JP3496378B2 - Digital image decoding device and digital image decoding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system such as a digital broadcasting system and a CATV system, and more particularly to a digital image decoding apparatus for the system.

[0002]

2. Description of the Related Art FIG. 16 shows, for example, "3-2-7 Error Tolerance", Nakajima et al., Journal of the Television Society, vol.49 No.4 pp4.
It is the conventional structural example regarding the error decoding of the image decoding apparatus shown by 63-464. In the figure, reference numeral 560 denotes an I picture (Intra-Picture, intra-coded image). The I-picture 560 is composed of, for example, 480 × 704 pixels, and is divided into 16 × 16 pixel macroblocks. An encoding method using predictive encoding between images such as MPEG (Moving Pictures Expert Group) is generally weak against an error. This is because predictive coding is done from previously decoded images. Therefore, once an error occurs, this error propagates in the time direction.

The simplest method for error concealment is to insert a block lost due to an error from a reference image for prediction as it is without considering motion. Further, in order to improve this performance, there is a method of performing motion compensation from a reference image and concealing using a motion vector. This is realized by the intra-concealment vector shown in FIG.
The intra-concealment vector is an I-picture (Int
ra picture) It is added to each macroblock of 560.
At this time, the added motion vector is the motion vector of the block located below the own block. The decoder stores the transmitted vector of each macroblock in units of horizontal row. If a block is lost due to an error, the vector of this block has already been transmitted and stored in one column, and this is used for concealment processing.

[0004]

The conventional digital decoding apparatus has been subjected to the concealment processing as described above. However, regarding the method of the concealment processing, only the use of the macroblock vector on one column is described. There was something that lacked concreteness. For example, there is no description about how to deal with a case where an error occurs even in a macroblock in a line below the macroblock in which an error has occurred, or when a motion vector to be applied indicates outside the effective area. Therefore, in the conventional digital decoding apparatus, for example, when an error occurs even in a macroblock in a line below the macroblock in which an error has occurred, if concealment processing is simply performed using the macroblock one column up, the block having little correlation will be obtained. Therefore, there is a problem that the propagation of error spreads visually and the image is disturbed.

The present invention has been made in order to solve the above problems, and relates to a digital image decoding apparatus and a digital image decoding method in which the practicality of concealment against an error is improved.

[0006]

According to a first aspect of the present invention, there is provided a digital image decoding apparatus which comprises an error detecting means for detecting a block error, a motion vector storing means for storing a plurality of motion vectors for each block, and a block It has a motion vector setting means for setting a motion vector and a motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, and when the error is detected by the error detecting means, the motion vector setting means, one also a plurality of motion vectors of neighboring blocks of the error block stored in the motion-out vector storage means
Based on the read motion vector
Calculated one or more motion vectors is used for setting the.

[0007] The digital image decoding apparatus according to the second invention, the block when an error is detected by said error detecting means for the uppermost block of the frame, the motion vector setting means in which the error is detected A zero vector is set as the motion vector of.

[0008]

[0009]

[0010]

[0011]

[0012]

[0013] The digital image decoding apparatus according to the third invention, the motion vector storage means according to the first invention, to select the motion vector of the temporally close frames to the frame of the plurality of vectors preferentially It is intended.

A digital image decoding device according to a fourth aspect of the present invention uses the motion vector storage means according to the first aspect of the present invention to preferentially select a motion vector of a frame temporally past the frame of the plurality of vectors. It is something that is supposed to be done.

The digital image decoding apparatus according to the fifth invention, when an error is detected by the pre-Symbol error detection means, said motion vector setting means from among a plurality of blocks stored in the motion vector storage unit A vector having the highest frequency is selected and set from among a plurality of motion vectors of blocks near the error block.

[0016]

A digital image decoding method according to a sixth aspect of the present invention is an error detecting step of detecting an error in a block, and when an error is detected in the error detecting step, a motion vector of the block in which the error is detected is used. A step of storing a zero vector in the motion vector storage means, and a motion vector of a block in the vicinity of the error block stored in the vector storage means is set in the vector setting means, and is further separated from a block adjacent to the error block. A step of not using the motion vector of the block, and a step of setting the motion vector of the block in the motion vector setting means and storing the motion vector of the block in the vector storage means when no error is detected in the error detecting step. And the motion vector And a motion compensation decoding step of performing motion compensation decoding using the motion vector set in the video setting unit.

A digital image decoding method according to a seventh aspect of the present invention comprises an error step of detecting a block error,
When an error is detected by the error detecting means in the uppermost block of the frame, a step of setting a zero vector in the motion vector setting means as a motion vector of the block in which the error is detected, It has a motion compensation decoding step of performing motion compensation decoding with the set motion vector.

[0019]

[0020]

A digital image decoding method according to an eighth aspect of the present invention is an error detecting step of detecting an error of a block, and one of the plurality of motion vectors is selected to block the selected motion vector. And a step of setting a motion vector of a block near the error block stored in the motion vector storage means to a motion vector setting means when an error is detected in the error storage step. And a motion compensation decoding step of performing motion compensation decoding using the motion vector set in the motion vector setting means.

A digital image decoding method according to a ninth aspect of the invention is an error detecting step of detecting a block error, a motion vector storing step of storing motion vectors of the plurality of blocks in a motion vector storing means, and the error detecting step. When an error is detected in the step, the vector having the highest frequency is selected and set from among the plurality of motion vectors of the blocks in the vicinity of the error block from the plurality of blocks stored in the motion vector storage means. It has a motion vector setting step and a motion compensation decoding step of performing motion compensation decoding with the motion vector set in the motion vector setting step.

A digital image decoding method according to a tenth aspect of the present invention comprises an error detection step of detecting an error in a block, a vector storage step of storing a plurality of motion vectors in each block in a motion vector storage means, and an error detection step. When an error is detected, one or more of the plurality of motion vectors of the blocks in the vicinity of the error block stored in the motion vector storage unit are read out and one or more of the plurality of motion vectors calculated based on the read out motion vector are read out. It has a motion vector setting step of setting a motion vector and a motion compensation decoding step of performing motion compensation decoding by the motion vector set in the motion vector setting means.

[0024]

DETAILED DESCRIPTION OF THE INVENTION

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 of the Invention Hereinafter, an embodiment of an invention of a decoding device according to the present invention will be described with reference to FIGS. 1 is a block diagram showing a decoding apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a motion vector storage memory according to an embodiment of the present invention, and FIG. 3 is a motion according to an embodiment of the present invention. It is a figure which shows the setting of a vector.

