 342b to determine the setting parameter storage unit 34.
According to the parameter stored in 2a, one frame of data is fetched and the compressed data size is determined. When the compressed data size is 1 Kbytes or less, it is determined that the image is a motionless image, and each parameter is changed in the direction of improving the image quality (direction of approaching the original image). On the other hand, when the compressed data size becomes larger than 2K [bytes], it can be determined that the image has a lot of motion, and therefore each parameter is changed in the direction of decreasing the image quality. When the compressed data size is 1 to 2 Kbytes, the image compression is performed with the current parameters.

FIG. 5 is for conceptually explaining each state of the image quality processing. Image quality change and size conversion are
This is performed by fetching predetermined data from the original image data stored in the block memory 342b according to the parameters stored in the setting parameter storage unit 342a. FIG. 5A shows the state of the original image data stored in the block memory 342b. This Figure 5
As shown in (a), the original image data is 640 dots ×
It is composed of 153600 pixels each consisting of 240 lines. Each of these pixels is RGB (red, green,
Each of (blue) is graded in 32 steps by 5-bit data.

Then, with respect to this original image, a line skip (LineSkip, FIG. 5B) for fetching data every other line according to the parameter set in the setting parameter storage unit 342a is performed every other pixel. Pixel Skip (Figure 5)
(C)), designated start pixel, end pixel, start line, size designation for fetching data in the area surrounded by the end line (FIG. 5 (c)), the horizontal pixel of the original image data is set to 2/3. Then, the translation (FIG. 5 (d)) to be taken in is executed. The image quality is also changed by changing various filter setting values. That is, the color hierarchy of the captured image, the change of the threshold value with respect to the color change, the threshold value of whether or not to consider the same when correlating each block, and the like are changed.

As described above, each parameter for determining the image quality is stored in the setting parameter 342a. The image data compressed according to this parameter is the image data compressed by the image compression unit 342 and the communication control unit 33.
Will be transmitted via. Here, a header indicating which parameter is used for image quality processing is added to each block of the transmitted image data. On the other hand, the videophone on the receiving side reads the header of the received image data, and stores the parameters necessary for the reproduction processing corresponding to the image quality processing performed on the transmitting side in the RAM of the memory 312.

FIG. 6 shows the setting parameter storage unit 3 on the transmitting side.
42 shows the relationship between the parameters stored in 42a and the parameters stored in the RAM of the memory 312 on the receiving side corresponding thereto. The pixel skip setting on the transmission side corresponds to half resolution on the reception side, and the line skip setting on the transmission side is TV mode (TV MODE).
) Is supported. When the pixel skip setting on the transmitting side is “0” (OFF), the half resolution setting on the receiving side is also “0”, and when the pixel skip setting is “1” (ON), half resolution is set. The option setting is also "1". On the other hand, when the line skip on the transmitting side is “0”, the television mode on the receiving side is set to inverted “1”, and when the line skip is “1”, it is also set to inverted “0”. It has become.

By setting the parameters as described above, the thinned image data is compressed and the thinned image data is reproduced in both transmission and reception. For example,
In the case of the setting shown in FIG. 6B, the transmitting side performs pixel skipping and line skipping from the original image for one frame to decimate the image data to 1/4 and capture it, and then compresses and transmits it. . On the other hand, on the receiving side, the image quality is deteriorated by reproducing the image data for one frame in the state of the half resolution “0” and the television mode “1”.

The image quality determined by each parameter may be freely set by the caller according to the designated image quality mode or may be automatically set by the videophone according to the automatic image quality mode. In the designated image quality mode, there are cases where the receiving side of the image data determines the image quality of the other party image to be transmitted, and there are cases where the transmitting side determines the image quality of the own image to be transmitted. When changing the image quality of the image of the other party on the receiving side, the receiving party talker looks at the image of the other party on the display 17 and explains the screen size of the other party image and the image quality of the other party image with reference to FIG. It is specified by the setting of each parameter. That is, line skip, pixel skip, size designation, translation, change of various filter setting values, and the like are designated to designate the image quality of the partner image. When each parameter of the other party image is specified, C
The PU 311 transmits from the communication control unit 33 to the other party's videophone. The central processing unit 31 of the other party's videophone changes the setting parameter storage unit 342a (FIG. 3) to the specified parameter, and thereafter, the compression unit 342c compresses the image data according to the changed parameter.

On the other hand, when the transmitting side changes the image quality of its own image and the self image key of the function key 153 (FIG. 1) is selected, the camera 16 or the VTR 26 is displayed on the display 17 displaying the image of the other party. The self-portrait imaged in is displayed. The caller sets each parameter such as line skip while looking at the self-portrait displayed on the display 17. Each set parameter is stored in the setting parameter storage unit 342a. After that, the compression unit 342c
According to this parameter, block memory 342b
The image data of is captured and compression processing is performed.

