JP2003274413A - Error handling apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply excellent error compensation with a less memory quantity and a small processing load to a picture in which an error is caused. <P>SOLUTION: An image signal decoding section 100 receiving a bit stream decodes encoded image data. An in-block average pixel value calculation section 103 calculates an average value of an in-block pixel decoded by the image signal decoding section 100. An error processing section 102 applies error compensation for decoding the image signal by the image signal decoding section 100 and when a macro block is interpolated, the error compensation is realized by using a reference image on the basis of an average value of pixels of a block first decoded in a picture calculated by the in-block average pixel value calculation section 103. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an error processing device in image decoding processing, and more particularly to an error processing device in MPEG decoding processing.

[0002]

2. Description of the Related Art Conventionally, MPEG is known as a standard image coding technique for mainly compressing moving image data.
The MPEG-4 video bitstream will be described below as an example. The image data in MPEG-4 is
Sequence, VOP (Video Object Plane),
It has a hierarchical structure of five layers of VP (video packet), MB (macro block), and block. And MP
In the bit stream of EG-4, a start code is added to the beginning of each of the above sequence, VOP, and VP, which is a structural unit, and if an error occurs during decoding, skip to the next start code. The decryption can be restored immediately.

Here, for the skipped portion, the macro block that has been omitted due to an error is replaced with the macro block at the same spatial position of the previous VOP, that is, it is replaced with an image similar to the original image to make it inconspicuous. The method is common. Also, the first VO that does not have a reference image
Since P has no substitute VOP, it is configured to use an image initialized with an appropriate value instead of the reference image.

Further, in Japanese Laid-Open Patent Publication No. 9-154135 (error processing device), a macro block is generated by generating a mirror image of a macro block located immediately above the macro block which is missing due to an error. Is used to interpolate and configure the error compensation to be replaced by the image in the frame.

[0005]

[Problems to be Solved by the Invention]
The method of replacing the macroblock of P with the same spatial position requires a memory for storing the image of the previous VOP as a reference image. Further, in the first picture, the scene-changed picture, the INTRA picture, etc., the temporal correlation with the previous picture is small, so that the previous VOP
Even if it is replaced with the macro block at the same position, there is a large difference from the surrounding image, and there are cases where appropriate error compensation cannot be performed.

Further, in the method disclosed in Japanese Patent Application Laid-Open No. 9-154135, since the interpolation by the mirror image is performed in the VOP, the memory for storing the reference image is not necessary, but conversely, the mirror is used. There is a problem that a memory for generating an image is required and the processing load increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an error processing apparatus capable of performing good error compensation for a picture in which an error has occurred, with a small memory amount and a processing load.

[0008]

An error processing apparatus of the present invention receives an image signal decoding means for receiving a bit stream and decoding encoded image data, and performs decoding by the image signal decoding means. In-block average pixel value calculating means for calculating the average value of the in-block pixels, and error processing means for performing error compensation when the image signal is decoded by the image signal decoding means. In the case of interpolation, error processing means for performing error compensation using a reference image based on the average value of the pixels of the block which is first decoded in the picture calculated by the in-block average pixel value calculation means, The configuration including is adopted.

According to this structure, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
Since the reference image is not a fixed image but adaptively changes depending on the average value of the pixels of the first decoded block, the error-compensated macroblock can be obtained as a visually and frequency-interpolated image. .

The error processing device of the present invention receives an image signal decoding means for receiving a bit stream and decoding encoded image data, and an image signal decoding means for decoding the bit stream by the image signal decoding means. , A DC coefficient extracting means for extracting a DC coefficient of a block decoded in a picture, and an error processing means for performing an error compensation when the image signal is decoded by the image signal decoding means, In the case of interpolation, an error processing unit for performing error compensation using a reference image based on the DC coefficient in the block first decoded in the picture extracted by the DC coefficient extraction unit is provided. take.

