JPH06339132A - Coding decoding method and device for motion picture - Google Patents

Abstract

PURPOSE:To inform the outline of a picture and to realize a system offering excellent picture quality even under a small transmission capacity by displaying a coded picture similar to an input picture in the coding and decoding of a motion picture. CONSTITUTION:A characteristic quantity extract circuit 12 extracts a parameter being a characteristic quantity of an input picture 101. A comparator circuit 13 compares the extracted parameter 103 with plural reference parameters 104 to provide an output of a reference control signal 106 or a coded control signal 105. A picture coding circuit 11 uses the coded control signal 105 to code the input picture 101 to send coded data 102. A parameter memory 14 uses the coded control signal 105 to record the extract parameter 103 and outputs plural recorded reference parameters 104. A coded data memory 15 records the coded data 102 and uses a reference selection signal 106 to selectively output reference data 107 from the recorded data. A picture decoding circuit 16 decodes the coded data 102 or the reference data 107 to output an output picture 108.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture coding / decoding method and apparatus.

[0002]

2. Description of the Related Art In the prior art, it has been common to perform moving picture coding / decoding using motion-compensated interframe prediction processing. As an example, the CCITT international standardized moving picture coding / decoding method H.264 is used. In step 261, the input image is divided into blocks of 16 pixels and 16 lines, and the motion-compensated inter-frame prediction is executed in block units using the reference image. As the reference image, a decoded image obtained by decoding the last transmitted image encoded data inside the encoding device is used. The auxiliary information used for the motion compensation inter-frame prediction and the error signal for the prediction are encoded and transmitted.

Further, in the "image communication system" described in Japanese Patent Laid-Open No. 62-068384, element parts constituting a subject such as a face and arms are extracted from an input image, and standard part data and extracted parts held in a database in advance are extracted. The difference is encoded and transmitted as a characteristic parameter. On the decoding side, a plurality of standard partial data are transformed with the parameters and combined to synthesize a reproduced image.

[0004]

The conventional motion-compensated interframe prediction method H.264. At 261, the auxiliary information used for motion compensation and the prediction error signal are encoded and transmitted to the decoding side. For this reason, when the transmission capacity is small, there is a problem that the encoded data cannot be transmitted sufficiently and the decoded image is significantly deteriorated, or the frame rate of the decoded image is significantly reduced. In addition, JP-A-62-0683
In the "image communication method" described in Japanese Patent Publication No. 84, the extracted parameters are coded and transmitted, so that it can be realized with a small transmission capacity, but since the standard partial data prepared in advance is transformed to obtain the reproduced image, the input image is subtly different There was a problem that it could not express various features and became an artificial and unnatural image.

An object of the present invention is to analyze a current input image, compare it with a plurality of input images coded and decoded in the past to determine whether or not to code the input image, and perform the coding. If it is determined, the information for selecting the most similar past input image in the comparison is transmitted to the decoding side, and the decoding side decodes and displays the encoded data of the encoded input image and holds the record. Incidentally, when the selection information is received, the corresponding one is selected from the held encoded data and is decoded and displayed, so that an image similar to the input image can be displayed with a good image quality even when the transmission capacity is small. It is an object of the present invention to provide a moving image coding / decoding method and device that can be decoded and played back in.

[0006]

According to the present invention, in a moving picture coding / decoding method, at the time of coding, a feature amount of an input image is extracted as a parameter, and the extracted parameter is specified by an instruction of a coding control signal. Record and hold, and output the plurality of previously recorded parameters as reference parameters, compare the extracted parameters with the plurality of reference parameters and select the reference parameter with the highest similarity, and select the maximum similarity. Depending on the value, either the encoded control signal is output or the reference control signal is output to the decoding side, the input image is encoded according to the instruction of the encoded control signal, and decoded as encoded data. Output to the encoding side, and upon decoding, input either the encoded data or the reference control signal for each input image from the encoding side. Either one of the encoded data and the reference data is recorded and held, or one of the plurality of encoded data recorded in the past is selected and output as reference data according to an instruction of the reference control signal. Is decoded and output as an output image.

According to the present invention, in a moving picture coding / decoding apparatus, the coding apparatus records and holds means for extracting a feature amount of an input image as a parameter, and the extracted parameter according to an instruction of a coding control signal, And a means for outputting the plurality of recorded parameters as reference parameters in the past, and comparing the extracted parameters with the plurality of reference parameters to select the reference parameter having the highest degree of similarity to obtain the value of the highest degree of similarity. In accordance with the means for either outputting the encoding control signal or transmitting a reference control signal to the decoding side, and encoding the input image according to the instruction of the encoding control signal, and decoding as encoded data And a means for transmitting the encoded data or the reference control signal for each of the input images. Means for receiving and recording the encoded data, or selecting one from the plurality of encoded data recorded in the past according to the instruction of the reference control signal and outputting it as reference data; Or a unit for decoding one of the reference data and outputting it as an output image.

