JP2522027B2 - Video signal encoding / decoding method and apparatus thereof - Google Patents

Description

The present invention relates to a video conference system, a television monitor,
The present invention relates to a video signal encoding / decoding method and an apparatus thereof for a videophone and the like.

(Prior Art) In a video conference system, an operation such as a specific video camera capturing an image of a conference participant in close-up, and a plurality of video images each having a unique image capturing area when there are a plurality of conference participants.・ There are operations such as switching cameras. However, if there is such an operation,
The correlation between frames of the video signal output from the camera is extremely lowered, and the coding efficiency is lowered to almost the same level as in the case of in-frame, so that the data compression rate is also lowered.

Further, the encoding / decoding device in the conventional video conference system has the same frame transmission rate over the entire area of the video frame, and for example, when transmitting using a line with a transmission rate of 64 kbps or less, the motion of the subject is When it is violent or when the video camera is controlled, the correlation between frames is reduced and sufficient data compression cannot be obtained, which reduces the number of frames that can be transmitted. Since the number of frame replenishments for repeatedly displaying the video is increased and the delay until the decoding of the new scene image is increased, the motion cannot be sufficiently reproduced.

On the other hand, when there is almost no movement of the subject, even though frame supplementation in which the same image is repeatedly displayed can be applied, data compression is efficiently executed by correlation between frames, and the number of frames that can be transmitted is reduced. There was an irrational behavior of maximizing.

FIG. 2 is a block diagram of a conventional encoding / decoding device described as a moving image codec system diagram in FIG. 6 of Oki Electric R & D, Vol.53, No. 4, Volume 2, page 2. The upper half of FIG. 2 shows the coder side, and the lower half shows the decoder side, both of which are connected via a line of 64 kbps and constitute a part of the video conference system. Below, the second
The portion of the drawing related to the present invention will be described.

First, the coder side will be described. The video input is an NTSC signal sent from a video camera that shoots a participant of the video conference system, and is input to the YC separation circuit 1. YC
The separation circuit 1 converts the video signal from the luminance signal Y and the color difference signal R.
-Y, BY are separated, and these are analog / digital (A
/ D) Input to converter 2. The A / D converter 2 converts the luminance signal Y and the color difference signals RY and BY into digital signals and then inputs them to the prefilter 3 to perform preprocessing for encoding. A frame memory (A) 4 is connected to the output side of the prefilter 3.

The frame memory (A) 4 stores the data of the current encoding target frame. In addition to this, a frame memory (B) for storing encoded previous frame data
5 and a background memory 6 for storing background data.

The adaptive vector coding unit 7 uses the data read from the frame memory 4 to predict the intra-frame prediction error of the luminance signal and the chrominance signal or the inter-frame data by the luminance / color difference beltre encoding method using human visual characteristics. The prediction error of is represented by the "quantization vector number" represented by the quantization vector.

The motion vector detection unit 8 divides the screen into a plurality of blocks, and based on the data in the frame memories 4 and 5 and the background memory 6, a motion vector (MV ) ”Is detected, and motion compensation in interframe coding is performed.
At this time, in order to compress the data, the adaptive vector encoding unit 7 uses the data of the previous frame for the block for which the difference between the frames is determined to be smaller than a predetermined threshold value. "Replenishment" is executed and sent. As for the data of the background portion, the data of the background memory 6 may be used instead of the data of the frame memory 5.

The variable length encoding unit 9 encodes the quantized vector number, motion vector, and pixel supplement data, which have been quantized in this way, into a variable length by the Huffman code or the like and stores them in the buffer memory 10.

The transmission control unit 11 reads the data in the buffer memory 10 and manages the entire device, 64 kbps or
It controls the buffer with the 56 kbps digital line, synchronizes with other terminal equipment, and sends it to the other party's decoder via the digital line.

The decoder side has a configuration symmetrical to the coder side as shown in the figure in order to perform the decoding process according to the same promise as the coder side described above, and its operation is clear from the above description.

In this way, if there is little motion of the video conference participants who are to be imaged via the line with the transmission rate of 64 kbps or 56 kbps, a color moving image with a resolution of about 120 lines x 128 pixels will be about 10 per second. It can be transmitted depending on the frame rate.