According to this configuration, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
The processing load is smaller than that of calculating the average value of the pixels in the block. Further, the reference image adaptively changes depending on the DC coefficient of the first decoded block, so that the error-compensated macroblock can be obtained as a visually and frequency-interpolated image.

The error processing device of the present invention calculates the average value of macroblock pixels from the average pixel value of each block in the macroblock calculated by the block average pixel value calculation means. The error processing means is a macroblock which is first decoded in the picture calculated by the intra-macroblock average pixel value calculation means when interpolating a macroblock. The average pixel value of is used as a reference image.

According to this structure, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
Since the reference image adaptively changes not only in the first decoded block but also in the average value of the pixels of the macroblock, it is possible to perform error compensation at a value closer to the value of the entire screen. Is obtained as an interpolated image that is good both visually and in terms of frequency.

According to the error processing apparatus of the present invention, the DC in each block in the picture extracted by the DC coefficient extracting means is
An intra-macro-block average DC coefficient calculating means for calculating a macro-block average value of coefficients, wherein the error processing means is calculated by the intra-macro-block average DC coefficient calculating means when interpolating a certain macro block. In the first decoded macroblock in the selected picture
A configuration is used in which the coefficient average value is used as a reference image.

According to this configuration, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
The processing load is smaller than that of calculating the average value of pixels in the macroblock, and the reference image adaptively changes according to the average value of the DC coefficient of the first decoded macroblock. The error compensation can be performed, and the macroblock subjected to the error compensation can be obtained as an interpolated image that is good in terms of both visual and frequency.

The error processing apparatus of the present invention calculates the average value of the slice from the average pixel value of each macroblock in the slice calculated by the intra-block average pixel value calculation means and the macroblock average pixel value calculation means. In-slice average pixel value calculating means, wherein the error processing means, when interpolating a certain macroblock, the macroblock in the first slice of the picture calculated by the in-slice average pixel value calculating means The average pixel value of is used as a reference image.

According to this configuration, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
Since the reference image is not a fixed image but adaptively changes according to the average value of the pixels in the first slice of the picture, error compensation is performed with a value closer to the value of the entire screen than the average value of the macroblock pixels. Thus, the macroblock subjected to the error compensation can be obtained as an interpolated image with higher accuracy both visually and in terms of frequency.

The error processing apparatus of the present invention calculates the average DC coefficient in slices for calculating the average of the DC coefficients of each macroblock extracted by the DC coefficient extraction means and the intra-macroblock average DC coefficient calculation means in slices. The error processing means refers to the average of the DC coefficients of the blocks in the first slice of the picture calculated by the in-slice average DC coefficient calculation means when interpolating a certain macroblock. The configuration used as an image is adopted.

According to this structure, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
The processing load is smaller than that of calculating the average value of the pixels in the slice. Further, since the reference image adaptively changes according to the average value of the DC coefficient of each block in the slice, error compensation can be performed with a value closer to the value of the entire screen, and the macroblock that has performed the error compensation can be visually recognized. It is possible to obtain an interpolated image with higher accuracy both in terms of frequency and frequency.

In the error processing device of the present invention, when the first macroblock or slice of a picture cannot be decoded normally, the error processing means uses the data of the next macroblock or slice that can be decoded normally. Adopt a configuration for error compensation.

According to this configuration, interpolation can be performed even for the head macroblock or slice of a picture. Further, since it is not necessary to store the previous picture in the memory, no special frame memory is needed. Further, the error-compensated macroblock can be obtained as an interpolated image that is good both visually and in terms of frequency.

The error processing method according to the present invention includes an image signal decoding step of receiving a bitstream and decoding encoded image data, and a pixel in block decoded in the image signal decoding step. An intra-block average pixel value calculation step of calculating an average value, and an error processing step of performing error compensation when decoding the image signal in the image signal decoding step, wherein when interpolating a macroblock, And an error processing step of performing error compensation using a reference image based on the average value of pixels of the block which is first decoded in the picture calculated in the intra-block average pixel value calculation step. .