Further, in the present invention, in the moving picture coding / decoding method, at the time of coding, the feature quantity of the input picture is extracted as a parameter, and the extracted parameter is recorded and held by an instruction of a coding control signal, and The plurality of parameters recorded in the past are output as reference parameters, the extracted parameters are compared with the plurality of reference parameters, and the reference parameter having the highest similarity is selected, and the reference parameter is selected according to the value of the maximum similarity. Either output the encoded control signal or output the reference control signal to the decoding side, encode the input image according to the instruction of the encoding control signal, and output it as encoded data to the decoding side. ,
The difference between the extracted parameter and the selected reference parameter is output to the decoding side as a synthesis parameter, and at the time of decoding, either the encoded data or the reference control signal is encoded for each input image. From the plurality of encoded data held by the reference control signal and output as reference data, and the encoded data or the reference data. Is decoded and output as a decoded image, and the output image is combined and output from the decoded image using the combining parameter.

According to the present invention, in a moving picture coding / decoding apparatus, the coding apparatus records and holds a means for extracting a feature amount of an input image as a parameter, and the extracted parameter according to an instruction of a coding control signal. And a means for outputting the plurality of recorded parameters as reference parameters in the past, and comparing the extracted parameters with the plurality of reference parameters to select the reference parameter having the highest similarity, and the maximum similarity value. Means for performing either one of outputting the encoding control signal or transmitting a reference control signal to the decoding side, and encoding the input image in accordance with the instruction of the encoding control signal to obtain encoded data. And a means for transmitting to the decoding side as a decoding, and decoding the difference between the extracted parameter and the selected reference parameter as a combined parameter The decoding device receives either the encoded data or the reference control signal from the encoding side for each of the input images, and records or retains the encoded data. Means for selecting one from the plurality of encoded data according to the instruction of the reference control signal and outputting it as reference data, and means for decoding either the encoded data or the reference data and outputting it as a decoded image, Means for synthesizing and outputting an output image from the decoded image using the synthesizing parameter.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first moving picture coding / decoding method and apparatus of the present invention will be described with reference to FIG.

FIG. 1 is a block diagram of an embodiment of an apparatus for realizing the first moving picture coding / decoding method of the present invention.

This moving picture coding / decoding apparatus has a feature quantity extraction circuit 1 for extracting a feature quantity of an input image as a parameter.
2 and a parameter memory 14 which records and holds the extracted parameters according to an instruction of an encoding control signal and outputs the previously recorded parameters as reference parameters.
And comparing the extracted parameters with the plurality of reference parameters to select the reference parameter having the highest degree of similarity, and outputs the encoded control signal or decodes the reference control signal according to the value of the highest degree of similarity. It is composed of a comparison circuit 13 for performing either transmission to the encoding side, and an image encoding circuit 11 for encoding the input image according to an instruction of the encoding control signal and transmitting it as encoded data to the decoding side. And a coded data memory 15 for recording and holding the received coded data or selecting one of the recorded coded data according to an instruction of the reference control signal and outputting the selected coded data as reference data. , A decoding device including an image decoding circuit 16 for decoding the encoded data or the reference data and outputting the decoded image as an output image.

The operation of this embodiment will be described. Here, on the premise that a plurality of images selected from a series of past input images 101 have already been encoded / decoded, the operation of the encoding / decoding process on the current input image 101 will be described.

On the encoding side, first, the feature amount extraction circuit 12 analyzes the input image 101 and extracts the parameter 103 which is the feature amount of the image. An example of the extraction parameter 103 is shown in FIGS. 3A, 3B, and 3C, and each of them will be described.