(Problems to be Solved by the Invention) However, the encoding / decoding device configured as described above is
120 lines x 128 to transmit about 10 frames per second
It is not easy to obtain a resolution higher than that of a pixel, and it has been a limitation to transmit an upper body image of about one or two video conference participants. Regarding the movement, normally, until the new frame data is decoded on the display device side,
In order to perform frame supplement display by repeating the image of the previous frame, it is necessary to transmit a large number of frames when there is a lot of movement, but the correlation between the frames is reduced, so that the data cannot be sufficiently stored. There was a drawback that it was not compressed and the actual movement could not be reproduced properly.

The present invention transmits a redundant frame for an image with a limited resolution or a transferable imaging range of about 1 to 2 persons and a small amount of motion in the conventional encoding / decoding apparatus as described above. , On the contrary, solved the problem that the number of frames that can be transmitted decreases for images with many movements.
An object of the present invention is to provide a video signal encoding / decoding method and an apparatus therefor, which have excellent high resolution and excellent motion expression.

(Means for Solving the Problem) According to the present invention, a video signal obtained by encoding and transmitting a video signal obtained by imaging with a video camera, and decoding and displaying the transmitted video signal. Encoding of
In the decoding method, on the encoding side, an image pickup area of a predetermined size is set within the image pickup area picked up by the video camera, and a code having a constant shape included in the image pickup area and narrower than the image pickup area. And a pre-encoding frame memory that stores the data of the entire imaging region by setting the encoding region in advance to a plurality of positions, selecting the encoding region of one of the plurality of positions according to the region control input, and A current frame memory for storing the data of the video camera in the coding area as data to be coded is provided, and the data of the current frame memory is subjected to interframe coding, and the coded data obtained by the coding Is transmitted together with an area identification code for identifying the position of the encoded area, and the encoded data is encoded by the locally decoded data. The data in the relevant coding area of the frame memory is replaced, the data in the pre-encoding frame memory is used as the previous frame data in the inter-frame coding, and the decoding side stores the data of the entire imaging area. A pre-decoding frame memory is provided, the area identification code and the encoded data transmitted from the encoding side are received, both are separated, and one frame of the separated encoded data is decoded. Each time, the decoded data is stored in the area corresponding to the area identification code of the pre-decoding frame memory, and the data of the pre-decoding frame memory is used as the data of the previous frame for inter-frame decoding, There is provided a video signal encoding / decoding method for displaying a video of only the decoded area.

Further, according to the present invention, in a video signal encoding / decoding device for encoding and transmitting a video signal obtained by imaging of a video camera and decoding and displaying the transmitted video signal, The encoding side is a pre-encoding frame memory that stores data of the entire image capturing area of a predetermined size set within the image capturing range captured by the video camera, and a narrower than the image capturing area and in the image capturing area. Data of the video camera in one coding area selected according to the area control input from the coding areas of a predetermined shape set in advance at a plurality of positions to be included is stored as data to be coded. The current frame memory,
Interframe coding is performed on the data in the current frame memory, the coded data obtained by the coding is transmitted together with a region identification code for identifying the position of the coding region, and the coded data is decoded to obtain An encoding circuit that replaces the data in the relevant encoding area of the pre-encoding frame memory with the locally decoded data and uses the data in the pre-encoding frame memory as the previous frame data in inter-frame encoding. The decryption side is equipped with
A pre-decoding frame memory that stores data of the entire imaging area, and the area identification code and the encoded data sent from the encoding side are received to separate the two, and the separated encoded data Each time one frame is decoded, the decoded data is stored in the area corresponding to the area identification code of the pre-decoding frame memory, and the data of the pre-decoding frame memory is inter-frame decoded. There is provided a video signal encoding / decoding device, which is provided with a decoding circuit used as data of a previous frame and is configured to display a video of only the decoded area.

(Operation) According to the encoding / decoding method and the apparatus thereof of the present invention, even in a video conference system using a line with a transmission speed of 64 kbps or less, the entire imaging area is changed while changing the encoding area. By transmitting, it becomes possible to display an image of a wider area than each coded area.
Further, according to the present invention, since the entire image pickup area, for example, the data of the entire view of the video conference is stored in the previous frame memory, even when the coding area is changed, the correlation between the frames is not lowered. It is possible to realize highly efficient data compression by interframe coding and reduce the delay until a new coded area is decoded.

Further, according to the present invention, in areas where the frame rate is not the same in all areas and in which there is little motion, the same data is displayed by frame supplementation, and only the coded areas in which motion is large are preferentially encoded and transmitted. Therefore, the resolution is increased and the reproducibility of the movement is secured even if a line having a predetermined transmission rate, for example, a transmission rate of 64 kbs or less is used.