C when the automatic image quality mode is set
The PU 311 sets and changes the following parameters. That is, when the compression process is performed to capture one frame of data, and when the data size is small, it is determined that the image has little motion, and each parameter is changed to improve the image quality. On the contrary, when the data size after the compression process becomes large, the parameter is changed so as to reduce the image quality. In this case, for example, if image data is communicated through one ISDN line of 64K [bit / sec], data communication of maximum 8K [byte / sec] is possible. Generally, 4 to 4
Image display of 8 frames is required, and the amount of transmission data per frame needs to be within 1 to 2 K [bytes]. In the present embodiment, if the data amount is 1 K [bytes] or less, the parameters are automatically changed to improve the image quality, and if the data amount is 2 K [bytes] or more, the parameters are automatically changed to reduce the image quality. Thus, it is possible to always approach the transfer rate of 4 to 8 frames per second.

Enlargement / Reduction Processing Next, enlargement / reduction processing according to the gist of the present embodiment will be described. The enlargement and reduction processing can be performed by changing the setting relationship between the transmitting side and the receiving side for the combination of the parameters (a) to (d) on the transmitting side shown in FIG. Enlargement Processing FIG. 7 shows the setting of the parameters of the transmitting and receiving videophones when performing the enlargement processing, and FIG. 8 shows the state of the enlargement processing. As shown in FIG. 7, on the transmission side, both pixel skip and line skip are set to “0” (OFF), and thinning between pixels or lines is not performed, and as shown in FIG. Minute image data, not 1/4 of that
The image data in the area is subjected to image compression processing and transmitted. Here, although thinning out between pixels and between lines is not performed, since only a quarter area is compressed, the amount of image data transmitted is set to "1" for pixel skip and line skip. It is almost the same as when.

On the other hand, on the receiving side, the half resolution is set to "1" and the television mode is set to "0" as shown in FIG. "1" is being performed
The reproduction processing corresponding to the case is performed. As a result, the image data transmitted from the transmission side for the 1/4 area is
On the receiving side, as shown in FIG. 8 (b), the image that has been quadrupled and enlarged to full size image data is displayed on the display 1.
7 will be displayed.

Reduction Processing FIG. 9 shows the setting of the parameters of the transmitting and receiving videophones when the reduction processing is performed.
Indicates the state of reduction processing. As shown in FIG. 9, on the transmitting side, both pixel skip and line skip are set to “1” (ON), and thinning between pixels and lines is performed. Then, as shown in FIG. 10A, image compression processing is performed on the full-size image data for one frame and the image data is transmitted.

On the other hand, on the receiving side, as shown in FIG. 9, the half resolution is set to "0" and the television mode is set to "1". Therefore, for the received image data, pixel skip and line skip are performed. Playback processing corresponding to the case where "0" has not been performed is performed. As a result, the image data transmitted in full size from the transmitting side is displayed on the receiving side as an image reduced to 1/4 as shown in FIG. 10B.

Next, the enlargement / reduction request by the transmitting party and the receiving party will be described. In this embodiment, not only the image enlarged / reduced by the receiver's intention can be displayed on the display 17 of the receiver videophone, but also the enlarged / reduced image can be displayed by the sender's intention. It is possible. That is, when the receiving side caller wants to see the enlargement / reduction screen, the operation key 15 is used to select that fact and to select enlargement / reduction. Then, the video phone on the image receiving side transmits the selected enlargement or reduction request signal to the video phone on the image transmitting side.
When this request signal is received, the video transmission side videophone performs pixel skip and line skip in the setting parameter storage unit 342a for enlargement, as shown in FIG.
It is set to "0" and 1 / as shown in FIG.
The parameter for instructing the compression of the area 4 is set.

On the other hand, when the transmitting speaker wants the other party to see the enlarged image or the reduced image, the operation key 15 is used to select that fact and to select enlargement or reduction. Then, in the videophone on the transmitting side, by setting the parameter added to the header of the image data to be transmitted to a value different from the actual processing, it becomes possible to make the other party see the enlarged or reduced screen. That is, when the enlargement process is selected, the videophone on the image transmitting side captures a 1/4 area of the full-size screen as pixel data and “0” for line skip as image data to be transmitted. Is compressed. Then, the header of this image data is changed to a header indicating that the image data is compressed by pixel skip "1" and line skip "1", and then transmitted. The video telephone on the receiving side reads the changed header, and as shown in FIG. 6B, image reproduction is performed with the half resolution "1" and the television mode "0" set. However, on the transmission side, since the quarter area is compressed by pixel skip and line skip “0”, the compression processing and reproduction parameters have the relationship shown in FIG. 7, and the image reproduced on the reception side is It will be expanded.

When the reduction processing is selected, the videophone on the image transmitting side captures a full-size screen with pixel skips and line skips "1" as image data to be transmitted, and compresses this. Then, the header of this image data is changed to a header indicating that the image data is compressed by pixel skip “0” and line skip “0” and then transmitted. The video telephone on the receiving side reads the changed header, and as shown in FIG. 6A, image reproduction is performed with the half resolution "0" and the television mode "1" set. However, on the transmitting side, the full-size screen is compressed by pixel skipping and line skipping “1”, so both parameters during compression processing and during reproduction have the relationship shown in FIG. 9, and the image reproduced on the receiving side is ,
It will be reduced.