In FIG. 1, 100 is a decoding unit, 101 is an error detection unit that functions as an error detection unit, 102 is a motion vector storage unit that functions as a motion vector storage unit, 103 is a vector setting unit that functions as a vector setting unit, Reference numeral 104 is a frame memory, 105 is a motion compensation decoding unit that functions as motion compensation decoding means, 200 is encoded data, 201 is error analysis encoded data, 202 is an error flag, 203 is a decoded motion vector, and 20
4 is differential decoded data, 205 is a motion vector, 206 is a set motion vector, 207 and 208 are predicted image data, 209 is an adder, 210 is decoded image data,
Reference numeral 211 is an instruction signal.

In FIG. 2, reference numeral 300 denotes a motion vector storage location in each block, in which a motion vector is stored for each block. The same symbols as those in FIG. 1 indicate the same or corresponding contents. In FIG. 3, 310 is an image of one frame, 311 is an error block, 312 is a decoded normal block located immediately above the error block, 313 is a motion vector of the decoded normal block, and 314 is a motion set for the error block. Is a vector.

Next, the operation will be described with reference to FIGS. 1, 2 and 3. As shown in FIG. 1, the decoding unit 100 decodes the input encoded data 200. The coding method is a method in which one frame is divided into several blocks, each block is coded, and motion-compensated prediction is performed for each block between temporally neighboring frames (for example, H.261, M
PEG1 / 2 and vector quantization). In the embodiment of the present invention, the order of encoding and decoding is sequentially from the upper left to the right, and from the right end to the lower left end to the right.

The error detecting section 101 detects whether or not there is an error during decoding in the decoding section 100 based on the error analysis coded data 201. For example, the coded data for error analysis 201 is analyzed to detect an error while the input coded data 200 is being subjected to variable length decoding. Coded data for error analysis 201 is coded data 2
Of 00, only header data or encoded data 200 itself may be used, and the present invention is not limited as long as the data can detect an error required by the decoding device. When an error is detected, the error flag 202 is output to the decoding unit 100.

The decoding unit 100 outputs the motion compensation decoded vector 203 of the currently encoded block to the motion vector storage unit 102. The motion vector storage unit 102
This motion compensation decoded vector 203 is stored in a predetermined motion vector storage location 300. This motion vector storage unit 1
02 has a storage capacity for one horizontal block line.

When the decoding unit 100 receives the error flag 202, that is, when an error is detected during decoding, the decoding unit 100 instructs the vector setting unit 103 to set the motion vector for the error block. 211 is issued. The vector setting unit 103 sets a motion vector 205 (for example, a vector corresponding to the block 312 located directly above the error block 311 as shown in FIG. 3) stored in a predetermined location of the motion vector storage unit 102. This utilizes the tendency that a block is generally correlated with a block in the vicinity of the block in a moving image.

Block 312 and block 3 in FIG.
If the movement is different for 11 and 3 for the block of 311
It is not effective to apply the 12 vectors, but if the blocks 311 and 312 are some blocks of an image moving in the same direction, even if an error occurs in the block 311, the vectors of the 311 are 312 vectors. Applying is effective. The stronger the correlation with the neighboring block in the motion vector, the more effective it is.

The motion vector 20 is set in the vector setting unit 103.
After setting 5, the vector 0 (that is, no motion vector) is transferred from the decoding unit 100 to the motion vector storage unit 102 and stored therein. This is because the motion vector of the error block is unpredictable. With no errors,
Motion compensation decoded vector 203 decoded by the decoding unit 100
After being stored at a predetermined position in the motion vector storage unit 102, is output to the vector setting unit 103 as it is and output to the motion compensation decoding unit 105.

In the motion compensation decoding unit 105, according to the input motion vector 206, the predicted image data 207 is obtained from the frame memory 104 which stores prediction frames temporally close to each other.
Is output to the adder 209.

In the adder 209, the differential decoded data 204 output from the decoding unit 100 and the motion compensation decoding unit 105
The predicted image data 208 output by the above is added. The addition result is output to the display device as the decoded image data 210, and is output to the frame memory 104 when used for prediction of the next frame. Next error block 311
When the block immediately below (hereinafter referred to as block A) is an error block, the motion vector storage unit 102
In this case, the vector 0 stored in the position corresponding to the error block 311 is set in the motion vector setting unit 103. Block 3 immediately above the error block 311
12 is two blocks above block A. Therefore, since the block 312 further distant from the block adjacent to the block A generally has a lower correlation, the motion vector separated by two blocks is not used in this embodiment.

However, when the image moves in a wide portion of the image frame, there may be a case where the correlation between the motion vectors is strong even if they are separated by 2 blocks or more. Therefore, as another embodiment, 2 blocks or more. A vector based on the motion vector of the distant block may be applied to block A. In the first embodiment, the vector of the error block 311 itself is set to 0, and the 0 vector is applied to the block A immediately below the error block 311 is the block 3
This is because the influence of the error 11 is prevented from spreading to surrounding blocks. When looking at a decoded frame that is continuous in time, it seems that the error block sticks to the fixed position even if time elapses until the error is repaired by setting the vector to 0. If it is not 0, the image of the error block is updated according to the vector, and in some cases, the reproduced image may appear distorted.

As described above, the digital image decoding apparatus according to the invention described in the embodiments of the present invention includes error detecting means for detecting a block error, motion vector storage means for storing a motion vector of the block, It has a motion vector setting means for setting the motion vector of the block and a motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, and when an error is detected by the error detecting means, The motion vector setting means sets a motion vector of a block near the error block stored in the motion vector storage means, and the motion vector storage means stores a zero vector as a motion vector of a block in which the error is detected. Therefore, it is possible to reduce the error state and suppress the error propagation. The effect say.

In the embodiment of the invention described above, when the error block continues for several lines, only the first error block is set with the motion vector of the neighboring normal block in the motion vector setting unit 103, and the motion vector is stored. Part 10
Although 2 is set to 0, the present invention is not limited to this, and when an error block continues for several lines, up to an arbitrary line, a motion vector setting unit can be used as a vector to be applied to the error block in the vicinity. The motion vector of the normal block may be set, and 0 may be set in the motion vector storage unit 102 for the error block from the next line.