(Embodiment) FIG. 1 is a block diagram of an encoding / decoding device showing a first embodiment of the present invention. This encoding / decoding device is roughly divided into an encoding device 200 and a decoding device 300.

First, the encoding device 200 will be described. The video camera 20 captures the participants of the video conference,
The obtained video signal is input to the digitizing circuit 21.

FIG. 3 shows the relationship between the imaging area of the video camera 20 and the coding area. In FIG. 3, 240 indicated by A
An area of line × 320 pixels is a range of an image actually taken by the video camera 20, that is, an imaging area. An area of 120 lines × 160 pixels indicated by B is a range of an image to be encoded, that is, an encoding area, and is set narrower than the imaging area A. Here, although the coding area B is set at substantially the center of the imaging area A, it may be another position having the same size within the range of the setting imaging area A. In FIG. 3, by selecting the setting position of the coding area in units of 20 lines in the vertical direction and 20 pixels in the horizontal direction, 63 setting positions are shown, and the upper left end position of the coding area B is set to 1 respectively.
Indicated by numbers from ~ 63. Hereinafter, these numbers are referred to as area numbers.

Returning to the explanation of FIG. The digitizing circuit 21 digitizes and outputs the video signal including all of the imaging area A from the video camera 20.

The current frame memory 22 has an area corresponding to the coded area B, and the data of the coded area B input from the digitizing circuit 21 will be described below with a write address control circuit 24.
The data is written by the write address signal of, and read as data for encoding and supplied to the encoding circuit 25.

The write timing generating circuit 23 inputs an area number (signal) designating the encoded area B from an appropriate external signal generating means through an area control terminal, and the area number (signal) is inputted.
Specifies one of the area numbers 1 to 63 as the coded area B, the write timing generation circuit 23 informs the write address control circuit 24 of the timing information at which the data of the specified area exists, and the video of the coded area B is displayed. The signal data is stored in the current frame memory 22.

The encoding circuit 25 is configured by, for example, the description of the above-mentioned conventional technique or the technique described in "Oki Electric R & D Vol.53. No. 4".

The encoding circuit 25 transmits the data obtained by highly efficient encoding and compressing the data from the current frame memory 22, together with an area number indicating which encoding area the data is, through the digital line 28, Then, the data is decoded to obtain locally decoded data. The current frame memory 22 is rewritten with the data of this locally decoded value. The data in the current frame memory 22, that is, the locally decoded value, is
It is transferred to the address for the coding area B of the previous frame memory 27. When the encoding is performed while changing the encoding area B, the frame memory 27 is filled with the video data of the entire imaging area. In encoding of two or more frames, the data in the previous frame memory 27 is subjected to interframe encoding, conditional pixel supplementation, and other correlation techniques to obtain correlation between frames and perform data compression.

The address control for data transfer to the previous frame memory 27 and the address control for encoding are performed by the encoding address control circuit.
26 is the area number (signal) input via the area control terminal
Select the coding area according to.

Next, the decoding device 300 will be described. Decoding circuit 3
In 0, the signal received via the digital line 28 is decoded to obtain the data of the coded area and its area number.
The current frame memory 31 writes the decoded data in the coded area.

The decoding address control circuit 32 transfers and writes the data of the coded area to the corresponding area of the previous frame memory 33 as the data of the video area indicated by the decoded area number each time the decoding is completed.

The data written in the previous frame memory 33 is used for interframe decoding as in the case of encoding.

When the encoding device 200 performs encoding while changing the encoding area, the decoding device 300 also includes the previous frame memory 3
Since the data update area 3 is correspondingly changed, the previous frame memory 33 is filled with the video data of the entire imaging area. Therefore, the encoder's previous frame memory 27
The previous frame memory 33 of the decoding device stores the video data of the entire imaging area and is used for inter-frame prediction. The display circuit 34 uses the previous frame memory 33.
The data written in is read out as video data and displayed on the monitor 35.

Since the data of the area wider than the coding area is stored in the previous frame memory 33, the data of the area wider than the coding area is displayed on the monitor 35.

Regarding the selection of the coded area, the operator of the video conference sequentially selects the area numbers 1, 9, 55 and 63 by manual operation to transmit the whole view, and then selects the area centering on the speaker in the conference. Although a method is possible, in order to make selection more quickly, a method of automatically selecting a corresponding area according to the movement of a detected person or a voice, and selection by a remote control from a common partner A method is also possible.