[0015] (a) in FIG. 3 is an input image I (t at time t _{i
In this example, the} subject area is extracted from _i ) and the central coordinate position g _i and the inclination θ _{i of the} main axis are used as the parameters. In this case, first, a closed region in the input image with little change in brightness or hue is extracted and regarded as one subject region. Next, the average value of the coordinate positions of the pixels forming the subject area is calculated and defined as g _i . Further, the principal axis of the subject area is calculated and the inclination of the image with respect to the vertical axis is defined as θ _i . In the example of FIG. 3B, a subject region is extracted from the input image I (t _i ) at time t _i , and a plurality of feature points (p _i , q _i , r _i , s _i ) on the contour line of the subject region are extracted. In this example, the coordinate position of is used as a parameter. In this case, the contour line of the subject region extracted from the input image by the above method is approximated to a polygon, and each vertex of the polygon is defined by a feature point (p _i ,
q _i , r _i , s _i ). FIG. 3C is an example that can be used when the input image is known in advance as a face image. The entire face and the eyes and mouths are extracted from the input image I (t _i ) at time t _i , and the face is extracted. The central coordinate position f _i of the part and the values (er _i , el _i , m _i ) indicating the open / closed states of the eyes and mouth are used as extraction parameters. In this case, first, an elliptical area having a flesh color hue is extracted as a face portion from the input image,
The central coordinate position is defined as f _i . Further, the relative position roughly predict the position of the eyes or mouth from the relationship, the portion of each eye and mouth area brightness and hue are different from the surrounding in the vicinity of the predicted positions of the f _i in the face portion To extract. Eyes and mouth of the opening and closing states vertical size of the value of the portion of the extracted _{(er i, el i, m} i)
It is represented by. Any one of the plurality of parameters described above or a combination of the plurality of parameters is used as the extraction parameter 103.

The comparison circuit 13 compares the extraction parameter 103 with a plurality of reference parameters 104 supplied from the parameter memory 14 and selects the reference parameter having the highest degree of similarity. In the selection, the absolute value of the difference between the two parameters to be compared is used as the difference coefficient, and the smaller the value of the coefficient, the higher the similarity. Further, when the parameter is a set of a plurality of elements, the value obtained by weighting and adding the absolute difference values for each element is used as the difference coefficient. The weighting ratio may be uniform, or a feature point having a high possibility of erroneous detection such as a feature point of the outline contour of the subject is reduced, and a feature point having a low possibility of erroneous detection such as the coordinate position of the center of the region is increased. Alternatively, if the input image is a face image and the extraction parameters consist of multiple elements of different types, the weighting of the elements related to eye and mouth movements should be increased in order to detect changes in facial expressions more accurately. Good.

The comparison circuit 13 compares the difference coefficient in the selected parameter with a predetermined threshold value, and outputs either the reference control signal 106 or the coding control signal 105 according to the determination result. Specifically, when the difference coefficient is smaller than a predetermined threshold value, the data selection corresponding to the selected parameter is used as the reference selection signal 106.
To the decoding side. The data index also corresponds to the encoded data 102 obtained by encoding the original input image of the selected parameter on a one-to-one basis. When the reference selection signal 106 is output, the current input image 10
The encoding process for 1 is completed. On the other hand, when the difference coefficient is larger than a predetermined threshold value, the reference selection signal 106 is not output, but the encoding control signal 105 for instructing the encoding of the current input image 101 and the record retention of the extraction parameter is output. To do. That is, if the current input image 101 is similar to a specific image coded and decoded in the past,
The current input image 101 is transmitted only when a simple signal for instructing to display the similar image on the decoding side is transmitted, and the similar image is not found in the past encoding history.
It encodes itself and sends it to the decoding side. The threshold value may be set to a fixed value prior to a series of encoding / decoding processes, or may be variable according to the intensity of fluctuations in the extraction parameter. As a specific example, the parameter extracted from the input image of the previous frame is held inside the comparison circuit 13 with a delay, and the absolute value dp between frames of this and the extracted parameter of the current input image is used as a proportional coefficient, The threshold Th may be updated for each image frame by the expression Th = (dp / dn) × Th (init). Where dn, Th
(Init) is a value determined in advance prior to a series of encoding / decoding processes.

The image coding circuit 11 uses the coding control signal 10
According to the instruction of No. 5, the current input image 101 is encoded and the encoded data 102 is transmitted to the decoding side. As the encoding process, an image encoding system defined by ISO / JPEG as an international standard can be used. Specifically, the input image 101 is divided into blocks of a predetermined size,
Discrete cosine transform, quantization, and zigzag scan transform are performed for each block, and replaced with a variable length code to obtain the encoded data 102. Further, when the input images which are temporally close to each other are continuously encoded, the C described in the prior art is used.
CITT. 261 or the like can be used. Specifically, the last transmitted coded data is decoded by a local decoding device inside the image coding circuit 11 and held in a memory, and the decoded image is used as a reference image for motion compensation interframe prediction code. Run on the current input image.