Second Embodiment of the Invention The embodiment of the present invention relates to the operation when an error is detected in the uppermost block of an image frame. The decoding device has the same configuration as that shown in FIG. FIG. 4 is a flowchart of the motion vector setting unit according to the embodiment of the present invention, and FIG. 5 is a diagram showing motion vector setting according to the embodiment of the present invention. 5, the same symbols as those in FIG. 3 indicate the same or the same contents.

Next, the operation will be described with reference to FIGS.
The motion vector setting unit 103 receives the error block 311 according to the error occurrence instruction signal 211 from the decoding unit 100.
A motion vector 205 of a block in the vicinity of, for example, a block immediately above is extracted from the motion vector storage unit 102 as a motion vector of an error block. Next is error block 3
It is determined whether 11 is the uppermost row of the image frame (step 401).

The error block 311 is the image frame 31.
If the block is located at the top block line of 0, the motion vector of the error block 311 is set to "0" as shown in FIG.
(Step 403). This is because there is no block that refers to the motion vector above the top row.
On the other hand, if it is determined in step 401 that the error block is not at the top of the image frame, the motion vector of the block immediately above is used as the motion vector of the error block (step 402).

The digital image decoding apparatus according to the invention described in the second embodiment of the present invention is an error detecting means for detecting a block error, a motion vector setting means for setting a block motion vector, and a motion vector setting. Motion compensation decoding means for performing motion compensation decoding with the motion vector set in the means, and when an error is detected by the error detecting means in the uppermost block of the frame, the motion vector setting means Since the zero vector is set as the motion vector of the block in which the error is detected, the data outside the region is not referred to, and the effect of not disturbing the image during error concealment is obtained.

Third Embodiment of the Invention FIG. 6 is a configuration diagram showing a motion vector storage memory according to the third embodiment of the present invention. The decoding device has the same configuration as that shown in FIG.
6, the same reference numerals as those in FIG. 2 indicate the same or equivalent contents. The operation of the decoding apparatus according to the embodiment of the present invention will be described with reference to FIGS. 3 and 6. The motion vector storage unit 102 according to the embodiment of the present invention can store a motion vector for one block line. Here, if the block is decoded normally, the motion vector of the block is stored in a storage location at a predetermined position, for example, 300a.

For the block in which the error has occurred, the motion vector of the block immediately above the error block (the normal decoding block 312 for the error block 311 as shown in FIG. 7 below) is set to the motion vector storage location 300.
After being read from n and output to the motion vector setting unit 103, "0" is written in the motion vector storage location 300n as the motion vector of the error block 311 itself.

This is because the motion vector of the error block is unpredictable due to an error, and is regarded as "no motion vector" and the motion vector is set to "0". By setting to "0", when the block directly below the error block becomes an error block further, the block immediately below reads "0" set to read the motion vector from the motion vector storage location 300n. . In this way, even if an error occurs in a block in the vertical direction of the image frame and the motion vector corresponding to the error block directly above must be used to perform motion-compensated prediction of its own error block, the error propagation is prevented. Control so that it does not spread more than necessary.

If the untrusted vector in the header information of the error block is used as it is as the motion vector of the error block, the erroneous vector is taken over and the subsequent block is decoded. By setting the motion vector of the error block to '0', the same image as the reference predicted image frame is extracted as the predicted image, so that there is no temporal image change and the error propagation does not spread unnecessarily. There is a visible effect. Further, it has an effect of suppressing the error propagation even when decoding the blocks after the error block.

In the above example, when a block on the same frame as a neighboring block and a block immediately above is used as a motion vector for a block in which an error has occurred, it is as shown in FIG. The motion vector of the error block 3 1 in which the error has occurred is set to the motion vector 313 of the normal processing block 312 located immediately above the error block and the motion vector 3 of the error block.
However, using the motion vector of the block on the left of the error block, that is, the block decoded immediately before, or the block near the error block (however, the block that has already been decoded because it is estimated not to be an error block) However, this does not limit the present invention.

Further, in the embodiment of the invention described above, the motion vector for one block line is stored, but it is not particularly limited to one block line, and the capacity of the memory can be changed according to the contents of the error concealment. You can change it,
It does not limit the invention.

As described above, the digital image decoding apparatus according to the invention described in the third embodiment of the present invention includes an error detecting means for detecting a block error and a motion vector storing means for storing a motion vector of the block. , A motion vector setting means for setting the motion vector of the block,
A motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, and when an error is detected by the error detection means, the motion vector setting means stores the motion vector storage means in the motion vector storage means. The motion vector of the block adjacent to the error block is set, and the motion vector storage means stores a zero vector as the motion vector of the block in which the error is detected. Therefore, the error state is reduced and the error is propagated. There is an effect that can suppress.

Fourth Embodiment of the Invention FIG. 7 is a diagram showing setting of motion vectors according to Embodiment 4 of the present invention.
In FIG. 7, the same numbers as those in FIG. 3 indicate the same or equivalent contents. FIG. 8 is a flow showing the operation of the motion vector setting unit according to the fourth embodiment of the present invention. The decoding device has the same configuration as that shown in FIG.

Next, the operation will be described with reference to FIGS. 7 and 8. In the motion vector setting unit 103, the motion vector storage unit 10 stores a motion vector 205 corresponding to a block near the error block (directly above or just to the left of FIG. 7) in response to an error occurrence instruction signal 211 from the decoding unit 100.
Take out from 2. When the motion vector 205 is applied to the error block 311, it is determined whether the motion vector 205 goes out of the image frame 310 (step 801).

When the motion vector 205 is applied to the error block 311, and if the motion vector 205 is out of the image frame 310, the motion vector setting unit 103 sets the motion vector to "0" (step 803). This is because the applied motion vector cannot predict, and the reason for setting the motion vector to "0" is to prevent the image from changing temporally compared with the error block to be decoded and the predicted image. .

The motion vector 205 is set to the error block 31.
When applied to No. 1, if the image frame 310 does not run off, the motion vector setting unit 102 sets this motion vector (step 802).

In FIG. 7, an example in which the vector 323 to which the motion vector 313 of the block 312 immediately above the error block 311 is applied points to the prediction invalid area, and the motion vector 31 of the block 316 just to the left of the error block 311 is shown.
The vector 327 to which 7 is applied represents an example of pointing to the prediction invalid region.

The digital image decoding apparatus according to the embodiment of the present invention comprises an error detecting means for detecting a block error, a motion vector storing means for storing a block motion vector, and a motion vector for setting a block motion vector. It has a setting means and a motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, and when an error is detected by the error detecting means, the error is detected. When the motion vector of the block near the error block is set as the motion vector of the error block, when pointing to the invalid area outside the frame, the vector setting unit reads the error block of the error block read from the motion vector storage unit. Set after the motion vectors of neighboring blocks are shortened Since, the effect of preventing to perform the prediction is out of range data.