FIG. 4 is a diagram showing a second embodiment of the present invention in which the coding area is selected by manual operation in the coding apparatus 200. Reference numeral 36 is an operation panel installed in front of the person in charge of the video conference (not shown). The control panel 36 is provided with four normal push-button type keys K1, K2, K3, and K4, each of which has upward, downward, left, and right-pointing arrows displayed. Drive circuit 37. The transition circuit 37 outputs the “area number” moved in the arrow direction according to the key K1, K2, K3 or K4. For example, the key
Depending on the number of times K1 is pressed, it changes to the area number above the current position. This area number is input to the encoding device 200 via the area control terminal.

In addition, a superimposing circuit 38 and a coded address control circuit 26 are provided on the output side of the video camera 20 which images the participants of the video conference.
A green frame generation circuit 39 for generating a green frame is provided in the screen displayed on the output side of the. The superposition circuit 38 is used for the video camera 20.
A video signal output from the green frame generation circuit 39 and a green frame signal output from the green frame generation circuit 39 are superimposed and input to the display device 40, and the screen is displayed (shown by the block of the display device 40 in FIG. 4). A square green frame GF in green is displayed on the top, and the region number of the selected coding region is displayed therein. The facilitator performs a manual operation on the operation panel 37 while looking at such a display,
A desired coding area can be easily selected.

FIG. 5 is a diagram showing a third embodiment of the present invention in which the coding area is selected by a manual operation in the decoding circuit 300. 41 is an operation panel having the same configuration as the operation panel 36, 42 is a transition circuit having the same configuration as the transition circuit 37, 43 is a green frame generation circuit 39
The green frame generating circuits 39 and 44 having the same structure as in (1) are superimposing circuits having the same structure as the superimposing circuit 38, and 45 is a display device having the same structure as the display device 40. The operation of the operation panel 41 is displayed in the display operation 45, and the area number output from the transition circuit 42 is transmitted to the encoding device 200 via the digital circuit 28, and the operation similar to the above is performed by this area number. Then, the desired coding area is selected from the decoding device 200 in the form of remote control.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention in which a large motion area is selected as a coding area, and shows a coding apparatus 200. In the encoding device 200, 46
Is a difference circuit for detecting the difference between the current image data output from the digitizing circuit 23 and the current image data stored in the previous frame memory 27 in the corresponding area.
The accumulator circuit 47 receives the difference signal of the difference circuit 46, calculates the sum, and determines the difference signal having the maximum value by the determination circuit, thereby obtaining the coding area having the most movement. Then
The area number corresponding to the coded area having the most movement is fetched from the address control circuit 26 and given to the area control terminal.
With such a configuration, a region centering on the speaker of the video conference can be selected as an encoding region, and a wide image including the periphery thereof can be displayed without sacrificing transmission of heavy image motion. be able to. The surrounding image is, so to speak, area-filled.

FIG. 7 is a diagram showing a fifth embodiment of the present invention in which a coding area is selected by voice. Microphones 48, 49, and 50 are installed on the table TB in front of the speaker. The speaker determination circuit 52 determines the speaker to be selected based on the level difference and the phase shift difference between the voice signals of the microphones 48, 49 and 50. The area number conversion circuit 51 generates an area number of an area centering on the speaker based on the area of the speaker corresponding to the voice signal selected by the speaker determination circuit 52, and supplies the area number to the encoding circuit 25. With such a configuration, video is preferentially transmitted centering on the speaker.

 Next, the effects of the above-described embodiments will be listed.

(A) By changing the coding area, even a video conference system using a line with a transmission speed of 64 kbps or less can display an image in a wider area than each coding area. It can be used for conferences with many participants, and provides a highly realistic image.

(B) Since the entire imaging area can be displayed by changing the coding area, it is easy to include all the participants in the video conference in the imaging area, and such an imaging area is wide. It is not necessary to use a separate camera for capturing the image or to use another encoding device for high resolution still images.

(C) Since the entire image of the imaging region can be transmitted while changing the coding region, when transmitting a still image without motion, a wide region image can be obtained with high resolution, and therefore the still image can be obtained. It can also be used as an encoding / decoding device for a computer.