The parameter memory 14 additionally records the current extraction parameter 103 in accordance with the instruction of the encoding control signal 105. The recording corresponds to recording and holding as history information that the current input image 101 is encoded and transmitted to the decoding side. The parameter memory 14 records and holds the parameters extracted for each of the plurality of input images that have been code-decoded in the past, and outputs these as a plurality of reference parameters 104. When it is difficult to add the parameter memory 104 due to the additional recording, an appropriate one of the parameters already recorded is deleted, and the extracted parameter 103 is newly recorded additionally. The selection of the parameter to be deleted is performed by using the history selected as the optimum reference parameter in the comparison circuit 13 by the method described above. Specifically, the comparison circuit 13 records the selected time for each reference parameter, and deletes the parameter having the oldest selected last time. Alternatively, the selected number may be accumulated for each reference parameter in a plurality of frame periods up to the present, and the parameter having the smallest selected number may be deleted.

On the decoding side, the encoded data 102 received by the encoded data memory 15 is recorded and held. The received encoded data 102 is directly supplied to the image encoding circuit 16. On the other hand, when the reference selection signal 106 is received instead of the encoded data 102, the encoded data memory 15 selects one of the plurality of encoded data recorded and held and which the reference selection signal 106 indicates. It is selected and output as reference data 107. In addition, when the coded data memory 15 is already full and it is difficult to perform additional recording during the recording and holding, one of the plurality of coded data that has already been recorded is deleted and a new one is newly added. The encoded data 102 is additionally recorded. The method of selecting the encoded data to be deleted uses the same method as the method of selecting the parameter to be deleted in the parameter memory 14 described above. Also, the maximum number of coded data that can be recorded and held is the same as the maximum number of parameters that can be registered in the parameter memory 14 described above. With the above settings, the update of the record in the encoded data memory 15 and the update of the record in the parameter memory 14 on the encoding side can be automatically realized in synchronization.

The image decoding circuit 16 decodes any one of the supplied encoded data 102 or reference data 107 and outputs an output image 108 for display reproduction.

The series of encoding / decoding processes described above can also be realized by the configuration example shown in FIG. Figure 4
The moving picture coding / decoding apparatus includes a feature quantity extraction circuit 42 for extracting a feature quantity of an input image as a parameter, a record of the extracted parameter according to an instruction of a coding control signal, and a plurality of past input images. Parameter memory 4 for outputting the extracted parameter as a reference parameter in
4, the extracted parameter is compared with the plurality of reference parameters to select the reference parameter having the highest similarity, and the coding control signal is output or the reference control signal is output according to the value of the maximum similarity. From a comparison circuit 43 that performs either one of transmission to the decoding side, and an image encoding circuit 41 that encodes the input image according to an instruction of the encoding control signal and transmits the encoded image as encoded data to the decoding side. An encoding device configured, an image decoding circuit 46 that decodes a series of the received encoded data to generate a decoded image and outputs the decoded image as an output image for display and reproduction, and records and holds the decoded image. And when not receiving the encoded data, the image memory 4 which selects one of the held decoded images according to the instruction of the reference control signal and outputs it as an output image. It is composed of a.

In the example of FIG. 4, the coding side outputs the coded data 402 of the input image and the reference control signal 406 by the same method as described above with reference to FIG. On the decoding side, the image decoding circuit 46 decodes the encoded data 402 and outputs the decoded image 407. At the same time, the decoded image 407 is also output as an output image 408 for display reproduction.

The image memory 45 records and holds the decoded image 407. Further, when the reference control signal 406 is received instead of the encoded data 402, the image memory 45 selects the reference selection signal 406 from among the plurality of decoded images recorded and held.
Is selected and output as an output image 408 for display and reproduction. In addition, when holding the record,
If the image memory 45 is already full and it is difficult to perform additional recording, one of the already recorded plural decoded images is deleted and a new decoded image 407 is additionally recorded. The method of selecting the decoded image to be deleted uses the same method as the method of selecting the parameter to be deleted in the parameter memory 44. Also, the maximum number of decoded images that can be recorded and held is the same as the maximum number of parameters that can be registered in the parameter memory 44 described above. With the above setting, the update of the record of the image memory 45 and the update of the record of the parameter memory 44 on the encoding side can be automatically realized in synchronization with each other.

Next, an embodiment of the second moving picture coding / decoding method and apparatus of the present invention will be described with reference to FIG. Figure 2
FIG. 1 is a block diagram of an embodiment of an apparatus for realizing a moving picture coding / decoding method of the present invention.