According to this method, since it is not necessary to store the image of the previous picture used for error compensation in the memory, no special frame memory is required. Also,
Since the reference image is not a fixed image but adaptively changes depending on the average value of the pixels of the first decoded block, the error-compensated macroblock can be obtained as a visually and frequency-interpolated image. .

The program of the present invention is a program for causing a computer to execute the method described in the above invention, and the computer executes the operation of any one of the claims by making the program readable by a machine. be able to.

The image communication apparatus of the present invention has a configuration including the error processing apparatus described in any of the above inventions.

The mobile communication system of the present invention has a configuration including the image communication device described in the above invention.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION In the essence of the present invention, when interpolating a macroblock, an error is caused by using the pixel average value or DC coefficient of the first decoded block in a picture as a reference image. For the picture
This is to enable good error compensation with a small memory amount and a processing load.

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

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an error processing apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, the error processing apparatus according to the first embodiment includes an image signal decoding unit 100, a decoded image storage unit 101, an error processing unit 102, and an intra-block average pixel value calculation unit 103. Has been done.

The image signal decoding unit 100 receives the bit stream sent from the outside and decodes the encoded image data. The decoded image storage unit 101 stores the image data decoded by the image signal decoding unit 100. In the error processing unit 102, error compensation is performed and interpolation is performed on macroblocks in which data is missing.
The in-block average pixel value calculation unit 103 calculates an average value as a reference image from the pixels in the decoded block.

Next, the operation of the error processing apparatus according to the first embodiment having the above configuration will be described with reference to FIG.

In FIG. 1, the image signal decoding unit 100 performs a decoding process on a bit stream sent from the outside. Here, in the image signal decoding unit 100, when the image is normally decoded without any error, the decoded image is stored in the decoded image storage unit 1 for each macroblock.
01 and stored. Further, the decoded image data is output to the intra-block average pixel value calculation unit 103. The intra-block average pixel value calculation unit 103 calculates the average value of the pixels of the decoded block as a reference image, and outputs the reference image to the error processing unit 102.

On the other hand, in the image signal decoding unit 100, when decoding becomes impossible in a certain macroblock of the bitstream, the leading macroblock number of the video packet to which the macroblock in which the error has occurred belongs to the error processing. Sent to the section 102.

The error processing unit 102 extracts a substitute macroblock from the reference image in the already decoded decoded image. That is, the image block at the same position is extracted from the reference image of the picture in which the error has occurred, interpolation is performed in the video packet in which the error has occurred, and the image block is stored in the decoded image storage unit 101. The content of this error compensation is
The content is the same as that described in the above-mentioned conventional technique. In the image signal decoding unit 100, the operation is continued until the next decodable start code video packet, and then the normal decoding process is resumed.

Here, in the error processing unit 102, when there is no picture before the first picture in the bit sequence, that is, when there is no previous picture in time and there is no picture to refer to, The above interpolation cannot be performed. Therefore, the error processing unit 10
In 2, the video pixel in which an error has occurred is interpolated using the average value of the pixels of the first decoded block calculated by the intra-block average pixel value calculation unit 103 as the reference image, and the decoded image storage unit It is stored in 101.

As described above, according to the first embodiment, since the value of the previous picture is not used when performing error compensation on a certain picture, it is possible to reduce the memory for storing the image. Also, since the reference image used for error compensation is not a fixed image but adaptively changes according to the average value (picture) of the pixels of the first decoded block, it is possible to interpolate with the same value as the original image. It becomes possible to perform more appropriate error compensation.

(Embodiment 2) FIG. 2 is a block diagram showing the configuration of an error processing apparatus according to Embodiment 2 of the present invention. In FIG. 2, the error processing apparatus according to the second embodiment includes an image signal decoding unit 100 and a decoded image storage unit 10.
1, an error processing unit 102, and a DC (Direct Current) coefficient extraction unit 201.