(D) Since the entire view of the video conference is stored in the previous frame memory in advance, even if the coding region is changed to select the positions of the participants of the other video conference, the correlation between the frames is not lowered, Data can be compressed by highly efficient inter-frame coding, so the delay until the new coded area is decoded does not increase significantly compared to normal video, and image deterioration, unnatural motion, etc. It is possible to reproduce an excellent image without causing

(E) In the case of the conventional encoding / decoding, since the frame rate is the same over the entire area of the video frame, it is sufficient when the movement of the subject is strong or the direction of the camera is controlled. Since data cannot be compressed and the number of frames that can be transmitted is reduced, the frame supplementation for repeatedly displaying the same image on the display device increases and the motion cannot be sufficiently reproduced. Even if there is no frame, frame supplementation in which the same image is repeatedly displayed is allowed, but data compression by interframe correlation is efficiently transmitted, and there is an irrational operation in which the maximum number of frames that can be transmitted is maximized. However, according to the above-described embodiment, the entire video frame area is not transmitted at the same frame rate, but only the coding area having a large motion is preferentially transmitted, and other regions having a small motion are repeated by the same data. By supplementing the area to be displayed and selecting the coding area so that all areas are sequentially transmitted when there is little movement in all areas, the frame rate increases and wastes when there is little movement as in the prior art. It is expected that the unreasonable operation of transmitting the video to the mobile terminal will be improved, and that an image with excellent motion reproducibility can be obtained even when the information to be transmitted is limited.

Further, according to the above-described embodiment, even when implemented in a video conference system using a line with a transmission speed of 64 kbps or less,
Resolutions (number of participants) and frames that were previously unobtainable
You get the rate.

(F) Since the inter-frame coding uses the data of the area wider than the coding area as the data of the previous frame, the response at the time of changing the coding area is fast, and the entire area is not displayed. The effect is large even if only is displayed.

(Effect of the Invention) As described in detail above, in the present invention, on the encoding side, interframe encoding is performed on the data of one encoding area of a plurality of encoding areas narrower than the imaging area. A pre-encoding frame in which encoded data obtained by encoding is transmitted together with an area identification code for identifying the position of the encoding area, and the data of the entire imaging area is stored by locally decoded data obtained by decoding the encoded data. -The data in the relevant coding area of the memory is replaced, and the data in this pre-encoding frame memory is used as the previous frame data in inter-frame encoding. At the decoding side, it is sent from the encoding side. Each time the received area identification code and encoded data are received, the two are separated, and one frame of the separated encoded data is decoded, the decoded data Is stored in the area corresponding to the area identification code of the pre-decoding frame memory that stores the data of the entire imaging area, and this pre-decoding frame memory data is used as the previous frame data for inter-frame decoding. .

That is, in the present invention, the information of the area outside the coding area (data of the previous frame) is also used as prediction information for inter-frame coding and decoding. As a result, even when the movement of the subject is large (for example, when a new area selection equivalent to camera pan is electronically performed), deterioration in image quality and deterioration in reproducibility of movement due to deterioration in encoding characteristics are reduced. . This means that the response at the time of changing the coding area becomes faster, and it is very effective especially when displaying only the decoded video corresponding to the coding area without displaying the entire area.

Further, if the data in the area outside the coded area is transmitted when the motion of the subject is small and the coding efficiency is high, the distribution of the data to be transmitted can be rationalized. That is, it is rational that data for prediction is sent at the time of video transmission with a sufficient transmission capacity, and this prediction data is contributed to the improvement of coding efficiency when there is not enough transmission capacity such as when changing the coding area. It becomes possible to perform an operation.

Further, according to the present invention, since the coded area can be electronically controlled, simple coded area control can be performed by voice, movement, or operation of the other party.

[Brief description of drawings]

FIG. 1 is a block diagram of a coding / decoding device showing an embodiment of the present invention, FIG. 2 is a block diagram of a conventional coding / decoding device, and FIG. 3 is a relationship between an imaging region and a coding region. FIG. 4, FIG. 5, FIG. 6, FIG. 6 and FIG. 7 are block diagrams showing the second, third, fourth and fifth embodiments of the present invention, respectively. 22,31 …… Current frame memory, 25 …… Encoding circuit, 27,33 …… Previous frame memory, 30 …… Decoding circuit, 34 …… Display circuit, 36,41 …… Control panel, 46… … Difference detection circuit, 47 …… Judgment circuit, 48, 49, 50 …… Microphone.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-84689 (JP, A) JP-A-52-32620 (JP, A) JP-A-59-21186 (JP, A) Special table Sho-56- 500157 (JP, A)