This moving picture coding / decoding apparatus has a feature quantity extraction circuit 2 for extracting a feature quantity of an input image as a parameter.
2, a parameter memory 24 that records and holds the extracted parameters according to an instruction of an encoding control signal, and outputs the plurality of previously recorded parameters as reference parameters, and the extracted parameters as the plurality of reference parameters. A comparison circuit for comparing and selecting the reference parameter having the highest similarity and either outputting the encoded control signal or transmitting the reference control signal to the decoding side according to the value of the maximum similarity. 23, an image encoding circuit 21 that encodes the input image according to the instruction of the encoding control signal, and transmits the encoded image to the decoding side as encoded data, and obtains a difference between the extracted parameter and the selected reference parameter. An encoding device including a differentiator 25 that transmits to the decoding side as a synthesis parameter, and the received encoded data Encoded data memory 2 for output as a reference from a plurality of encoded data the recording by an instruction of the reference control signal or recorded held selects one data
6, an image decoding circuit 27 that decodes either the encoded data or the reference data and outputs the decoded image, and an image that deforms and combines the decoded image using the combination parameter to output the output image It is composed of a decoding device including a synthesizing circuit 28.

The operation of this embodiment will be described. Here, on the premise that a plurality of images selected from a series of past input images 201 have already been encoded / decoded, the operation of the encoding / decoding process on the current input image 201 will be described.

On the encoding side, first, the feature amount extraction circuit 22 analyzes the input image 201 and extracts the parameter 203 which is the feature amount of the image. As the extraction parameter 203, the parameters described above in the examples of FIGS. 3A, 3B, and 3C are used in combination.

The comparison circuit 23 compares the extracted parameter 203 with a plurality of reference parameters 204 supplied from the parameter memory 24 and selects the reference parameter having the highest degree of similarity. Further, the comparison circuit 23 compares the difference coefficient between the extracted parameter 203 and the selected parameter with a predetermined threshold value, and outputs either the reference control signal 206 or the coding control signal 205 according to the determination result. Specifically, when the difference coefficient is smaller than a predetermined threshold value, the data index corresponding to the selected parameter is transmitted to the decoding side as the reference selection signal 206.
The data index also has a one-to-one correspondence with the encoded data 202 obtained by encoding the original input image of the selected parameter.
Correspond. On the other hand, when the difference coefficient is larger than a predetermined threshold value, the reference selection signal 206 is not output, and the encoding control signal 205 for instructing the encoding of the current input image 201 and the record holding of the extraction parameter 203 is output. Output.
The threshold value may be set to a fixed value prior to a series of encoding / decoding processes, or may be variable according to the intensity of fluctuations in the extraction parameter.

The difference calculator 25 obtains the difference between the extraction parameter 203 and the selected reference parameter, and sends the difference as the synthesis parameter 207 to the decoding side. Specifically,
If the extraction parameter is the center coordinate position g _i of the subject area and the inclination θ _{i of the} main axis as in the example of (a) of the above, the difference (d (g _i ), d () between the optimum reference parameters g _z and θ _z θ _i )) = (g _i −g _z , θ _i −θ
_z ) is the difference parameter 207. Further, as shown in the example of FIG. 3B, the extraction parameter is a plurality of feature points (p
_i , q _i , r _i , s _i ), the difference (d (p _i ), d (q _i ), d (r) from the optimum reference parameter (p _z , q _z , r _z , s _z ). _i ), d (s _i ))
_{= (P i -p z, q} i -q z, r i -r z, s i -
Let s _z ) be the difference parameter 207. Alternatively, FIG. 3 (c)
If the extraction parameter is a value (f _i , er _i , rl _i , m _i ) that represents the state of the local part of the subject region, as in the example above, the optimum reference parameter (f _z , er _z , e)
l _z, m _z) and of the difference _{(d (f i), d} (er i), d (el i), d
( _{M i} )) = (f _i −f _z , er _i −er _z , _{e i} −
el _z, and m _i -m _z) difference parameter 207. When the comparison circuit 23 does not output the reference control signal 206, the above-mentioned transmission of the synthesis parameter 207 is not performed. The image encoding circuit 21 receives the current input image 20 according to the instruction of the encoding control signal 205.
1 is encoded and the encoded data 202 is transmitted to the decoding side.

The parameter memory 24 additionally records the current extraction parameter 203 in accordance with the instruction of the encoding control signal 205. The parameter memory 24 records and holds the parameters extracted for each of the plurality of input images that have been code-decoded in the past, and outputs these as a plurality of reference parameters 204. When it is difficult to add the parameter memory 204 due to the additional recording, an appropriate one of the parameters already recorded is deleted, and the extracted parameter 203 is newly recorded additionally. The parameter to be deleted is selected by using the history selected by the comparison circuit 23 as the optimum reference parameter by the method described above. Specifically, the comparison circuit 23 records the selected time for each reference parameter, and deletes the parameter with the oldest time selected last. Alternatively, the selected number may be accumulated for each reference parameter in a plurality of frame periods up to the present, and the parameter having the smallest selected number may be deleted.