In the embodiment described above, in the enlarging process, the compression process is performed for the 1/4 size of the full size screen and the image is transmitted. However, the present invention is not limited to the 1/4 size. If the size is not larger than the full size when enlarged on the receiving side, 1/5, 1 /
It can be of any size, such as 8. Also, the 1/4 size area on the transmitting side does not have to be the central portion,
It is possible to transmit for any area. The area in this case is designated by the start pixel, the end pixel, the start line, and the end line by the size designation shown in FIG. Further, in the embodiment described above, the vertical and horizontal enlargement / reduction processing of 1/2 is described, but in the present invention, only the relationship between the pixel skip and the half resolution is changed,
It is possible to expand and contract horizontally. Of course, it is also possible to vertically scale up or down by changing only the relationship between the line skip and the television mode.

In the embodiment described above, the DCT is used as an example of the compression processing of the image data by the image processing unit 34, but the present invention is not limited to this method. For example, slope coding, Vector quantization, motion compensation interframe coding, predictive coding, hierarchical vector quantization, FST (Four Square Transform) may be used, or a combination of these may be used for compression processing.

[0056]

According to the videophone of the first aspect, the image data compressed for the predetermined area is received, and the reproduction process is performed assuming that the thinned image data is compressed. As a result, the received image data is enlarged and played back without using a special device.
Can be displayed. According to the video telephone set forth in claim 2, the image data compressed with respect to the thinned image data is received, and the reproduction process is performed assuming that the image data is compressed with respect to the predetermined area. The received pixel data can be reduced and reproduced and displayed without using the device.

[Brief description of drawings]

FIG. 1 is an external configuration diagram of a videophone according to an embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of the videophone of the above.

FIG. 3 is a block diagram showing details of an image processing unit of the above.

FIG. 4 is a flowchart showing an operation of a process during communication of a videophone according to the above.

FIG. 5 is an explanatory diagram conceptually explaining each state of image quality processing.

FIG. 6 is the same as the above, and the parameters stored in the setting parameter storage unit on the transmitting side and the memory 31 on the receiving side corresponding thereto
It is explanatory drawing of the relationship of the parameter stored in 2 RAM.

FIG. 7 is an explanatory diagram of parameters in the transmitting side and receiving side videophones when the enlargement process is performed.

FIG. 8 is an explanatory diagram of a processing state in the enlargement processing of the above.

FIG. 9 is an explanatory diagram of parameters in the transmitting side and receiving side videophones when the reduction processing is performed.

FIG. 10 is an explanatory diagram of a processing state in the reduction processing of the above.

FIG. 11 is a configuration diagram of a conventional videophone that performs image enlargement / reduction processing.

[Explanation of symbols]

 10 videophone 11 base 12 handset 13 display support 14 speaker 15 operation key 16 camera 17 display 18 camera switching key 19 shooting condition switching key 20 color adjustment knob 21 cap 25 VTR connection terminal 31 central processing unit 311 CPU 312 memory 32 ISA bus 33 Communication control unit 34 Image processing unit 341 Image reproducing unit 341a FIFO memory 341b Huffman encoding unit 341c Block memory 341d Compression reproducing unit 342 Image compression unit 342a Setting parameter storage unit 342b Block memory 342c Compressing unit 342d Huffman encoding unit 342e Buffer memory 36 D / A converter 37 Image synthesizer 38 Audio controller

Claims (2)

[Claims] 1. A camera for capturing an image, a first capturing means for capturing image data of a predetermined area from image data of a full size screen captured by the camera, and an image of a full size screen captured by the camera Second capturing means for thinning and capturing data, compression processing for compressing any one of the first capturing means, the image data captured by the second capturing means, and the full-size image data captured by the camera. Means, a transmitting means for transmitting the compressed image data compressed by the compression processing means together with the audio data, a receiving means for receiving the compressed image data and the audio data, and the compressed image data received by the receiving means for compressing the compressed image data. A reproduction processing means for performing reproduction processing according to the state; and a display for displaying the image data reproduced by the reproduction processing means. , Videophone, characterized in that enlarged and reproduced image data received by performing reproduction processing compressed image data for a given region, as being compressed for image data thinned. 2. A camera for capturing an image, a first capturing means for capturing image data of a predetermined area from image data of the full size screen captured by this camera, and an image of the full size screen captured by the camera. Second capturing means for thinning and capturing data, compression processing for compressing any one of the first capturing means, the image data captured by the second capturing means, and the full-size image data captured by the camera. Means, a transmitting means for transmitting the compressed image data compressed by the compression processing means together with the audio data, a receiving means for receiving the compressed image data and the audio data, and the compressed image data received by the receiving means for compressing the compressed image data. The reproduction processing means includes a reproduction processing means for performing reproduction processing according to the state, and a display for displaying the image data reproduced by the reproduction processing means. The compressed image data for the image data drawn, videophone, characterized in that play by reducing the image data received by performing reproduction processing as being compressed for a given area.