JP2003032684A - Image coding device and image coding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form still image coding data in addition to moving image coding data with less hardware resources. SOLUTION: When inter-image coding processing is performed, reference image signals S11 are successively written into an image memory 112 via a switch 111, and compensation of the motion of the image is performed by using the reference image S11 and an input image S10 as with a normal case. On the contrary, when intra-image coding processing is performed, writing of the signals S11 into the image memory is stopped by the switch 111. As described above, the reference image S11 which is subjected to an intro-image coding is not stored in the memory 112, but the reference image S11 which is not subjected to the intra-image coding is stored and retained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image coding apparatus and an image coding method, and can be applied to, for example, a videophone and a mobile terminal device.

[0002]

2. Description of the Related Art Conventionally, as a method of encoding a moving image used in a videophone or the like, a method using intra-image correlation and inter-image correlation has been mainly used. As an encoding method using these, ITU-T Recommendation H.264 is used. Encoding methods such as H.261, H.263, MPEG1, MPEG2, and MPEG4 are known.

On the other hand, in a device such as a videophone, it may be desired to add coded data of a still image to coded data of a moving image for transmission. As this type of device, for example, Japanese Patent Laid-Open No. 11-
There is one described in Japanese Patent Publication No. 98482.

As shown in FIG. 7, this type of video telephone apparatus sends an input image signal S1 picked up by a camera 1 to a moving picture image coding section 4 of an image coding apparatus 3 via a switch 2. At the same time, it is sent to the still image coding unit 6 via the switch 5. Here, the moving image coding unit 4
Performs inter-picture coding processing and intra-picture coding processing on the input image signal S1 to reduce temporal redundancy and spatial redundancy of the image. Further, the still image image encoding unit 6 reduces the spatial redundancy of the image by performing the intra-image encoding process on the input image signal S1.

The moving picture coded data S2 formed by the moving picture picture coding section 4 and the still picture coded data S3 formed by the still picture picture coding section 6 are multiplexed / transmitted via a multiplexer 7. 8 is sent. The transmission data S4 which has been subjected to the multiplexing and the predetermined modulation processing by the multiplexing / transmission unit 8 is sent to the game station 9 through the line.

The game 9 has an image decoding device, and sends the moving image data and still image data decoded by the image decoding device to the monitor device 10. This allows the user to see both moving images and still images on the monitor device 10.

[0007]

However, in the above-described conventional image encoding device 3, the moving image image encoding unit 4 is used.
Since the two encoding units of the still image encoding unit 6 are required, there is a drawback that the configuration becomes large.

When one encoder for moving images is switched to form both moving image encoded data and still image encoded data, only moving image encoded data is formed. Compared with the case, it is necessary to have an extra resource in use, especially an area for a prediction reference image, and there is a drawback that the amount of hardware increases correspondingly.

The present invention has been made in view of the above points, and an image encoding apparatus and an image encoding method capable of forming still image encoded data in addition to moving image encoded data with a small amount of hardware resources. The purpose is to provide.

[0010]

In order to solve such a problem, the present invention applies an inter-image coding process and an intra-image coding process to an input image signal, and when performing an inter-image coding process, the input is performed. In the image coding apparatus configured to code the difference value between the image signal and the motion-compensated reference image signal, and to code the input image signal when performing the intra-picture coding process, An encoding unit for encoding,
A local decoding unit that forms a reference image signal by decoding the output of the encoding unit, an image memory that stores the reference image signal, and a motion of the image is predicted based on the stored reference image signal and the input image signal. A configuration is provided that includes a motion compensation unit that compensates the motion of the reference image according to the motion of the reference image, and a writing control unit that controls the stop of writing the reference image signal to the image memory when performing the intra-picture coding process. .

According to this structure, when the moving image encoded data is formed, that is, when the inter-image encoding process is performed, the reference image signals are sequentially written in the image memory by the write control means, and the reference image is generated. The image motion compensation using the input image is performed as usual. On the other hand, when the still image encoded data is formed, that is, when the intra-image encoding process is performed, the writing control unit stops writing the reference image signal in the image memory. As a result, the image encoded reference image is not stored in the image memory,
A reference image that has not been subjected to intra-image coding processing is stored and held. Accordingly, when the moving image coding process is performed next, the moving image coding process can be performed using the reference image previously stored in the image memory as it is.
Thus, it is possible to realize an image encoding device capable of performing both moving image encoding and still image encoding while suppressing an increase in hardware resources.