On the decoding side, the encoded data 202 received by the encoded data memory 26 is recorded and held. The received encoded data 202 is directly supplied to the image encoding circuit 27. On the other hand, when the reference selection signal 206 is received instead of the encoded data 202, the encoded data memory 26 selects one of the plurality of encoded data recorded and held and which the reference selection signal 206 indicates. It is selected and output as reference data 208. In addition, when the coded data memory 26 is already full and additional recording is difficult at the time of recording and holding, one of the plurality of coded data already recorded is deleted and a new one is newly added. The encoded data 202 is additionally recorded. The method of selecting the encoded data to be deleted uses the same method as the method of selecting the parameter to be deleted in the parameter memory 24 described above. Further, the maximum number of coded data that can be recorded and held is the same as the maximum number of parameters that can be recorded in the parameter memory 24 described above. With the above settings, the update of the record in the encoded data memory 26 and the update of the record in the parameter memory 24 on the encoding side can be automatically realized in synchronization with each other.

The image decoding circuit 27 decodes any one of the supplied coded data 202 or reference data 208 and outputs a decoded image 209.

The image synthesizing circuit 28 uses the received synthesizing parameter 207 to perform deformation synthesizing processing on the decoded image 209 and outputs it as an output image 210 for display and reproduction. Specifically, as described above using the example of FIG. 3A, if the synthesis parameter 207 is the center coordinate position of the subject region and the displacement amounts d (g _i ) and d (θ _i ) of the inclination of the main axis, For example, the parallel movement of d (g _i ) and the rotational movement of d (θ _i ) around the front center position g _i are performed for each pixel constituting the subject area. Further, as described above with reference to the example of FIG. 3B, the combined parameters 207 are displacement amounts d (p _i ), d (g _i ), d (r _i ) of coordinate positions of a plurality of feature points in the subject area. ),
If d (s _i ), the parallel movement represented by the following equation is performed for each pixel forming the subject area.

(Lp × d (p _i ) + lq × d (q _i ) +
lr × d (r _i ) + ls × d (s _i )) / (lp + lq
+ Lr + ls) where (lp, lq, lr, ls) is a coefficient that is inversely proportional to the distance between the pixel of interest and each of the feature points (p _i , q _i , r _i , s _i ). Alternatively, as described above using the example of FIG. 3C, the combined parameter 207 is the displacement amount d (f _i ), d (er _i ), d in the state of the local portion of the subject region.
If (el _i ) and d (m _i ), the moving and transforming processing is executed for each area corresponding to the element of the parameter.

The series of encoding / decoding processes described above can also be realized by the configuration example shown in FIG. Figure 5
The moving picture coding / decoding apparatus according to the present invention stores a feature quantity extraction circuit 52 for extracting a feature quantity of an input image as a parameter, a record of the extracted parameter according to an instruction of the coding control signal, and a plurality of past inputs. A parameter memory 54 that outputs the extracted parameter as a reference parameter in an image, selects a reference parameter having the highest similarity by comparing the extracted parameter with the plurality of reference parameters, and selects the reference parameter according to the value of the maximum similarity. And outputs the encoded control signal or transmits a reference control signal to the decoding side, and a comparator circuit 53, which encodes the input image according to an instruction of the encoded control signal to obtain encoded data. An image coding circuit 51 to be transmitted to the decoding side, and a difference between the extracted parameter and the selected reference parameter is obtained and combined. An image decoding device configured to include a differentiator 55 that transmits to the decoding side as a parameter, and a decoded image that is generated by decoding the received series of encoded data and outputs the decoded image as an output image for display reproduction. And an image to output the decoded image as a reference image by selecting one of the plurality of decoded images stored in accordance with an instruction of a reference control signal when the decoded image is recorded and held and the encoded data is not received. It comprises a memory 57 and an image synthesizing circuit 58 for transforming and synthesizing the reference image using the received synthesizing parameter to generate an output image and outputting the image for display and reproduction.

In the example of FIG. 5, on the encoding side, the encoded data 502 of the input image, the reference control signal 506, and the synthesis parameter 5 are processed in the same manner as described above with reference to FIG.
07 is output. On the decoding side, the image decoding circuit 56 decodes the encoded data 502 and outputs a decoded image 508. At the same time, the decoded image 508 is output as an output image 510 for display reproduction.