In particular, since the zero vector is set by the vector setting means as a shortening process, there is an effect that it is possible to reliably and easily prevent the prediction with the data outside the range.

Fifth Embodiment of the Invention FIG. 9 is a diagram showing setting of motion vectors according to the fifth embodiment of the invention. In FIG. 9, the same numbers as those in FIGS. 3 and 7 indicate the same or equivalent contents. FIG. 10 is a flow showing the operation of the decoding device according to the fifth embodiment of the invention. The decoding device has the same configuration as that shown in FIG.

Next, the operation will be described with reference to FIGS. 9 and 10. In the motion vector setting unit 103, the motion vector storage unit 1 stores a motion vector 205 corresponding to a block near the error block (directly above or just to the left of FIG. 9) in response to an error occurrence instruction signal 211 from the decoding unit 100.
Take out from 02.

First, when the motion vector 205 is applied to the error block 311, it is judged whether or not the motion vector 205 is out of the image frame 310 (step 1001). If the motion vector 205 is applied to the error block 311, and the motion vector 205 extends beyond the image frame 310, the motion vector setting unit 103 sets the motion vector by shortening the vector to the frame boundary, that is, the prediction region effective limit (step 1003). This is because the applied motion vector cannot predict, so the reason why the motion vector is shortened and set is that by matching the motion reproduced by the error block to be decoded to the motion of the block near the error block, This is to minimize the change in the image spatially as compared with the block.

If it is determined in step 1001 that the motion vector 205 is applied to the error block 311 and does not extend from the image frame 310, the motion vector of the block immediately above is used as the motion vector of the error block.

In the fourth embodiment of the invention, there is no temporal change in the image, whereas in the fifth embodiment of the invention, the change in the image is spatially minimized as described above. This is because of the reason.

As described above, according to the invention described in the embodiments of the present invention, since the digital image decoding apparatus shortens the vector setting means to a vector up to the effective area limit of the frame as a shortening process, the error block It is possible to perform compensation by using a motion vector of a block near the block and a vector close to the block, and it is possible to perform error concealment with better reproducibility in terms of time or space.

In FIG. 9, an example of the vector 324 in which the motion vector 313 of the block 312 immediately above the error block 311 is shortened to the predictable limit and applied, and the motion vector 3 of the block 316 just to the left of the error block 311 is shown.
Vector 32 that is applied by reducing 17 to the predictable limit
8 shows an example.

Sixth Embodiment of the Invention FIG. 11 is a diagram showing setting of motion vectors according to the sixth embodiment of the invention.
11, FIG. 3, FIG. 9, FIG. 12, FIG.
The same numbers as 3 indicate the same or equivalent contents. The configuration of the decoding device is the same as that of FIG.

Next, the operation will be described with reference to FIG. When an error is detected during the decoding of the frame 310 currently being decoded, not only the decoding process according to the above-described embodiment of the present invention is performed on the current error block 311, but also the next error that is not affected by the current error is detected. All blocks 315 up to immediately before the decoding unit are also regarded as error blocks, and the processing of the embodiment of the present invention is performed.

If the block next to the current error block 311 can be decoded independently of the current error block 311, only the current error block 311 is subjected to error processing, and the subsequent blocks 315 and subsequent blocks are subjected to normal decoding processing. be able to. However, when the next block is decoded based on the parameters and data of the current error block 311, the current error is taken over, so that even if there is no abnormality in operation thereafter, the result will be an error block.

Therefore, a circuit for identifying whether the block next to the current error block 311 can be decoded independently of the current error block 311 is inserted, and if it is independent, the subsequent blocks 315 and subsequent blocks 315 are decoded normally. You may be allowed to do. However, in general, adjacent blocks have a strong correlation with each other. For example, the correlation between blocks is used to improve the coding efficiency by, for example, calculating the difference between DC components and motion vectors between the blocks and coding the difference signal. Often.

Therefore, in the case of decoding the general coded data as described above, the blocks 315 after the error is detected are all blocks 315 up to immediately before the next decoding unit which is not affected by the current error. There is a method of forcibly treating it as a uniform error block, and in that case, it is not necessary to add a special circuit such as the identification circuit. However, when adjacent blocks can be independently decoded, the blocks that can be normally decoded are also processed as uniform error blocks. Therefore, it is identified whether or not the adjacent block to be decoded next can be decoded independently of the current error block, and if independent decoding is possible, it is possible to perform normal decoding after the adjacent block until the next new error is detected. To This operation is performed for each block up to immediately before the next decoding unit (for example, slice unit or picture unit) which is not affected by the current error. By thus limiting the influence of the error to the block in which the error has occurred, not only the propagation of the error is suppressed, but also error concealment with higher reproducibility can be performed.

In the digital image decoding apparatus according to the invention described in the embodiments of the present invention, the error detecting means for detecting an error in a block and the block and an adjacent block which is adjacent to this block and is to be decoded next are independent. And a motion vector setting means for setting the motion vector of the block, and a motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, When an error is detected by the error detecting means, and when the identifying block determines that the adjacent block that is adjacent to the error block and is to be decoded next cannot be decoded independently of the error block, the motion Since the vector setting means sets a motion vector also as an error block for the adjacent block, the error block is set. If the click after block might take over error is an effect of suppressing the propagation of the errors.

Seventh Embodiment of the Invention FIG. 12 is a diagram showing setting of motion vectors according to Embodiment 7 of the present invention. 12, the same numbers as those in FIGS. 3, 7, 9 and 13 indicate the same or the same contents. The decoding device has the same configuration as that shown in FIG.

In the figure, 302, 303, 304, 31
Reference numerals 0, 330, and 331 are image frames. The motion vectors 342 and 352 are motion vectors of the normal block 312 corresponding to the frame 302, and the motion vectors 343 and 353 are motion vectors of the normal block 312 corresponding to the frame 331. One frame may consist of two fields, and when a motion vector is obtained from each field, two motion vectors may be calculated from one frame in this way.

Next, the operation will be described with reference to FIG. When the currently decoding frame 310 decodes the temporally past frame 302 and the temporally future frame 331 as prediction images, the motion compensation corresponding to the frame 302 used for prediction is performed in block 312 during normal decoding. Two vectors of the prediction frames of the vectors 342 and 352 and the motion compensation vectors 343 and 353 corresponding to each field of the frame 331 are used.
When an error occurs in the frame 310, one of the motion compensation vectors 342, 343, 352, 353 of a block (directly above in FIG. 12) near the error block 311 is used as a motion compensation vector of the error block 311. Apply the compensation vector.

This is because the reproducibility of error blocks is not always improved even if all motion compensation vectors of blocks near the error block are used, and a memory for storing all vectors is required. . The vector storage memory for error blocks can be reduced by applying only a part of the number of vectors, and the reproducibility of error blocks is generally the same as when using all motion compensation vectors. I can say it.

For example, vectors 342, 343, 35.
When motion compensation is performed using all 2, 353, the vectors 342 and 343 are vectors of the same frame,
Similarly, since the vectors 352 and 353 are vectors of the same frame, each vector 3 in the same frame is
Images predicted from 42, 343 or vectors 352, 353 are almost always the same or similar.

Further, in the case of performing motion estimation, since the prediction is performed based on the image predicted from the above four vectors, if the four images are not the same or similar images, the original coded data has the coding efficiency. Is bad and the prediction efficiency is poor. For example, the prediction based on the image predicted from the four vectors is the four predicted images (or 34
2 and 343 if the were those using the arithmetic mean image is 352 and the two-frame predicted image 353 pairs) pairs, irrelevant predicted image, and therefore if Re image Oh dissimilar any one There is no point in taking the arithmetic mean.

Therefore, assuming that the data is coded in consideration of the coding efficiency and the prediction efficiency, for example, the images predicted from the above four vectors are all the same or similar images. It can be said that

For the above reason, even if motion compensation is performed using the motion compensation vectors of the number of blocks in the vicinity of the error block, the error block is reproduced whether compared with the case where all the motion compensation vectors are used. Explain that there is not much difference in sex.

Although the motion compensation vector corresponding to each field is described in the embodiment of the present invention,
It may be a motion compensation vector corresponding to each subblock obtained by dividing each block. It is also clear that there may be multiple vectors that differ in time, and that the multiple motion compensation vectors used for any given block are not the only ones corresponding to the field, and the motion corresponding to the field Obviously, a motion compensation vector other than the compensation vector may be used and does not limit the present invention.

The digital image decoding apparatus according to the invention described in the embodiments of the present invention comprises an error detecting means for detecting an error in a block and a motion vector selected from a plurality of motion vectors. A motion vector storage means for storing each block, a motion vector setting means for setting a motion vector of the block, and a motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, When an error is detected by the error detecting means, the motion vector setting means sets the motion vector of the block in the vicinity of the error block stored in the motion vector storage means. For more reproducible and efficient error concealment There is an effect that it is possible.

Eighth Embodiment of the Invention FIG. 13 is a diagram showing setting of motion vectors according to the eighth embodiment and the ninth embodiment of the present invention. 13, the same numbers as those in FIGS. 3, 7, and 9 indicate the same or the same contents. The decoding device has the same configuration as that shown in FIG.

Next, the operation will be described with reference to FIG. When the currently decoding frame 310 decodes the temporally past frame 302 and the temporally future frame 331 as prediction images, the motion compensation corresponding to the frame 302 used for prediction is performed in block 312 during normal decoding. Either the vector 342 and / or the motion compensation vector 343 corresponding to the frame 331 is used.

If an error occurs in frame 310,
As the motion compensation vector of the error block 311, the motion compensation vector 343 of the frame 331 temporally close to the frame 310 of the motion compensation vectors 342 and 343 of the blocks (directly above in FIG. 13) near the error block 311 is applied.

This is because the use of a plurality of motion compensation vectors does not necessarily improve the reproducibility of error blocks, and requires a memory for storing a plurality of vectors. Vector storage memory for error blocks can be minimized by applying only one vector. Further, the reason why the motion compensation vector 343 of the frame 331 that is temporally close to the frame 310 is applied is that reproducibility is generally better when a predicted image is extracted than a temporally closer predicted frame when the subject is moving. Because it is expensive.

As described above, in the digital image decoding apparatus according to the invention described in the embodiment of the present invention, the motion vector storage means stores the motion vector of the frame temporally close to the frame among the plurality of vectors. Since the selection is performed with priority, when an error occurs, the error block can be subjected to an error concealment process with better reproducibility and efficiency.

Ninth Embodiment of the Invention Next, the operation of the decoding apparatus according to Embodiment 9 of the present invention will be described with reference to FIG. When the currently decoding frame 310 decodes the temporally past frame 302 and the temporally future frame 331 as prediction images, the motion compensation corresponding to the frame 302 used for prediction is performed in block 312 during normal decoding. Either the vector 342 and / or the motion compensation vector 343 corresponding to the frame 331 is used.

If an error occurs in frame 310,
As the motion compensation vector of the error block 311, the motion compensation vector 342 of the frame 302 decoded before the frame 310 is applied among the motion compensation vectors 342 and 343 of the blocks (directly above in FIG. 13) near the error block 311. .

This is because the use of a plurality of motion compensation vectors does not always improve the reproducibility of the error block, and requires a memory for storing a plurality of vectors. Vector storage memory for error blocks can be minimized by applying one vector. However, depending on the purpose, select all or some of the multiple motion vectors so that error concealment with a high degree of reproducibility can be performed regardless of memory capacity, and then select a motion vector based on the selected motion vector. It can also be applied to error blocks. That is, it does not mean that any one of the expressions "selection" is selected in the narrow sense, but it means that all or some (including one) vectors are selected as described above. The meaning of “selection” is the same as in the other embodiments.

The reason why the motion compensation vector 342 of the frame 302 decoded before the frame 310 is applied is always "past" or "future" by applying the motion compensation vector from the past frame. It is not necessary to store the parameter, and the eighth embodiment of the invention has a characteristic that the nearer in time can be either “past” or “future” and has high reproducibility. In the ninth embodiment, by limiting the applied vector to the “past” vector, it is possible to reduce the vector storage memory for the error block as compared with the eighth embodiment of the invention.

As described above, in the digital image decoding apparatus according to the invention described in the embodiment of the present invention, the motion vector storage means stores the motion vector of a frame temporally past the frame among the plurality of vectors. Since there is no need to consider future image frames, it is possible to perform reproducible and efficient error concealment processing on error blocks with less hardware, since it has been selected with priority. There is an effect that can be.