Further, according to the present invention, inter-picture coding processing and intra-picture coding processing are performed on an input picture signal, and when the inter-picture coding processing is performed, the input picture signal and the motion-compensated reference picture signal are used. In the image encoding device configured to encode the difference value of the image signal and to encode the input image signal when performing the intra-image encoding process, an encoding unit that encodes the image signal, and the encoding unit. A local decoding unit that forms a reference image signal by decoding the output of the unit, an image memory that stores the reference image signal, and a reference image that predicts the motion of the image based on the stored reference image signal and the input image signal. Is provided with a motion compensating unit for compensating for the motion according to the motion, and a decoding control unit for turning off the decoding operation of the local decoding unit when performing the intra-picture coding process.

According to this structure, when the moving image encoded data is formed, the reference images decoded by the local decoding unit are sequentially stored in the image memory, and the motion of the image using the reference image and the input image is moved. Compensation will be applied as usual.
On the other hand, when forming still image encoded data, the local decoding unit is turned off to stop writing the reference image signal to the image memory. As a result,
The reference image that has been subjected to the intra-picture coding process is not stored in the image memory, and the reference image that has not been subjected to the intra-picture coding process is stored and held. As a result, when the moving image coding process is performed next, the moving image coding process can be performed using the reference image previously stored in the image memory as it is. Thus, it is possible to realize an image encoding device capable of performing both moving image encoding and still image encoding while suppressing an increase in hardware resources. Further, since the local decoding unit does not operate when forming still image coded data, power consumption can be reduced accordingly.

Further, according to the present invention, the inter-picture coding processing and the intra-picture coding processing are performed on the input picture signal, and when the inter-picture coding processing is performed, the input picture signal and the motion-compensated reference picture signal are used. In the image encoding device configured to encode the difference value of the image signal and to encode the input image signal when performing the intra-image encoding process, an encoding unit that encodes the image signal, and the encoding unit. A local decoding unit that forms a reference image signal by decoding the output of the unit, an image memory that stores the reference image signal, and a reference image that predicts the motion of the image based on the stored reference image signal and the input image signal. Is provided at the input stage of the image coding apparatus for performing motion compensation according to the motion of the image coding apparatus and is capable of repeatedly outputting the input image. An image output means for outputting the same image, when an image in the coding process, employs a configuration which includes a write control means for stopping controlling the writing of the reference image signal to the image memory.

According to this configuration, the reference image that has been subjected to the intra-picture coding process is not stored in the image memory, and the reference image that has not been subjected to the intra-picture coding process is stored and held. When performing the moving image coding process next time, the moving image coding process can be performed using the reference image previously stored in the image memory as it is, and thus the increase of the hardware resources can be suppressed to a low level to reduce the moving image. Both image coding and still image coding can be performed. In addition to this, since the image input / output unit is provided, the same image as the moving image encoded can be encoded as a still image. As a result, the image encoding with a simpler configuration with further improved convenience A device can be realized.

According to the present invention, the inter-image coding process and the intra-image coding process are performed on the input image signal, and when the inter-image coding process is performed, the input image signal and the motion-compensated reference image signal are used. In the image encoding method, which encodes the difference value of the image signal and also encodes the input image signal when performing the intra-image encoding process, the encoding step of encoding the image signal, and the encoding step. A local decoding step of forming a reference image signal by decoding the output formed by the step, a reference image writing step of writing the reference image signal in a predetermined image memory, a stored reference image signal and an input image signal The motion compensation step of predicting the motion of the image based on the motion compensation of the reference image according to the motion, and the reference image signal to the image memory when the intra-picture coding To have a writing control step of stopping the write.

According to this method, when the moving image encoded data is formed, the reference image signal is sequentially written in the image memory in the encoding step, and the image using the reference image and the input image is formed. Motion compensation is applied as usual. On the other hand, when forming still image encoded data, writing of the reference image signal to the image memory is stopped in the writing control step. As a result, the reference image that has been subjected to the intra-picture coding process is not stored in the image memory, and the reference image that has not been subjected to the intra-picture coding process is stored and held. As a result, when the moving image coding process is performed next, the moving image coding process can be performed using the reference image previously stored in the image memory as it is. Thus, it is possible to realize an image coding method capable of performing both moving image coding and still image coding while suppressing an increase in hardware resources.