The image memory 57 records and holds the decoded image 508. Further, when the reference control signal 506 is received instead of the encoded data 502, the image memory 57 selects the reference selection signal 506 from among the plurality of decoded images that are recorded and held.
Select one of them and output it as a reference image 509. In addition, when the image memory 57 is already full and it is difficult to perform additional recording in the record holding, one of the plurality of decoded images already recorded is deleted to newly add the decoded image. 508 is additionally recorded. The method of selecting the decoded image to be deleted uses the same method as the method of selecting the parameter to be deleted in the parameter memory 54.
The maximum number of decoded images that can be recorded and held is also the same as the maximum number of parameters that can be recorded in the parameter memory 54 described above. With the above settings, the recording of the image memory 57 is updated and the parameter memory 54 on the encoding side is updated.
It can be automatically realized by synchronizing with the update of the record.

The image synthesizing circuit 58 uses the received synthesizing parameter 507 to transform and synthesize the reference image 509 and outputs it as an output image 510 for display and reproduction.

Further, in the example of FIG. 5, the comparison circuit 5 on the encoding side is used.
3, a plurality of reference parameters similar to the current extraction parameter 503 may be selected and a plurality of reference control signals 506 and synthesis parameters 507 may be transmitted. In this case, on the decoding side, the reference control signal 50 is sent from the image memory 57.
A plurality of reference images 509 designated by No. 6 are read out, and one image 510 is synthesized by the image synthesizing circuit 58 using the synthesis parameter 507 and output. An example of the operation when the plurality of reference parameters are selected will be described with reference to FIG.

In the example of FIG. 6, parameters extracted from a plurality of past input images are held in the parameter memory in advance as reference parameters. Current input image I (t
Parameters extracted with _{c) P (t c) =} (f c, e
r _c , el _c , m _c ) with said reference parameters,
Parameters P (t ₁ ) and P similar to P (t _c ).
Select (t ₂ ) and P (t ₃ ). This selection result is shown in Figure 5.
The reference control signal 506 is transmitted to the decoding side. For each element of the current extraction parameter, the one most similar to the selected plurality of reference parameters is selected and Sel (t
_c ). Specifically, as compared with the current input image I (t _c ), the parameter f1 of the image I (t ₁ ) is selected at the center coordinate position of the face portion, and the eye condition is the parameter of the image I (t ₃ ). (Er ₃ , el ₃ ) is selected, and the state of the mouth is the parameter m ₂ of the image I (t ₂ ). Further, since the above-mentioned f _c and f ₁ are simple values representing the coordinate position, the difference is obtained and set as Dif (f _c ). Sel (t _c ) and Dif
It is transmitted to the decoding side as the synthesis parameter 507 of FIG. 5 together with (f _c ). On the decoding side, the three reference images D (t ₁ ), D (t ₂ ), D (t ₃ ) are read from the image memory 57 by the reference control signal 506 in FIG. Here, D (t ₁ ), D (t ₂ ), and D (t ₃ ) are decoded images obtained by coding and decoding the input images I (t ₁ ), I (t ₂ ), and I (t ₃ ), respectively. . The image synthesizing circuit 58 synthesizes _one image from the three reference images D (t ₁ ), D (t ₂ ), D (t ₃ ) using the synthesizing parameter 507, and outputs it as an output image 510. To do. Specifically, the entire face portion is extracted from the reference image D (t ₁ ), and the portions of both eyes and the reference image D cut out from the reference image D (t ₃ ) are extracted.
The output portion 510 is composed by overlapping the mouth portions cut out from (t ₂ ).

[0042]

As described above, according to the present invention, the characteristic amount of an image encoded in the past is held as history information on the encoding side, and the series of encoded data received is stored on the decoding side. If there is a history of coded decoding of a similar image in the past with respect to a new input image, only a control signal for selecting the similar image is transmitted, and the decoding side holds the same. The similar image is displayed as it is or after being transformed and combined. Therefore, when there is little change between frames on the input image, or when similar input images reappear after a certain frame period, the image quality is excellent and similar to the input image with only a small amount of data transmission. The natural image can be displayed on the decoding side.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a first moving image coding / decoding system of the present invention.

FIG. 2 is a basic configuration diagram of a second moving image coding / decoding system of the present invention.

FIG. 3 is a diagram illustrating an example of a feature amount of an image.

FIG. 4 is a configuration diagram of an embodiment for realizing a first moving image coding / decoding system of the present invention.

FIG. 5 is a configuration diagram of an embodiment for realizing a second moving image coding / decoding system of the present invention.

[Fig. 6] Fig. 6 is a diagram for explaining an embodiment of a second moving image coding / decoding system of the present invention.