Tenth Embodiment of the Invention FIG. 14 is a diagram showing setting of motion vectors according to Embodiment 10 of the present invention. 14, FIG. 3, FIG. 7, FIG. 9 and FIG.
The same numbers as and indicate the same or equivalent contents. The decoding device has the same configuration as that shown in FIG.

In each of the above-described embodiments, an example in which a block which is on the one block line of the same frame as the neighboring block and is immediately above is used as the motion vector of the block in which an error has occurred is described. As shown in 3, the motion vector 31 of the normal processing block 312 located immediately above the error block in which the error has occurred
3 was applied.

However, not only the motion vector 313 of the block 312, but also the motion vector 317 of the block 316 to the left of the error block, that is, the motion vector 317 of the block just decoded or the true vector of the left block 318 of the error block, the true vector of the error block. Upper right block 3
A motion vector based on a motion vector of a block near the error block, such as 20 motion vectors 321, may be used, and the present invention is not limited thereto.

The “based vector” referred to here is a motion vector to which any one or a plurality of motion vectors is applied, even if it is an arithmetic mean of the plurality of motion vectors or the plurality of motion vectors. It may be the vector with the highest frequency and does not limit the invention. In other words, the purpose is to obtain a vector by a method of calculating a vector that is as close as possible to the motion vector originally held by the error block.

This utilizes the tendency that a certain block is generally correlated with a block in the vicinity of the block in a moving image. It goes without saying that the stronger the correlation between the motion vector and the neighboring blocks, the higher the reproducibility of the motion vector.

The digital image decoding apparatus according to the invention described in the embodiments of the present invention includes an error detecting means for detecting a block error, a motion vector storing means for storing motion vectors of the plurality of blocks, and Motion vector setting means for setting the motion vector of the block,
A motion compensation decoding unit that performs motion compensation decoding by the motion vector set in the motion vector setting unit, and when the error detection unit detects an error, the motion vector setting unit stores the motion vector in the motion vector storage unit. Since a motion vector suitable for the error block is selected from a plurality of stored blocks and set, when an error occurs, efficient error concealment processing with better reproducibility can be performed on the error block. Has the effect.

Eleventh Embodiment of the Invention FIG. 15 is a block diagram showing a decoding device according to Embodiment 11 of the present invention. 15, the same reference numerals as those in FIG. 1 indicate the same or equivalent contents. Next, the operation of the decoding device will be described with reference to FIG. If an error is detected during the decoding of the frame 310 currently being decoded, the current error block 31
When the block next to 1 can be decoded independently of the current error block 311, only the current error block 311 can be subjected to error processing, and the blocks 315 after the next error block can be subjected to normal decoding processing. However, when the next block is decoded on the basis of the parameters and data of the current error block 311, the current error is taken over, so that even if the operation is not abnormal after that, the result is an error block.

Therefore, the error determination unit 220 is required to determine whether the block next to the current error block 311 can be decoded independently of the current error block 311. The error determination unit 220 inputs the encoded data 200 of the next block and the next block when the block currently being decoded is found to be in error by the error instruction signal 202 sent from the error detection unit 101. Analyze the characteristics after the block.

As a result of the analysis, if it is possible to decode independently of the current error block, the subsequent block 315 and subsequent blocks can perform normal decoding processing. Error determination signal 221 indicating that the decoding can be performed independently of
Is sent. In the decoding unit 100, if the signal indicates "independent code enabled", only the current error block is subjected to error processing (error block vector setting). For example, if the block immediately after the error block is INTRA MB (MB coded by intra-frame prediction), the block immediately after the error block can be decoded independently of the error block.

On the other hand, as a result of the analysis, when the current error block cannot be decoded independently, "independent decoding is impossible"
Signal is sent from the error determination unit 220 to the decoding unit 100, and the decoding unit 100 not only performs the decoding process on the current error block 311 as in the above-described embodiment, but also does not affect the current error. All the blocks 315 up to immediately before the decoding unit are regarded as error blocks and the error processing of the above embodiment is performed on the motion vector setting unit 103. For example, when a block immediately after the error block generates a vector based on the motion vector of the error block, the independent decoding is impossible.

In the eleventh embodiment, “all the blocks 315 up to immediately before the next decoding unit, which are not affected by the current error, are regarded as error blocks and the motion vector setting unit 103 is subjected to the above-mentioned operation. However, it is not always necessary to consider all blocks 315 as error blocks. That is, as described in the sixth embodiment, it is determined whether or not the adjacent block to be decoded next can be decoded independently of the current error block, and if independent decoding is impossible, the adjacent block is regarded as an error block and the processing is performed. If independent decoding is possible, the adjacent blocks and the subsequent blocks are normally decoded until a new error is detected. This operation is performed for each block up to immediately before the next decoding unit (for example, slice unit or picture unit) which is not affected by the current error. In other words, if it is checked whether each block can be decoded independently of the immediately preceding error block, the influence of the error will be kept as much as possible as the block that caused the error rather than being regarded as a uniform error block after the error block. Therefore, not only the error propagation can be suppressed but also the error concealment with higher reproducibility can be performed.

When "independent decoding is impossible", the motion vector is set to "0" for all blocks 315 up to immediately before the next decoding unit which is not affected by the current error. There is a case where a vector is applied based on a block vector (case 2), and one of the vectors is set for each block. The advantage of the case 1 is that the error does not spread to the place other than the place where the error occurs until the error block is refreshed (for example, the INTRA frame comes after several frames). However, the error block (group) can be seen at a glance because the image is always the same until the refresh.

The advantage of case 2 is that an image close to the original image of the error block can be reproduced. However,
If there is a slight error and the period until refreshing is long, the error accumulates and the influence of the error spreads to the area near the error block. Since Case 1 and Case 2 have their respective merits and demerits, it is necessary to decide which to select according to the conditions.

In the above embodiment, the coded data 200 of the next block and subsequent blocks are input. In this case, however, the error judgment section 220 needs to decode the coded data. The data necessary for the analysis may be input from the decoding unit 100.

If the operation of the error determining section is performed by the decoding section, the error determining section may be included in the decoding section as a circuit configuration, and the present invention is limited by the circuit configuration. is not.

In the digital image decoding apparatus according to the invention described in the embodiments of the present invention, the error detecting means for detecting an error in the block and the block and the adjacent block which is adjacent to this block and is decoded next are independent. And a motion vector setting means for setting the motion vector of the block, and a motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, When an error is detected by the error detecting means, and when the identifying block determines that the adjacent block that is adjacent to the error block and is to be decoded next cannot be decoded independently of the error block, the motion Since the vector setting means sets a motion vector also as an error block for the adjacent block, the error block is set. If the click after block might take over error is an effect of suppressing the propagation of the errors.

[0105]

According to the first aspect of the present invention, there is provided a digital image decoding device, which comprises an error detecting means for detecting a block error,
Motion vector storage means for storing a plurality of motion vectors for each block, motion vector setting means for setting the motion vector of the block, motion compensation decoding means for performing motion compensation decoding by the motion vector set in the motion vector setting means, has, if an error is detected by the error detection means, said motion vector setting means, one or more reading a plurality of motion vectors of neighboring blocks of the error block stored in the motion-out vector storage means This
One or more calculated based on the read motion vector
Because setting a plurality of motion vectors, together with an effect of suppressing the propagation of the errors as well as reducing the error status, with less hardware, error
Reproducible and efficient error correction for blocks
It has the effect that
To do.

[0106] The digital image decoding apparatus according to the second invention, the block when an error is detected by said error detecting means for the uppermost block of the frame, the motion vector setting means in which the error is detected Since the zero vector is set as the motion vector of, the effect of not disturbing the image at the time of error concealment is made without referring to the data of the part outside the area.

[0107]

[0108]

[0109]

[0110]

[0111]

In the digital image decoding apparatus according to the third aspect of the invention, the motion vector storage means according to the first aspect of the invention preferentially selects the motion vector of the frame temporally close to the frame among the plurality of vectors. Therefore, when an error occurs, there is an effect that the error block can be subjected to an efficient error concealment process with better reproducibility.

A digital image decoding apparatus according to a fourth aspect of the present invention uses the motion vector storage means according to the first aspect of the present invention to preferentially select a motion vector of a frame that is temporally past the frame of the plurality of vectors. Since we did not need to consider future image frames,
It is possible to perform efficient error concealment processing with better reproducibility on error blocks with less hardware.

[0114] The digital image decoding apparatus according to the fifth invention, when an error is detected by the pre-Symbol error detection means, said motion vector setting means from among a plurality of blocks stored in the motion vector storage unit Since the vector with the highest frequency is selected and set from the multiple motion vectors of blocks near the error block, when an error occurs, the error concealment with better reproducibility and efficiency for the error block It is possible to perform the ment processing.

[0115]

[0116] A digital image decoding method according to a sixth aspect of the present invention is an error detecting step of detecting an error in a block, and when an error is detected in the error detecting step, the motion vector of the block in which the error is detected is used. A step of storing a zero vector in the motion vector storage means, and a motion vector of a block in the vicinity of the error block stored in the vector storage means is set in the vector setting means, and is further separated from a block adjacent to the error block. A step of not using the motion vector of the block, and a step of setting the motion vector of the block in the motion vector setting means and storing the motion vector of the block in the vector storage means when no error is detected in the error detecting step. And the motion vector Since it has a motion compensation decoding step of performing motion compensation decoding by the motion vector set in the rule setting means, it is possible to reduce the error state and suppress the error propagation.

A digital image decoding method according to a seventh aspect of the present invention comprises an error step of detecting a block error,
When an error is detected by the error detecting means in the uppermost block of the frame, a step of setting a zero vector in the motion vector setting means as a motion vector of the block in which the error is detected, Since there is a motion compensation decoding step for performing motion compensation decoding with the set motion vector, there is an effect that the image of the portion outside the area is not referred and the image is not disturbed during error concealment.

[0118]

[0119]

A digital image decoding method according to an eighth aspect of the present invention is an error detecting step of detecting an error in a block, and selecting one motion vector from the plurality of motion vectors to block the selected motion vector. And a step of setting a motion vector of a block near the error block stored in the motion vector storage means to a motion vector setting means when an error is detected in the error storage step. And a motion compensation decoding step for performing motion compensation decoding using the motion vector set in the motion vector setting means, so that more error-promoting error concealment with less hardware and more reproducibility is possible. The effect that processing can be performed is produced.

A digital image decoding method according to a ninth aspect of the invention is an error detecting step of detecting a block error, a motion vector storing step of storing motion vectors of the plurality of blocks in a motion vector storing means, and the error detecting step. When an error is detected in the step, the vector having the highest frequency is selected and set from among the plurality of motion vectors of the blocks in the vicinity of the error block from the plurality of blocks stored in the motion vector storage means. Since it has a motion vector setting step and a motion compensation decoding step of performing motion compensation decoding with the motion vector set in the motion vector setting step, when an error occurs, it is more reproducible and efficient with respect to the error block. The effect that can perform error concealment processing Play.

A digital image decoding method according to a tenth aspect of the present invention comprises an error detecting step of detecting an error in a block, a vector storing step of storing a plurality of motion vectors for each block in a motion vector storing means, and an error detecting step. When an error is detected, one or more of the plurality of motion vectors of the blocks in the vicinity of the error block stored in the motion vector storage unit are read out and one or more of the plurality of motion vectors calculated based on the read out motion vector are read out. Since it has a motion vector setting step of setting a motion vector and a motion compensation decoding step of performing motion compensation decoding by the motion vector set in the motion vector setting means, it is possible to perform more reproducibility with respect to an error block with less hardware. Good and efficient error concealment The effect that processing can be performed is produced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a decoding device according to an embodiment of the invention.

FIG. 2 is a diagram showing a motion vector storage memory according to the first embodiment of the invention.

FIG. 3 is a diagram showing setting of motion vectors according to the first embodiment of the invention.

FIG. 4 is a flowchart of a motion vector setting unit according to the second embodiment of the invention.

FIG. 5 is a diagram showing setting of motion vectors according to the second embodiment of the invention.

FIG. 6 is a diagram showing a motion vector storage memory according to a third embodiment of the invention.

FIG. 7 is a diagram showing setting of motion vectors according to the fourth embodiment of the invention.

FIG. 8 is a flowchart of a motion vector setting unit according to the fourth embodiment of the invention.

FIG. 9 is a diagram showing setting of motion vectors according to the fifth embodiment of the invention.

FIG. 10 is a flowchart of a motion vector setting unit according to the fifth embodiment of the invention.

FIG. 11 is a diagram showing setting of motion vectors according to the sixth embodiment of the invention.

FIG. 12 is a diagram showing setting of motion vectors according to the seventh embodiment of the invention.

FIG. 13 is a diagram showing setting of motion vectors according to the eighth embodiment of the invention and the ninth embodiment of the invention.

FIG. 14 is a diagram showing setting of motion vectors according to the tenth embodiment of the invention.

FIG. 15 is a block diagram showing a decoding device according to an eleventh embodiment of the invention.

FIG. 16 is a diagram showing setting of a conventional motion vector.

[Explanation of symbols]

100 decoding unit, 101 error detection unit, 102 motion vector storage unit, 103 vector setting unit, 104 frame memory, 105 motion compensation decoding unit, 200 coded data, 201 error analysis coded data, 202
Error flag, 203 motion vector, 204 differential decoded data, 205 motion vector, 206 set motion vector, 207 predicted image data, 208 predicted image data, 209 adder, 210 decoded image data, 2
11 instruction signal, 220 error determination unit, 221 error determination signal, 300 motion vector storage location, 302 predicted image frame, 303 predicted image frame, 304
Predicted image frame, 310 Decoded image frame, 311
Error block, 312 normal decoding block (immediately above the error block), 313 motion vector of normal decoding block, motion vector applied to 314 error block, block after 315 error block, 316
Decoding normal block (right side of the error block) 317
Decoded normal block motion vector, 318 Decoded normal block (right side of error block), 319 Decoded normal block motion vector, 320 Decoded normal block (directly above right block of error block), 321 Decoded normal block motion vector, A motion vector outside the area to be applied to the H.323 error block, a motion vector shortened to the area limit applied to the 324 error block,
A motion vector outside the area to be applied to the 327 error block, a motion vector shortened to the area limit applied to the 328 error block, 330 predicted image frame, 331 predicted image frame, 342 predicted motion vector, 343 predicted motion vector, 352 motion vector predictor, 353 motion vector predictor, 560 decoded frames.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-253288 (JP, A) JP-A-7-79441 (JP, A) JP-A-5-153574 (JP, A) JP-A-63- 50284 (JP, A) Yasuyuki Nakajima, Toshinori Otaka, Katsumi Tahara, Special Feature MPEG "3-2-7 Error Tolerance", Journal of the Television Society of Japan "Image Information Engineering and Broadcasting Technology", Japan Television Society, 1995 4 20th, Vol. 49, No. 4, pp. 464-464 (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N ^7/ 24-7/68

Claims (10)

(57) [Claims] 1. A digital image decoding apparatus for dividing an image in a frame into a plurality of blocks and decoding encoded data encoded for each block using a plurality of motion vectors for each block, Error detecting means for detecting an error of, a motion vector storing means for storing the plurality of motion vectors for each block, a motion vector setting means for setting a motion vector of the block, and a motion set in the motion vector setting means. And a motion compensation decoding means for performing motion compensation decoding by a vector, when an error is detected by the error detection means,
The motion vector setting means reads one or a plurality of motion vectors of a block near the error block stored in the motion vector storage means and calculates one or a plurality of motion vectors based on the read motion vector. A digital image decoding device characterized in that 2. When an error is detected by the error detecting means in the uppermost block of the frame, the motion vector setting means sets a zero vector as a motion vector of the block in which the error is detected. The digital image decoding device according to claim 1, wherein Wherein said motion vector storage means, the digital image decoding apparatus according to claim 1, wherein the selecting motion vectors of temporally close frames to the frame of the plurality of vectors preferentially. Wherein said motion vector storage means, the digital image decoding according to claim 1, wherein the selecting than the frame temporally motion vectors of past frames of the plurality of vectors preferentially apparatus. If an error is detected by 5. Before Symbol error detecting means, the motion vector setting means a plurality of blocks in the vicinity of the error block from among a plurality of blocks stored in the motion vector storage unit 2. The digital image decoding device according to claim 1 , wherein a vector having the highest frequency is selected and set from among the motion vectors. 6. A digital image decoding method for dividing an image in a frame into a plurality of blocks and decoding encoded data encoded for each block, an error detecting step of detecting an error of the block, When an error is detected in the error detection step, a step of storing a zero vector in the motion vector storage means as a motion vector of the block in which the error is detected, and the vicinity of the error block stored in the vector storage means Setting the motion vector of the block of the vector to the vector setting means, not using the motion vector of the block further distant from the block adjacent to the error block, and if no error is detected in the error detection step, Motion vector motion vector setting means And a motion compensation decoding step of performing motion compensation decoding with the motion vector set in the motion vector setting means, and a motion compensation decoding step of storing the motion vector of the block in the vector storage means. 7. When an error is detected by the error detecting means in the uppermost block of the frame, a zero vector is set in the motion vector setting means as a motion vector of the block in which the error is detected. 7. The digital image decoding method according to claim 6, further comprising a motion compensation decoding step of performing motion compensation decoding using the motion vector set in the motion vector setting means. 8. A digital image decoding method for dividing an image in a frame into a plurality of blocks and decoding encoded data encoded in each block using a plurality of motion vectors in each block, Error detection step of detecting the error of, the vector storage step of storing any one of the plurality of motion vectors to store the selected motion vector for each block, the error in the error detection step When detected, the step of setting the motion vector of the block near the error block stored in the motion vector storage means in the motion vector setting means, and the motion compensation decoding by the motion vector set in the motion vector setting means. Image decoding with motion-compensated decoding step Law. 9. A digital image decoding method for dividing an image in a frame into a plurality of blocks and decoding coded data coded for each block, an error detecting step of detecting an error in the block, A motion vector storing step of storing motion vectors of a plurality of blocks in a motion vector storing means; and when an error is detected in the error detecting step, the error is selected from the plurality of blocks stored in the motion vector storing means. A motion vector setting step of selecting and setting a vector with the highest frequency among a plurality of motion vectors of blocks in the vicinity of the block, and a motion compensation decoding step of performing motion compensation decoding using the motion vector set in the motion vector setting step, A digital image decoding method having a. 10. A digital image decoding method for dividing an image in a frame into a plurality of blocks and decoding encoded data encoded for each block using a plurality of motion vectors for each block, An error detection step of detecting an error, a vector storage step of storing the plurality of motion vectors in each block in a motion vector storage means, and when an error is detected in the error detection step, in the motion vector storage means A motion vector setting step of setting one or more motion vectors calculated based on the read one or more motion vectors of the stored blocks near the error block and the motion vector setting; Motion-compensated decoding by the motion vector set in the method The digital image decoding method characterized by having a motion compensation decoding step of performing.