According to the present invention, the inter-image coding process and the intra-image coding process are performed on the input image signal, and when the inter-image coding process is performed, the input image signal and the motion-compensated reference image signal are used. In the image encoding method, which encodes the difference value of the image signal and also encodes the input image signal when performing the intra-image encoding process, the encoding step of encoding the image signal, and the encoding step. A local decoding step of forming a reference image signal by decoding the output formed by the step, a reference image writing step of writing the reference image signal in a predetermined image memory, a stored reference image signal and an input image signal The motion compensation step of predicting the motion of the image based on the motion compensation and the motion compensation of the reference image according to the motion, and the decoding operation of the local decoding unit when performing intra-picture coding To have a local decoding stop controlling.

According to this method, when forming the moving image encoded data, the reference images decoded in the local decoding step are sequentially stored in the image memory, and the motion of the image using the reference image and the input image is moved. Compensation will be applied as usual. On the other hand, when forming still image coded data, the local decoding unit is turned off in the local decoding stop step to stop the writing of the reference image signal to the image memory. As a result, the reference image that has been subjected to the intra-picture coding process is not stored in the image memory, and the reference image that has not been subjected to the intra-picture coding process is stored and held. As a result, when the moving image coding process is performed next, the moving image coding process can be performed using the reference image previously stored in the image memory as it is. Thus, it is possible to realize an image coding method capable of performing both moving image coding and still image coding while suppressing an increase in hardware resources. Also, since the local decoding step is not executed when forming still image encoded data,
The power consumption can be reduced accordingly.

According to the present invention, the inter-image coding process and the intra-image coding process are performed on the input image signal, and when the inter-image coding process is performed, the input image signal and the motion-compensated reference image signal are used. In the image encoding method, which encodes the difference value of the image signal and also encodes the input image signal when performing the intra-image encoding process, the encoding step of encoding the image signal, and the encoding step. A local decoding step of forming a reference image signal by decoding the output formed by the step, a reference image writing step of writing the reference image signal in a predetermined image memory, a stored reference image signal and an input image signal The motion compensation step of predicting the motion of the image based on the motion compensation of the reference image according to the motion, and the reference image signal to the image memory when the intra-picture coding A write control step of stopping the write, when an image in the encoding process, so that a step of selecting a re the same image as the coding object in the encoding step.

According to this method, the reference image subjected to the intra-picture coding process is not stored in the image memory, and the reference image not subjected to the intra-picture coding process is stored and held. When performing the moving image coding process next time, the moving image coding process can be performed using the reference image previously stored in the image memory as it is, and thus the increase of the hardware resources can be suppressed to a low level to reduce the moving image. Both image coding and still image coding can be performed. Further, by having the step of selecting the same image again as an encoding target in the encoding step, it is possible to encode the same image as the moving image encoded as a still image, resulting in further improvement of convenience. The image coding method described above can be realized.

The recording medium of the present invention has a structure in which a program for executing any of the above image coding methods is recorded.

The image transmission apparatus of the present invention has a configuration including any one of the above image encoding apparatuses.

According to this configuration, it is possible to realize an image transmission apparatus capable of performing both moving image coding and still image coding while suppressing an increase in hardware resources.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The gist of the present invention is to stop writing to an image memory for a reference image used when forming moving image encoded data when encoding a still image. As a result, the present invention is able to favorably perform image coding processing for both moving images and still images without increasing hardware resources.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 shows an image coding apparatus according to Embodiment 1 of the present invention. In FIG. 1, the image encoding device 100 is configured to be capable of forming compressed moving image encoded data by performing inter-image encoding processing using a motion-compensated reference image, and
Still image coded data can be formed by performing the intra-image coding process.

The image coding apparatus 100 receives the input image signal S10 picked up by the camera 101 from the image coding unit 102.
To enter. The image encoding unit 102 forms the image encoded data D1 by sequentially transmitting the difference data output from the difference circuit 103 to the orthogonal transform circuit 104, the quantization circuit 105, and the variable length encoding circuit 106.