Claims (10)

(57) [Claims] 1. A video signal encoding / decoding method for encoding and transmitting a video signal obtained by picking up an image by a video camera, and decoding and displaying the transmitted video signal. On the encoding side, an imaging region of a predetermined size is set within the imaging range captured by the video camera, and a plurality of coding regions of a fixed shape included in the imaging region and narrower than the imaging region are set in advance. While setting it to the position,
A pre-encoding frame memory that stores the data of the entire imaging region and a data of the video camera in the encoding region is selected by selecting the encoding region of one of the plurality of positions according to the region control input. A region for identifying the position of the coding region by providing a current frame memory for storing as data to be coded, performing interframe coding on the data of the current frame memory, and coding the data obtained by the coding The data in the relevant coding area of the pre-encoding frame memory is replaced with the locally-decoded data obtained by decoding the encoded data and decoding the encoded data, and the data in the pre-encoding frame memory is framed. It is used as the data of the previous frame in inter-coding, and on the decoding side, the data of the entire imaging area is stored before decoding. A ram memory is provided, the area identification code and the encoded data transmitted from the encoding side are received, and both are separated, and each time one frame of the separated encoded data is decoded, The decoded data is stored in the area corresponding to the area identification code of the pre-decoding frame memory, the data of the pre-decoding frame memory is used as the data of the previous frame of the inter-frame decoding, and the data is decoded. A video signal encoding / decoding method characterized in that an image of only an area is displayed. 2. The encoding / decoding of a video signal according to claim 1, wherein the area control input for selecting an encoding area is a signal output from a manually operated operation panel on the encoding side. Method. 3. The encoding / coding of a video signal according to claim 1, wherein the area control input for selecting an encoding area is a signal output according to a voice of a speaker detected on the encoding side. Decryption method. 4. The encoding of a video signal according to claim 1, wherein the area control input for selecting an encoding area is a signal output according to an area judged to have a large motion on the encoding side. -Decryption method. 5. The encoding / coding of a video signal according to claim 1, wherein the area control input for selecting an encoding area is a signal output from an operation of an operation panel provided on a decoding side. Decryption method. 6. A video signal coding / decoding apparatus for coding and transmitting a video signal obtained by imaging of a video camera, and decoding and displaying the transmitted video signal, wherein the coding side is A pre-encoding frame memory that stores data of the entire imaging area having a predetermined size set within the imaging area captured by the video camera; and a frame memory that is narrower than the imaging area and is included in the imaging area. A current frame for storing the data of the video camera in one coding area selected according to the area control input from the coding areas of a predetermined shape preset in a plurality of positions as the data to be coded. Inter-frame coding is performed on the data of the memory and the current frame memory, and the coded data obtained by the coding is used to identify the position of the coding area. Data of the pre-encoding frame memory is replaced by the locally decoded data obtained by decoding the encoded data and replacing the data of the pre-encoding frame memory with the data of the pre-encoding frame memory. An encoding circuit used as data of a previous frame in inter-frame encoding is provided, and the decoding side is a pre-decoding frame memory that stores data of the entire imaging region, and is transmitted from the encoding side. Each time the area identification code and the encoded data are received and separated, and one frame of the separated encoded data is decoded, the decoded data is stored in the pre-decoding frame memory. It is stored in the area corresponding to the area identification code,
And a decoding circuit that uses the data in the memory as the data of the previous frame for inter-frame decoding, and is configured to display an image of only the decoded area. Decoding device. 7. The encoding / decoding of a video signal according to claim 6, wherein the area control input for selecting an encoding area is a signal output from a manually operated operation panel on the encoding side. apparatus. 8. The encoding / coding of a video signal according to claim 6, wherein the area control input for selecting an encoding area is a signal output according to a voice of a speaker detected on the encoding side. Decoding device. 9. A difference detecting means for detecting a difference between current imaged data and data of a previous frame memory corresponding to the imaged data, and a maximum value of the difference detected by the difference detecting means. 7. The video signal according to claim 6, further comprising: a determination unit that determines the coding region of the above, and the region control input that selects the coding region corresponds to the determination output of the determination unit. Encoding / decoding device. 10. The encoding / coding of a video signal according to claim 6, wherein the area control input for selecting an encoding area is a signal output from an operation of an operation panel provided on the decoding side. Decoding device.