That is, as shown in FIG. 2, in the error processing device according to the second embodiment, instead of the intra-block average pixel value calculation unit 103 shown in FIG.
1 is provided. Here, the description will focus on the part related to the second embodiment.

In the DC coefficient extraction unit 201, when the image signal decoding unit 100 decodes the bit stream, the DC
The coefficients are extracted. The DC coefficient is used as a reference image by the error processing unit 102.

Next, the operation of the error processing apparatus according to the second embodiment having the above configuration will be described with reference to FIG.

In FIG. 2, when the image signal decoding unit 100 decodes a bitstream, the DC coefficient extraction unit 2
At 01, the DC coefficient is extracted. The DC coefficient is a DCT transform (Discrete Cosine Transform)
It is the DC component of the area converted by, and indicates the average of the pixel values in the block.

The bit stream stores the difference from the DC coefficient of the adjacent block. At the time of decoding, the original DC coefficient can be decoded by adding the DC coefficient difference extracted from the bit stream and the DC coefficient of the already decoded adjacent block.

In the error processing unit 102, when the bitstream cannot be decoded in a certain macroblock, the reference image area is initialized using the DC coefficient extracted in advance by the DC coefficient extraction unit 201, Interpolation of errored video packets is performed.

As described above, according to the second embodiment, as in the first embodiment, the value of the previous picture is not used when performing error compensation on a certain picture, so that a memory for storing an image is provided. Can be reduced. In addition, since the DC coefficient of the block is used, the processing load is smaller than that in the first embodiment in which the average value of the pixels in the block is calculated. Further, since the reference image adaptively changes according to the DC coefficient of the first decoded block, an excellent effect such as obtaining an error-compensated macroblock as a visually or frequency-interpolated image that is good is obtained. Can be expected.

(Embodiment 3) FIG. 3 is a block diagram showing the configuration of an error processing apparatus according to Embodiment 3 of the present invention. In FIG. 3, the error processing apparatus according to the third embodiment includes an image signal decoding unit 100 and a decoded image storage unit 10.
1, the error processing unit 102, the intra-block average pixel value calculation unit 103, and the macro-block average pixel value calculation unit 30.
It is composed of 1 and 1.

That is, as shown in FIG. 3, in the error processing apparatus according to the third embodiment, in the configuration shown in the first embodiment (FIG. 1), the intra-macroblock average pixel value calculation unit 301 It is provided between the average pixel value calculation unit 103 and the error processing unit 102. Here, the description will focus on the part related to the third embodiment.

Intra-macroblock average pixel value calculation unit 301
Then, from the average pixel value of each block in the macroblock calculated by the in-block average pixel value calculation unit 103, the average value of the pixels of the macroblock is calculated as a reference image.

Next, the operation of the error processing apparatus according to the third embodiment, which can be expected to have the above-mentioned configuration, will be described with reference to FIG. In FIG. 3, when a bitstream becomes undecodable in a certain macroblock, the intra-block average pixel value calculation unit 103 calculates the average value of the pixels of the first decoded block, and In the intra-macroblock average pixel value calculation unit 301, the average value of the pixels of the macroblock that is first decoded is calculated.

In the error processing unit 102, the reference image area is initialized using the value calculated by the intra-macroblock average pixel value calculation unit 301, and the video packet in which the error has occurred is interpolated.

As described above, according to the third embodiment, as in the first and second embodiments, the value of the previous picture is not used when performing error compensation on a certain picture, so that the image can be stored. The memory can be reduced. In addition, since the reference image adaptively changes not only in the first decoded block but also in the average value of the pixels of the macroblock, it is possible to perform error compensation with a value closer to the value of the entire screen, and visually. An excellent effect that an interpolated image excellent in terms of frequency and frequency can be obtained can be expected.

(Embodiment 4) FIG. 4 is a block diagram showing the configuration of an error processing apparatus according to Embodiment 4 of the present invention. In FIG. 4, the error processing apparatus according to the fourth embodiment includes an image signal decoding unit 100 and a decoded image storage unit 10.
1, an error processing unit 102, a DC coefficient extraction unit 201, and an intra-macroblock average DC coefficient calculation unit 401.

That is, as shown in FIG. 4, in the error processing apparatus according to the fourth embodiment, in the configuration shown in the second embodiment (FIG. 2), the intra-macroblock DC coefficient calculating section 401 has the DC coefficient Extraction unit 201 and error processing unit 1
It is provided between 02 and. Here, the description will focus on the part related to the fourth embodiment.

Intra-macroblock average DC coefficient calculator 40
In 1, the average value of the DC coefficient of each block extracted by the DC coefficient extraction unit 201 in the macro block is calculated as a reference image.

Next, the operation of the error processing apparatus according to the fourth embodiment, which can be expected to have the above-mentioned configuration, will be described with reference to FIG. In FIG. 4, when the image signal decoding unit 100 decodes a bitstream, the DC coefficient extraction unit 2
At 01, the DC coefficient is extracted. Then, after the DC coefficient of each block in the macroblock is extracted by the DC coefficient extraction unit 201, the average DC coefficient value in the macroblock is calculated by the intra-macroblock average DC coefficient calculation unit 401 as a reference image.

In the error processing unit 102, when the bitstream cannot be decoded in a certain macroblock, the reference image area is initialized using the value calculated by the intra-macroblock average DC coefficient calculation unit 401, Interpolation of errored video packets is performed.

As described above, according to the fourth embodiment, as in the first to third embodiments, when the error compensation is performed on a certain picture, the value of the previous picture is not used, so that the image is stored. The memory can be reduced. In addition, since the DC coefficient of each block in the macroblock is used,
The processing load is smaller than that of calculating the average value of all pixels in the macroblock. In addition, since the reference image adaptively changes according to the average value of the DC coefficient of the macroblock decoded first, it is possible to perform error compensation with a value closer to the value of the entire screen, and visually and in terms of frequency. An excellent effect that a good interpolation image can be obtained can be expected.

(Embodiment 5) FIG. 5 is a block diagram showing the configuration of an error processing apparatus according to Embodiment 5 of the present invention. In FIG. 5, the error processing apparatus according to the fifth embodiment includes an image signal decoding unit 100 and a decoded image storage unit 10.
1, an error processing unit 102, an in-block average pixel value calculation unit 103, and an in-macroblock average pixel value calculation unit 301
And an intra-slice average pixel value calculation unit 501.

That is, as shown in FIG. 5, in the error processing device according to the fifth embodiment, in the configuration shown in the third embodiment (FIG. 3), the intra-slice average pixel value calculation unit 50 is used.
1 is provided between the intra-macroblock average pixel value calculation unit 301 and the error processing unit 102. Here, the description will focus on the part related to the fifth embodiment.

The intra-slice average pixel value calculation unit 501 calculates the average of slices from the average pixel value of each macroblock in the slice calculated by the intra-block average pixel value calculation unit 103 and the macroblock average pixel value calculation unit 301. The value is calculated. A slice is a set of macroblocks from the left end to the right end of one picture, and one slice is composed of 16 lines.

Next, the operation of the error processing apparatus according to the fifth embodiment, which can be expected to have the above configuration, will be described with reference to FIG. In FIG. 5, when decoding is not possible in a macroblock having a bitstream, the intra-block average pixel value calculation unit 103 calculates the average value of the pixels of the first decoded block, and The intra-macroblock average pixel value calculation unit 301 calculates the average value of the pixels of the macroblock that is first decoded.

Then, the intra-slice average pixel value calculation unit 50
1, the average pixel value of the slice is calculated from the average pixel value of each macroblock in the first decoded slice calculated by the intra-block average pixel value calculation unit 103 and the macroblock average pixel value calculation unit 301. It is calculated as a reference image.

In the error processing unit 102, the reference image area is initialized using the value calculated by the intra-slice average pixel value calculation unit 501, and the video packet in which the error has occurred is interpolated.

As described above, according to the fifth embodiment, as in the first to fourth embodiments, when the error compensation is performed on a certain picture, the value of the previous picture is not used, so that the image is stored. The memory can be reduced. In addition, since the reference image is not a fixed image but changes adaptively according to the average value of the pixels in the first slice of the picture,
It is possible to perform error compensation with a value that is closer to the value of the entire screen than the average value of the pixels of the macro block, and it is expected to have an excellent effect that a highly accurate interpolated image can be obtained visually and in frequency. .

(Sixth Embodiment) FIG. 6 is a block diagram showing the structure of an error processing apparatus according to the sixth embodiment of the present invention. In FIG. 6, the error processing apparatus according to the sixth embodiment includes an image signal decoding unit 100 and a decoded image storage unit 10.
1, an error processing unit 102, a DC coefficient extraction unit 201,
The macro block average DC coefficient calculation unit 401 and the slice average DC coefficient calculation unit 601 are included.

That is, as shown in FIG. 6, in the error processing apparatus according to the sixth embodiment, the intra-slice average DC coefficient calculation unit 6 has the configuration shown in the fourth embodiment (FIG. 4).
01 is provided between the intra-macroblock average DC coefficient calculation unit 401 and the error processing unit 102. Here, the description will focus on the part related to the sixth embodiment.

The intra-slice average DC coefficient calculating section 601 includes a DC coefficient extracting section 201 and an intra-macroblock average DC coefficient.
An average value of DC coefficients of each macroblock extracted by the coefficient calculation unit 401 in a slice is calculated as a reference image.

Next, the operation of the error processing apparatus according to the fourth embodiment, which can be expected to have the above configuration, will be described with reference to FIG. In FIG. 6, when the image signal decoding unit 100 decodes a bitstream, the DC coefficient extraction unit 2
At 01, the DC coefficient is extracted. DC coefficient extraction unit 201
After the DC coefficient of each block in the slice is extracted at D, the intra-macroblock average DC coefficient calculation unit 401
The average value of the C coefficient is calculated as the reference image.

Then, the intra-slice average DC coefficient calculation unit 6
In 01, the average value of the DC coefficient of each macroblock extracted by the DC coefficient extraction unit 201 and the intra-macroblock average DC coefficient calculation unit 401 in a slice is calculated as a reference image.

In the error processing unit 102, when the bitstream cannot be decoded in a certain macroblock, the reference image area is initialized using the value calculated by the intra-slice average DC coefficient calculation unit 601. The video packets in error are interpolated.

As described above, according to the sixth embodiment, as in the first to fifth embodiments, the value of the previous picture is not used when performing error compensation on a certain picture, so that the image can be stored. The memory can be reduced. In addition, since the DC coefficient of each block in the slice is used, the processing load is smaller than that in calculating the average value of the pixels in the slice. Further, since the reference image adaptively changes according to the average value of the DC coefficient of each block in the slice, error compensation can be performed with a value closer to the value of the entire screen, and it is more visually and frequency-wise. An excellent effect such as obtaining a highly accurate interpolated image can be expected.

Here, in the first to sixth embodiments, when the first macroblock or slice of a picture cannot be decoded normally, the error processing unit 102 decodes the next macroblock or slice that has been decoded normally. Error compensation is performed using the data of. Therefore, it becomes possible to perform interpolation even on the head macroblock or slice of a certain picture.

A program that causes a computer to execute the error processing method implemented by the error processing device according to the present invention can be generated, and the program can be read by a machine, so that any one of the operations can be performed. Can be performed by a computer.

Since the error processing device according to the present invention can be incorporated as an image communication device, it is possible to realize a mobile communication system equipped with such an image communication device.

[0074]

As described above, according to the present invention,
With respect to a picture in which an error has occurred, good error compensation can be performed with a small memory amount and a processing load.

[Brief description of drawings]

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

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

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

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

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

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

[Explanation of symbols]

100 image signal decoding unit 101 Decoded image storage unit 102 error processing unit 103 block average pixel value calculation unit 201 DC coefficient extraction unit 301 Average pixel value calculation unit in macro block 401 Average DC Coefficient Calculation Unit in Macroblock 501 slice average pixel value calculation unit 601 Intra-Slice Average DC Coefficient Calculation Unit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5C059 MA00 RF09 TA76 TB06 TB08                       TC02 TC04 TC22 TD03 UA05                 5J064 AA02 AA04 BB04 BB08 BC01                       BC21 BC27

Claims (11)

[Claims] 1. A block which receives a bit stream and which decodes encoded image data, and a block which calculates an average value of pixels in a block decoded by the image signal decoding unit. An internal average pixel value calculation means and an error processing means for performing error compensation when the image signal is decoded by the image signal decoding means, and when the macroblock is interpolated, the block average pixel value calculation is performed. An error processing device that performs error compensation using a reference image based on an average value of pixels of a block that is first decoded in a picture calculated by the device. 2. An image signal decoding means for receiving a bitstream and decoding encoded image data, and a decoding within a picture when the bitstream is decoded by the image signal decoding means. A DC coefficient extracting means for extracting the DC coefficient of the block, and an error processing means for performing error compensation when the image signal is decoded by the image signal decoding means. An error processing device comprising: an error processing device that performs error compensation using a reference image based on a DC coefficient in a block first decoded in a picture extracted by the DC coefficient extraction device. . 3. An in-macroblock average pixel value calculating means for calculating an average value of pixels in the macroblock from an average pixel value of each block in the macroblock calculated by the in-block average pixel value calculating means. Then, the error processing means refers to the average pixel value in the macroblock decoded first in the picture calculated by the in-macroblock average pixel value calculation means when interpolating a certain macroblock. The error processing device according to claim 1, wherein the error processing device is used as an image. 4. An intra-macroblock average DC coefficient calculating means for calculating a macroblock average value of DC coefficients in each block in a picture extracted by the DC coefficient extracting means,
The error processing means, when interpolating a certain macroblock, the DC coefficient average in the macroblock decoded first in the picture calculated by the intra-macroblock average DC coefficient calculating means. The error processing device according to claim 2, wherein the value is used as a reference image. 5. An in-slice average pixel value for calculating an average value of a slice from average pixel values of respective macroblocks in a slice calculated by the in-block average pixel value calculating means and the in-macroblock average pixel value calculating means The error processing means refers to the average pixel value of the macroblock in the first slice of the picture calculated by the intra-slice average pixel value calculation means when interpolating a certain macroblock. The error processing device according to claim 3, wherein the error processing device is used as an image. 6. An intra-slice average DC coefficient calculation means for calculating an average of DC coefficients of each macro block extracted by the DC coefficient extraction means and macro block average DC coefficient calculation means in a slice, When the certain macroblock is interpolated, the error processing means uses the average of the DC coefficients of the blocks in the first slice of the picture calculated by the intra-slice average DC coefficient calculation means as a reference image. The error processing device according to claim 4. 7. The error processing means, when the first macroblock or slice of a picture cannot be decoded normally, performs error compensation using the data of the macroblock or slice that has been successfully decoded next. The error processing device according to any one of claims 1 to 6, which is characterized. 8. A block for receiving a bitstream and decoding encoded image data, and a block for calculating an average value of pixels in the block decoded in the image signal decoding step. An inner average pixel value calculation step and an error processing step of performing error compensation when decoding an image signal in the image signal decoding step, wherein the intra-block average pixel value calculation is performed when a certain macroblock is interpolated. An error processing step of performing error compensation using a reference image based on an average value of pixels of a block which is first decoded in the picture calculated in the step. 9. A program for causing a computer to execute the method according to claim 8. 10. An image communication device comprising the error processing device according to claim 1. Description: 11. A mobile communication system comprising the image communication device according to claim 10.