The image coding apparatus 100 also has a local decoding unit 107. The local decoding unit 107 performs inverse quantization processing and inverse orthogonal transformation processing on the quantized data output from the quantization circuit 105 by the inverse quantization circuit 108 and the inverse orthogonal transformation circuit 109, respectively. The decoded data obtained by the inverse orthogonal transform circuit 109 is sent to the adder circuit 110. In the adder circuit 110, the inverse orthogonal transform circuit 109
And the output of the motion compensation circuit 114 are added.

The output of the adder circuit 110 is supplied to a reference image signal S11 via a switch circuit 111 as a write control means.
Is stored in the image memory 112 as Image memory 11
The reference image signal S11 read from No. 2 is supplied to the motion prediction circuit 113 and the motion compensation circuit 114. The motion prediction circuit 113 predicts the amount of motion of an image by comparing the input image signal S10 with a reference image signal S11 that is an image one frame before this image by a method such as block matching, for example. To do.

The motion compensation circuit 114 includes an image memory 112.
Motion compensation is performed by moving the reference image read from the motion estimation circuit 113 by the motion amount predicted by the motion prediction circuit 113.
This motion compensation result is sent to the difference circuit 103. The difference circuit 103 calculates the difference between the input image and the motion-compensated image, and sends the calculation result to the quantization circuit 105. As described above, in the image encoding device 100, the temporal redundancy of images is reduced by performing the inter-image encoding process.

The image coding apparatus 100 also inputs the coded image data D1 output from the variable length coding circuit 106 to the coded data output selection circuit 115. The encoded data output selection circuit 115 selectively outputs the encoded image data D1 to the multiplexing / transmission unit 202 or the storage memory 203 as a data storage unit based on a selection control signal from the system control unit 201 of the image transmission device 200. Send out.

In the case of this embodiment, when the image coded data D1 is coded data subjected to inter-picture coding processing, the coded data output selection circuit 115 codes the coded data as a moving image. It is sent to the multiplexing / transmission unit 202 as data D2. On the other hand, the encoded data output selection circuit 115 stores the encoded data as still image encoded data D3 in the storage memory when the image encoded data D1 is the encoded data subjected to the intra-image encoding process. 20
Send to 3.

The still image data D3 stored in the storage memory 203 is sent to the multiplexing / transmission unit 202 or the image decoding device 204 in response to a request. The still image decoded by the image decoding device 204 is displayed on the monitor 205 of the own station. Further, when the image transmission apparatus 200 receives a request from the game 206 to view a moving image, the multiplexing / transmission unit 20
2 from the video encoded data D to the game 206 via the line
2 is sent out. On the other hand, when there is a request to the image transmission apparatus 200 from the game 206 to view a still image, the multiplexing / transmission unit 202 reads the still image coded data D3 from the storage memory 203, and reads it. 206
Send to.

In the above configuration, the image encoding device 10
When the control signal indicating that the moving image coding process is performed is input from the system control unit 201, the coding control unit 116 of 0 sends a control signal for instructing the inter-image coding process to the image coding unit 102. At the same time, a switching control signal indicating that the switch circuit 111 is turned on is transmitted. At this time, since the reference images for motion compensation are sequentially written in the image memory 112, the image encoding device 100 performs the inter-image encoding process satisfactorily using this reference image to obtain the moving image encoded data. D2 may be formed.

On the other hand, when the coding control unit 116 of the image coding apparatus 100 receives a control signal indicating that the still image coding process is to be performed from the system control unit 201, the image coding unit 102 receives the image. A control signal for instructing the inner encoding process is transmitted, and a switching control signal indicating that the switch circuit 111 is turned off is transmitted.

As a result, the image memory 112 does not store the reference image that has been subjected to the intra-picture coding process, but stores and holds the reference image that has not undergone the intra-picture coding process. Accordingly, when the moving image coding process is performed next, the moving image coding process can be performed using the reference image previously stored in the image memory 112 as it is.

When the user wants to see a still image,
By reading the still image encoded data D3 stored in the storage memory 203, the user can view the still image at any time.

Thus, according to the above configuration, the image coding apparatus 100 capable of performing both moving image coding and still image coding while suppressing an increase in hardware resources.
Can be realized.

(Embodiment 2) FIG. 2 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals shows an image coding apparatus according to a second embodiment of the present invention.