[Explanation of symbols]

 11, 21, 41, 51 Image coding circuit 12, 22, 42, 52 Feature amount extraction circuit 13, 23, 43, 53 Comparison circuit 14, 24, 44, 54 Parameter memory 15, 26 Coded data memory 16, 27 , 45, 56 Image decoding circuit 25, 55 Difference device 28, 58 Image combining circuit 46, 57 Image memory 101, 201, 401, 501 Input image 102, 202, 402, 502 Encoded data 103, 203, 403, 503 Extraction parameter 104, 204, 404, 504 Reference parameter 105, 205, 405, 505 Encoding control signal 106, 206, 406, 506 Reference control signal 107, 208 Reference data 108, 210, 408, 510 Output image 207, 507 Composite Parameter 209, 407, 508 Decoded image 50 Reference image

Claims (4)

[Claims] 1. A method for encoding / decoding a moving image, wherein at the time of encoding, a characteristic amount of an input image is extracted as a parameter, the extracted parameter is recorded and held by an instruction of an encoding control signal, and is previously recorded. Outputting a plurality of recorded parameters as reference parameters, comparing the extracted parameters with the plurality of reference parameters to select the reference parameter having the highest degree of similarity,
Either output the encoded control signal or output a reference control signal to the decoding side according to the value of the maximum similarity, encode the input image according to an instruction of the encoded control signal, Output as encoded data to the decoding side, and at the time of decoding, input either the encoded data or the reference control signal from the encoding side for each input image, and record and hold the encoded data. In the past, one of the plurality of recorded encoded data is selected according to the instruction of the reference control signal and is output as reference data, and either the encoded data or the reference data is decoded and output as an output image. A method for encoding / decoding a moving image, characterized by: 2. A moving image coding / decoding apparatus, wherein the coding apparatus extracts a feature amount of an input image as a parameter, records the extracted parameter according to an instruction of an encoding control signal, and stores the past parameter. A means for outputting the plurality of recorded parameters as a reference parameter, selecting the reference parameter having the highest similarity by comparing the extracted parameter with the plurality of reference parameters,
Means for either outputting the encoding control signal or transmitting a reference control signal to the decoding side according to the value of the maximum similarity, and encoding the input image according to an instruction of the encoding control signal. And a means for transmitting the encoded data to the decoding side as encoded data, wherein the decoding device receives either the encoded data or the reference control signal from the encoding side for each input image, Means for recording and holding encoded data or selecting one from a plurality of previously recorded encoded data according to an instruction of the reference control signal and outputting it as reference data; either the encoded data or the reference data And a means for decoding and outputting as an output image. 3. A moving image coding / decoding method, wherein at the time of coding, a feature amount of an input image is extracted as a parameter, the extracted parameter is recorded and held by an instruction of a coding control signal, and the parameter is previously recorded. Outputting a plurality of recorded parameters as reference parameters, comparing the extracted parameters with the plurality of reference parameters to select the reference parameter having the highest degree of similarity,
Either output the encoded control signal or output a reference control signal to the decoding side according to the value of the maximum similarity, encode the input image according to an instruction of the encoded control signal, Output to the decoding side as encoded data, the difference between the extracted parameter and the selected reference parameter is output to the decoding side as a synthesis parameter, at the time of decoding, the encoded data for each of the input images or Either one of the reference control signals is input from the encoding side, the encoded data is recorded and held, or one is selected from the plurality of held encoded data according to the instruction of the reference control signal, and is selected as reference data. Output, decodes either the encoded data or the reference data and outputs as a decoded image, and outputs from the decoded image using the synthesis parameter. To synthesize an image output, code decoding method of the moving image, characterized in that. 4. A moving image coding / decoding device, wherein the coding device extracts a feature amount of an input image as a parameter, records the extracted parameter according to an instruction of a coding control signal, and stores the past parameter. A means for outputting the plurality of recorded parameters as a reference parameter, selecting the reference parameter having the highest similarity by comparing the extracted parameter with the plurality of reference parameters,
Depending on the value of the maximum similarity, means for performing either one of outputting the encoding control signal or transmitting a reference control signal to the decoding side, the input image by the instruction of the encoding control signal Means for transmitting to the decoding side as encoded data and encoded, and means for outputting the difference between the extracted parameter and the selected reference parameter to the decoding side as a synthesis parameter, the decoding device, Either the encoded data or the reference control signal is received from the encoding side for each input image, and the encoded data is recorded and held, or the plurality of held encoded data is instructed by the reference control signal. A means for selecting one and outputting it as reference data; a means for decoding either the encoded data or the reference data and outputting it as a decoded image; Utilizing growth parameters and means for combining outputs an output image from the decoded image code decoding apparatus of moving image, characterized in that.