The image encoding device 300 includes a local decoding unit 3
The operation of 02 is controlled to be turned on / off. Specifically, the local decoding unit 302 operates when the control signal S20 instructing the ON operation is input from the encoding control unit 301 serving as the decoding control means, and stops when the control signal S20 instructing the OFF operation is input. .

In practice, the image coding apparatus 300 turns on the decoding operation of the local decoding unit 302 when performing the inter-picture coding process. On the other hand, the image encoding device 300 controls the decoding operation of the local decoding unit 302 to be off when performing the intra-image encoding process.

In the above configuration, the image coding device 30
When the control signal indicating that the moving image coding process is performed is input from the system control unit 201, the coding control unit 301 of 0 sends a control signal instructing the inter-image coding process to the image coding unit 102. Together with local decoding unit 302
To the control signal S20 for instructing the ON operation. At this time, the reference images for motion compensation are sequentially written in the image memory 112, so that the image encoding device 3
00 can use this reference image to perform good inter-image coding processing.

On the other hand, when the coding control unit 301 of the image coding apparatus 300 receives a control signal indicating that a still image is to be coded from the system control unit 201, the image coding unit 102 receives an intra-image control signal. The control signal instructing the encoding process is transmitted and the control signal S20 indicating the off operation is transmitted to the local decoding unit 302.

As a result, the image memory 112 does not store the reference image subjected to the intra-picture coding process, but stores and holds the reference image not subjected to the intra-picture coding process. Accordingly, when the moving image coding process is performed next, the moving image coding process can be performed using the reference image previously stored in the image memory 112 as it is.

Thus, according to the above configuration, the image coding apparatus 300 capable of performing both moving image coding and still image coding while suppressing an increase in hardware resources.
Can be realized. Further, since the local decoding unit 302 is not operated when forming the still image coded data D3, the power consumption can be reduced accordingly.

(Third Embodiment) FIG. 3 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals shows an image coding apparatus according to a third embodiment of the present invention.

The image coding apparatus 400 uses the input image signal S
An input selection unit 402 serving as an image input / output unit in the input stage 10
Is provided. The input selection unit 402 is the encoding control unit 4
The input input image signal S10 can be repeatedly output based on the control signal from 01. Here, the input selection unit 402 may be composed of, for example, an image memory and a notification mechanism for notifying an image update.

In the above configuration, the image coding device 40
0 turns off the switch circuit 111 when there is an instruction to switch the processing from the moving picture coding processing to the still picture coding processing. At this time, the input selection unit 402 again outputs the same image as the image output as the last encoding target for the moving image encoding process, as an image for the still image encoding process. Then, in the image encoding device 400, the re-output image is subjected to intra-image encoding processing to form still image encoded data D3.

Therefore, the still image-encoded image is the same as the last moving image-encoded image. As a result, the same image as the image to be transmitted as a moving image to the game 206 can be periodically stored in the storage memory 203. Thus, for example, when the user on the side of the game 206 wants to see the image once viewed as a moving image on the monitor 207 as a still image again, the corresponding still image stored in the storage memory 203 can be read out. Good.

According to the above configuration, by providing the input selection unit 402, in addition to the effects obtained in the first and second embodiments, the same image as the moving image coded still image is obtained. As a result, it is possible to realize the image encoding device 400 having a simple structure with further improved convenience.

(Embodiment 4) FIG. 4 in which parts corresponding to those in FIGS. 2 and 3 are assigned the same reference numerals shows an image coding apparatus according to a fourth embodiment of the present invention.

The image coding apparatus 500 includes a coding control unit 5
The local decoding unit 3 based on the control signal S20 from 01.
The operation of No. 02 is controlled to be turned on / off, and an input selection unit 402 capable of repeatedly outputting the input image signal S10 is provided.

As a result, the image coding 500 can perform both moving image coding and still image coding while suppressing an increase in hardware resources, and at the same time, the same image as the moving image coded still image can be captured. It can also be encoded as a picture. As a result, it is possible to realize the image encoding device 500 having a simple structure with improved convenience.

(Fifth Embodiment) FIG. 5 in which parts corresponding to those in FIG. 1 are assigned the same reference numerals shows an image coding apparatus according to a fifth embodiment of the present invention.

The image coding apparatus 600 has an input selecting section 602 as an input image selecting means. In the case of this embodiment, the image signal decoded by the image decoding apparatus 204 is input to the input selection unit 602 in addition to the input image signal S10 from the camera 101. Incidentally, in the image decoding device 204, according to the connection position of the switch circuit 604,
Either the moving image coded data D2 output from the multiplexing / transmission unit 202 or the still image coded data D3 stored in the storage memory 203 is input.

The input selection unit 602 sends either the input image signal S10 or the output of the image decoding device 204 to the image encoding unit 102 as the next encoding target image based on the selection signal from the encoding control unit 601. . Thereby, in the image encoding device 600, moving image encoding and still image encoding processing can be independently performed on a plurality of input images. For example, an image input separately from an image encoded as a moving image can be encoded as a still image.

According to the above configuration, in addition to the effect obtained in the first embodiment, it is possible to realize the image encoding device 600 having a simple configuration with further improved convenience.

(Sixth Embodiment) FIG. 6 in which parts corresponding to those in FIGS. 2 and 5 are assigned the same reference numerals shows an image coding apparatus according to a sixth embodiment of the present invention. The image encoding device 700 is
The operation of the local decoding unit 302 can be controlled to be turned on / off based on the control signal S20 from the encoding control unit 701, and an input selection unit 602 for inputting and selectively outputting a plurality of images is provided. Have.

As a result, the image coding apparatus 700 can perform both moving image coding and still image coding while suppressing an increase in hardware resources, and at the same time, moving images can be independently moved for a plurality of input images. Encoding and still image encoding processing can be performed. As a result, it is possible to realize the image encoding device 700 having a simple structure with improved convenience.

(Other Embodiments) In the above embodiment, the local decoding units 107 and 302 perform dequantization based on the quantized image data supplied from the image coding unit 102. As mentioned above, the image encoding unit 1
The image coded data D1 output by 02 may be variable-length decoded and the result may be inversely quantized.

In the above-described embodiment, the case where the local decoding units 107 and 302 generate the reference image based on the image data after motion compensation supplied from the image encoding unit 102 has been described. Is not limited to this,
The local decoding units 107 and 302 may directly generate the next reference image based on the reference image in the image memory 112.

In the above embodiment, the case where the still image data D3 is stored in the storage memory 203 has been described, but the moving image coded data D2 may be stored in the storage memory 203. . Alternatively, both data may be stored in the storage memory 203. Further, it may be possible to directly send to the image decoding apparatus 204 without using the storage memory 203.

In the above-described embodiment, the case where there is only one type of still image coded data D3 has been described, but the present invention is not limited to this, and a plurality of still image coded data D3 can be obtained by changing the output. It is also possible to adopt a configuration for outputting Further, the encoded data output selection circuit 11
5 has a structure in which the moving image coded data D2 and the still image coded data D3 are separately output, but the data can be indexed and output from the same output means.

Further, in the above-mentioned embodiments, the image coding apparatus 100, 200, 300, 40 according to the present invention.
Although the case where the 0, 500, 600, 700 and the image coding method are realized by hardware has been described, the present invention is not limited to this, and can be realized by software, and further, the software is read from a recording medium in which the software is recorded. It is also possible to realize the present invention.

The present invention further relates to a signal processor (DS
It can also be incorporated into various electronic devices as the image encoding device in P). Further, the present invention can be incorporated in a mobile terminal device and can be realized as a mobile communication system having this mobile terminal.

[0067]

As described above, according to the present invention,
By stopping the writing to the image memory for the reference image used when forming the moving image encoded data when encoding the still image, moving image encoded data can be converted with less hardware resources. In addition, it is possible to realize an image encoding device and an image encoding method capable of forming still image encoded data.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an image encoding device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an image encoding device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an image encoding device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an image encoding device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an image encoding device according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an image encoding device according to a sixth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a conventional image encoding device.

[Explanation of symbols]

100, 200, 300, 400, 500, 600, 7
00 image coding device 102 image coding unit 107, 302 local decoding unit 111 switch circuit 112 image memory 115 coded data output selection circuit 116, 301, 401, 501, 601, 701 coding control unit 200, 303, 403, 503, 603, 703 image transmission device

Claims (8)

[Claims] 1. An inter-image coding process and an intra-image coding process are performed on an input image signal, and when performing the inter-image coding process, a difference between the input image signal and a motion-compensated reference image signal. In an image coding apparatus configured to code the input image signal when performing the intra-image coding process while coding the value, a coding unit that codes the image signal, and the coding unit. A local decoding unit that forms a reference image signal by decoding the output of, an image memory that stores the reference image signal, and a reference image that predicts the motion of the image based on the stored reference image signal and the input image signal. It is characterized by comprising a motion compensating unit for compensating the motion according to the motion, and a writing control unit for controlling the writing of the reference image signal to the image memory when performing the intra-picture coding process. Image encoding device. 2. An inter-image coding process and an intra-image coding process are performed on an input image signal, and when the inter-image coding process is performed, a difference between the input image signal and a motion-compensated reference image signal. In an image coding apparatus configured to code the input image signal when performing the intra-image coding process while coding the value, a coding unit that codes the image signal, and the coding unit. A local decoding unit that forms a reference image signal by decoding the output of, an image memory that stores the reference image signal, and a reference image that predicts the motion of the image based on the stored reference image signal and the input image signal. An image coding apparatus comprising: a motion compensating unit for compensating for the motion according to the motion, and a decoding control unit for turning off the decoding operation of the local decoding unit when performing intra-picture coding processing. . 3. An inter-image coding process and an intra-image coding process are performed on an input image signal, and when performing the inter-image coding process, a difference between the input image signal and a motion-compensated reference image signal. In an image coding apparatus configured to code the input image signal when performing the intra-image coding process while coding the value, a coding unit that codes the image signal, and the coding unit. A local decoding unit that forms a reference image signal by decoding the output of, an image memory that stores the reference image signal, and a reference image that predicts the motion of the image based on the stored reference image signal and the input image signal. A motion compensation unit that compensates for motion according to the motion, and a motion compensation unit that is provided at the input stage of the image coding apparatus and can output the input image repeatedly. An image code comprising: an image input / output unit for outputting one image; and a writing control unit for controlling the writing of the reference image signal to the image memory when performing intra-image coding processing. Device. 4. An inter-image coding process and an intra-image coding process are performed on an input image signal, and when the inter-image coding process is performed, a difference between the input image signal and a motion-compensated reference image signal. A coding step of coding an image signal in the image coding method adapted to code the input image signal when the value is coded and the intra-picture coding process is carried out, and the coding step. A local decoding step of forming a reference image signal by decoding the output formed by, a reference image writing step of writing the reference image signal into a predetermined image memory, and a stored reference image signal and an input image signal. A motion compensation step of predicting a motion of an image based on the motion and compensating a reference image according to the motion; and the reference to the image memory when performing the intra-picture coding process. Picture coding method characterized by comprising a write control step of stopping the writing of the image signal. 5. An inter-image coding process and an intra-image coding process are performed on an input image signal, and when the inter-image coding process is performed, a difference between the input image signal and a motion-compensated reference image signal. A coding step of coding an image signal in the image coding method adapted to code the input image signal when the value is coded and the intra-picture coding process is carried out, and the coding step. A local decoding step of forming a reference image signal by decoding the output formed by, a reference image writing step of writing the reference image signal into a predetermined image memory, and a stored reference image signal and an input image signal. A motion compensation step of predicting the motion of an image based on the motion of the reference image according to the motion, and a decoding operation of the local decoding unit when performing intra-picture coding processing. Picture coding method characterized by comprising a local decoding termination step for full control. 6. An inter-image encoding process and an intra-image encoding process are performed on an input image signal, and when the inter-image encoding process is performed, a difference between the input image signal and a motion-compensated reference image signal. A coding step of coding an image signal in the image coding method adapted to code the input image signal when the value is coded and the intra-picture coding process is carried out, and the coding step. A local decoding step of forming a reference image signal by decoding the output formed by, a reference image writing step of writing the reference image signal into a predetermined image memory, and a stored reference image signal and an input image signal. A motion compensation step of predicting a motion of an image based on the motion and compensating a reference image according to the motion; and the reference to the image memory when performing the intra-picture coding process. An image characterized by comprising: a writing control step of stopping writing of an image signal; and a step of selecting the same image again as an encoding target in the encoding step when performing the intra-image encoding processing. Encoding method. 7. A recording medium on which a program for executing the image coding method according to any one of claims 4 to 6 is recorded. 8. An image transmission device comprising the image coding device according to claim 1. Description: