JPH06113283A - Motion compensation coder - Google Patents

Abstract

PURPOSE:To obtain the motion compensation coder in which a code quantity of a motion vector is reduced by using two kinds of motion vectors and a limit range or the limit range and a threshold level. CONSTITUTION:A television signal inputted from an input terminal 11 is divided into small blocks by a block divider 8a and a motion vector detector 9a obtains a motion vector. Furthermore, a block divider 8b divides the signal into large blocks and a motion vector detector 9b obtains the motion vector. An output decide device 10 sets a limit range in response to the motion vector of each of the large blocks with respect to the motion vector obtained by the motion vector detector 9b and when the motion vector of the small block in each of the large block is in existence in the limit range, the motion vector of the large block is used to apply motion compensation of the small block.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion compensation coding apparatus for performing motion compensation and coding on a video signal.

[0002]

2. Description of the Related Art Generally, a motion compensation coding apparatus compresses a video signal by obtaining a motion vector between frames (or fields) and performing motion compensation. Of these, the one most often used is inter-frame prediction for obtaining a motion vector between frames, and a macro block or DCT block (hereinafter, simply referred to as a block) of the current frame for which motion compensation is performed. The interpolation image created temporally forward or backward or forward and backward is searched for a position having the smallest difference in the vicinity of the block of the current frame, and the difference is searched for and encoded. In addition, the motion vector obtained as a result is
It is represented by two components in the vertical direction, and predictive coding is performed with the motion vector of the immediately preceding block as the predicted value, and variable length coding is performed on the horizontal direction prediction error and the vertical direction prediction error. Regarding the coding method of the coding apparatus using such interframe prediction, for example, "International Standard of Multimedia Coding": Maruzen Co., Ltd., pages 114 and 128.
Pages 129 to 129.

[0003]

However, in the conventional method, when a motion vector detection error occurs, motion compensation is performed using an incorrect motion vector, and the motion vector of the immediately preceding block is Since the prediction error of is variable length coded, the problem that the error propagates when decoding the motion vector, and since the code was assigned to the motion vector of the same value or a similar value, There is a problem that the coding efficiency is reduced.

The present invention solves the drawbacks of the conventional coding apparatus as described above, and prevents motion compensation from being performed by using a wrong motion vector, or prevents error propagation of the motion vector, as compared with the related art. Another object of the present invention is to provide a motion compensation coding apparatus that improves the coding efficiency of a motion vector.

[0005]

In order to achieve this object, a motion compensation coding apparatus of the present invention divides an input television signal into a plurality of small blocks, and calculates a motion vector in each of the small blocks. Block vector detection means,
Large block vector detecting means for dividing an input television signal into large blocks each having a size of the plurality of small blocks and obtaining a motion vector in each of the large blocks, and each motion vector obtained in each of the large blocks On the other hand, when a limited range setting means for setting a limited range according to the motion vector of each large block, and each motion vector of the small blocks in each large block are present within the limited range, Using a motion vector of each of the large blocks, a motion compensation switching means for performing motion compensation and coding on the small blocks existing within the limited range is provided.

Threshold setting means for setting a threshold value for the number of motion vectors of the small blocks in each of the large blocks existing within the limited range, and movement of each of the large blocks when the motion vector exceeds the threshold value. Motion compensation means for compensation,
Alternatively, a motion vector encoding unit that encodes a motion vector of a small block existing within the limited range by calculating a difference value with the motion vector of each large block, or performs motion compensation by each large block, The motion compensation means performs motion compensation for each small block outside the limited range by using the difference vector from the motion vector of each large block.

[0007]

With this configuration, the encoding apparatus of the present invention uses the motion vectors of the blocks of two different sizes and the limited range or the limited range and the threshold value to make an error when a motion vector detection error occurs. This function prevents motion compensation from being performed by using such a motion vector, prevents error propagation at the time of decoding the motion vector, or improves the coding efficiency of the motion vector.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is a subtractor for obtaining a difference between input signals, and 2 is an orthogonal transformer for performing orthogonal transformation on the input signals.
3 is a quantizer for quantizing the input signal, 4a and 4b
Is an encoder for encoding the input signal, 5 is an inverse quantizer for inverse quantizing the input signal, 6 is an inverse orthogonal transformer for inverse orthogonal transforming the input signal, and 7 is the sum of the input signals Adders, 8a and 8b are block dividers that divide the input signal into blocks, 9a and 9b are motion vector detectors that obtain motion vectors from the input signals, and 10 is an output determiner that determines and outputs the output from the input signal, 11 Is an input terminal for inputting a television signal.

With respect to the encoding apparatus having the above-mentioned components, the relation and operation of the components will be described below.

The first frame (or first field, hereinafter referred to as frame 1) of the television signal input from the input terminal 11 is a subtractor 1 and a motion vector detector 9
a and the motion vector detector 9b. Since the frame 1 is not subjected to motion compensation, it is transmitted to the orthogonal transformer 2 without being processed by the subtractor 1. Then frame 1
Is orthogonally transformed by the orthogonal transformer 2, quantized by the quantizer 3, and transmitted to the encoder 4 a and the inverse quantizer 5. The frame 1 transmitted to the encoder 4a is the encoded signal 12
1 which is output as and is input to the inverse quantizer 5
Is inverse-quantized by the inverse quantizer 5, inverse-orthogonal transformed by the inverse orthogonal transformer 6, passes through the adder 7, and is input to the block divider 8a and the block divider 8b. As with the subtracter 1, the adder 7 does not process the frame 1.

The frame 1 transmitted from the adder 7 is divided into small blocks by the block divider 8a and divided into large blocks having a size of a plurality of small blocks by the block divider 8b. The small block divided by the block divider 8a is transmitted to the motion vector detector 9a and the output determiner 10, and the large block divided by the block divider 8b is
It is transmitted to the motion vector detector 9b. The motion vector detector 9a detects a motion vector between the input small block and the second frame (hereinafter referred to as frame 2) which is the next frame input from the input terminal 11, and the motion vector detector 9b Motion vectors are detected between the input large block and the frame 2, and the motion vectors detected by the respective motion vector detectors are transmitted to the output determiner 10.

The output determiner 10 sets a limited range corresponding to each large vector with respect to the motion vector (hereinafter referred to as a large vector) input from the motion vector detector 9b, and the small blocks in each large block are set. Of the motion vector (hereinafter, referred to as a small vector) is output as a motion vector 14 of each small block when the motion vector 14 is within the limited range, and a large vector is not within the limited range. . The output motion vector 14 is encoded by the encoder 4b and output as an encoded signal 15. Further, the output determiner 10 outputs the motion vector, and at the same time, outputs the small block video signal 13 input from the block divider 8a. The outputted small block video signal 13 is transmitted to the subtracter 1 and the adder 7.

Subsequent to the frame 2 and subsequent frames, the subtracter 1
Then, the difference from the transmitted small block video signal 13 is obtained and transmitted to the orthogonal transformer 2. After that, the adder 7
The processing up to is the same as the case of frame 1. Adder 7
Then, the sum of the signal transmitted from the inverse orthogonal transformer 6 and the small block transmitted from 19 is obtained and transmitted to the block divider 8a and the block divider 8b. The subsequent processing is the same as in the case of frame 1.

As described above, in this embodiment, the input television signal is divided into a plurality of small blocks by the block divider 8a, and the motion vector detector 9a obtains the motion vector of each small block. And a large block vector detector for dividing the input television signal into large blocks having a block size corresponding to the plurality of small blocks by a block divider 8b, and obtaining a motion vector of each large block by a block divider 9b. Means, limiting range setting means for setting a limiting range corresponding to the motion vector of each large block with respect to each motion vector obtained by the output determining device 10 in each large block, If each motion vector of a small block is within the limited range, the motion vector of each large block is used to By providing a motion compensation coding means for performing motion compensation and coding on a small block existing in the area, when a large number of similar motion vectors appear in the large block, these are treated as one vector and the difference value between the motion vectors is set. To improve the motion vector coding efficiency.

Next, a second embodiment of the present invention will be described with reference to the drawings. In FIG. 2, 1 is a subtractor, 2
Is an orthogonal transformer, 3 is a quantizer, 4a and 4b are encoders, 5 is an inverse quantizer, 6 is an inverse orthogonal transformer, 7 is an adder,
8a and 8b are block dividers, 9a and 9b are motion vector detectors, 10a is an output determiner, and 11 is an input terminal.

With respect to the encoding device having the above components, the connection and operation of the components will be described.

Frame 1 input from input terminal 11
Are processed in the same manner as in the first embodiment up to the block divider 8a and the block divider 8b. In the present embodiment, the small blocks divided by the block divider 8a and the large blocks detected by the block divider 8b are transmitted to the output determiner 10a, the motion vector detector 9a and the motion vector detector 9b. The motion vector detector 9a and the motion vector detector 9b detect motion vectors between the frame 1 and the frame 2 as in the first embodiment, and input them to the output determiner 10a.

In the output determiner 10a, a limited range corresponding to each large vector is set for the large vector of each large block as in the case of the first embodiment. Further, in this embodiment, the limited range exists. A threshold value is set for the number of small vectors of small blocks to be set. When the number of small vectors exceeds the threshold value, the output determiner 10a outputs the video signal 16 and the large vector 17 of the large block input from the block divider 8b. The input small block video signal 16 and small vector 17 are output. The output video signal of the large block or the small block 16 is processed in the same manner as in the first embodiment, and the output motion vector 17 is encoded by the encoder 4b.
The encoded signal 18 is output. Subsequent processing is the first
This is the same as in the above embodiment or frame 1.

As described above, in this embodiment, the input television signal is divided into a plurality of small blocks by the block divider 8a, and the motion vector detector 9a obtains the motion vector of each small block. The detection means and the input television signal are divided by a block divider 8b into large blocks each having a size of the plurality of small blocks, and a large vector for obtaining a motion vector by each large block by a motion vector detector 9b. The motion vector detection means, the output determiner 10a, the limited range setting means for setting a limited range corresponding to each large vector with respect to the motion vector of each large block, and the number of small vectors of small blocks existing within the limited range. And a threshold setting means for setting a threshold for the output determination unit 1 when the number of small vectors exceeds the threshold.
0a is provided with a motion compensating means for outputting a large block video signal 16 and a large vector 17 inputted from the block divider 8b, so that when the small block erroneously detects the motion vector, the motion compensation is performed with the wrong motion vector. Is performed, and the motion vector becomes one large block motion vector, the motion vector coding efficiency is also improved.

Next, a third embodiment of the present invention will be described with reference to the drawings. In FIG. 3, 1 and 1a are subtractors, 2 is an orthogonal transformer, 3 is a quantizer, 4a and 4b are encoders, 5 is an inverse quantizer, 6 is an inverse orthogonal transformer, 7 is an adder, 8a and 8b are block dividers, 9a and 9b are motion vector detectors, 10b is an output determiner, and 11 is an input terminal.

With respect to the coding apparatus having the above-described components, the connection and operation of the components will be described.

Frame 1 input from input terminal 11
Is the motion vector detector 9a and the motion vector detector 9
Processing up to b is performed in the same manner as in the first embodiment. In this embodiment, the small vector detected by the motion vector detector 9a and the large vector detected by the motion vector detector 9b are
It is transmitted to the output determiner 10b and the subtractor 1a. Subtractor 1
At a, the difference between the large vector and the small vector (hereinafter referred to as the difference vector) is obtained and transmitted to the determiner 10b.
As in the case of the second embodiment, the determiner 10b sets a limited range for each large vector of each large block and sets the number of small vectors of the small blocks existing within the limited range. To set the threshold. Output determiner 10b
Outputs a video signal 19 of a small block, outputs the difference vector 20 input from the subtractor 1a when the number of small vectors exceeds the threshold, and outputs the small vector 20 when the number of small vectors is less than the threshold. . Output small block video signal 1
9 is processed in the same manner as in the first embodiment, and the output difference vector or small vector 20 is encoded by the encoder 4b and output as the encoded signal 21. Subsequent processing is the same as in the case of the first embodiment or frame 1.

As described above, in this embodiment, the input television signal is divided into a plurality of small blocks by the block divider 8a, and the motion vector detector 9a obtains the motion vector of each small block. The detection means and the input television signal are divided by a block divider 8b into large blocks each having a size of the plurality of small blocks, and a large vector for obtaining a motion vector by each large block by a motion vector detector 9b. The motion vector detection means, the output determiner 10b, the limited range setting means for setting a limited range corresponding to each large vector with respect to the motion vector of each large block, and the number of small vectors of small blocks existing within the limited range. And a threshold setting means for setting a threshold for the small blocks existing in the limited range when the number of small vectors exceeds the threshold. By including the motion vector coding means for coding the motion vector as a difference vector by the encoder 4b, the blocks within the limited range transmit the difference vector, and thus the motion vector coding efficiency is improved. Even when the transmitted difference vector is decoded, the difference value between each small vector and the large vector is obtained, so that error propagation can be prevented.

Next, a fourth embodiment of the present invention will be described with reference to the drawings. In FIG. 4, 1 and 1a are subtractors, 2 is an orthogonal transformer, 3 is a quantizer, 4a and 4b are encoders, 5 is an inverse quantizer, 6 is an inverse orthogonal transformer, 7 is an adder, 8a and 8b are block dividers, 9a and 9b are motion vector detectors, 10c is an output determiner, and 12 is an input terminal.

With respect to the encoding device having the above-described components, the mutual relation and operation of the components will be described below.

Frame 1 input from the input terminal 11
Is the motion vector detector 9a and the motion vector detector 9
Processing up to b is performed in the same manner as in the second embodiment. In the motion vector detector 9a and the motion vector detector 9b, the third
The processing is performed in the same manner as in the above embodiment, and the small vector and the large vector are output to the output determiner 10c and the subtractor 1a.
The subtracter 1a obtains the difference vector as in the third embodiment, and transmits the difference vector to the determiner 10c. Determiner 10c
Then, similarly to the case of the second embodiment, a limited range corresponding to each large vector is set for the large vector of each large block, and a threshold value is set for the number of small vectors of small blocks existing within the limited range. Set. When the number of small vectors exceeds the threshold, the output determiner 10c detects the motion vector detector 9b.
The difference vector 23 of the small block outside the limited range of the difference vector inputted from the subtractor 1a and the inputted large vector is outputted, and the video signal of the large block inputted from the block divider 8b and the limited range. The video signal 22 of the outer small block is output. The output video signal 22 is processed in the same manner as in the first embodiment, and the output motion vector 23 is encoded by the encoder 4b to obtain the encoded signal 2
It is output as 4. Subsequent processing is the same as in the case of the first embodiment or frame 1.

As described above, in this embodiment, the input television signal is divided into a plurality of small blocks by the block divider 8a, and the motion vector detector 9a obtains the motion vector of each small block. The detection means and the input television signal are divided by a block divider 8b into large blocks each having a size of the plurality of small blocks, and a large vector for obtaining a motion vector by each large block by a motion vector detector 9b. The motion vector detection means, the output determiner 10b, the limited range setting means for setting a limited range corresponding to each large vector with respect to the motion vector of each large block, and the number of small vectors of small blocks existing within the limited range. Threshold value setting means for setting a threshold value, and when the number of small vectors exceeds the threshold value, input from the motion vector detector 9b A large vector, a subtractor 1a
Of the input difference vectors, the difference vector 23 of the small blocks outside the limited range is output, and the block divider 8
Motion compensation is performed in the large block by outputting the large block video signal input from b and the small block video signal 22 outside the limited range, and the small block outside the limited range uses the difference vector of the large block. By providing the motion compensation means for performing motion compensation, it is possible to reduce the code amount of the motion vector and perform efficient coding.

In the second embodiment, the large vector is coded when the number of small blocks within the limited range exceeds the threshold value, but the average value of the small vectors may be used.

[0030]

As described above, according to the motion compensation coding apparatus of the present invention, the input television signal is divided into a plurality of small blocks, and the small block vector detecting means for obtaining the motion vector in each of the small blocks. And a large block vector detecting means that forms a large block from a plurality of the small blocks and obtains a motion vector in each of the large blocks,
For each motion vector obtained in each large block, a limited range setting means for setting a limited range according to the motion vector of each large block, and each motion vector of the small blocks in each large block, When existing within the limited range, using the motion vector of each large block,
By providing the motion compensation switching means for performing motion compensation and coding on the small blocks existing within the limited range, when a large number of similar motion vectors appear in the large block, they are treated as one vector. It is possible to reduce the difference value of the motion vector and improve the coding efficiency of the motion vector.

Threshold setting means for setting a threshold value for the number of motion vectors of the small blocks in each of the large blocks existing within the limited range, and movement of each of the large blocks when the motion vector exceeds the threshold value. By providing a motion compensation means for performing compensation, it is possible to prevent the small block from performing motion compensation with an incorrect motion vector when the motion vector detection is erroneous, and the motion vector becomes one motion vector of the large block. Therefore, the coding efficiency of the motion vector is also improved.

Further, the motion vector coding means for coding the motion vector of the small block existing within the limited range to obtain the difference value from the motion vector of each of the large blocks and coding the motion vector is provided. Since the blocks within the limited range transmit the difference vector, the coding efficiency of the motion vector is also improved, and even when the transmitted difference vector is decoded, each small vector obtains the difference value from the large vector. It is possible to prevent the propagation of error.

Further, there is provided a motion compensating means for carrying out motion compensation in each of the large blocks and performing motion compensation for each of the small blocks outside the limited range by using a difference vector from the motion vector of each of the large blocks. By this, it is possible to reduce the code amount of the motion vector and perform efficient coding.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a motion compensation encoding device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a motion compensation encoding device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a motion compensation encoding device according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a motion compensation encoding device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 1, 1a Subtractor 2 Orthogonal transformer 3 Quantizer 4a, 4b Encoder 5 Inverse quantizer 6 Inverse orthogonal transformer 7 Adder 8a, 8b Block divider 9a, 9b Motion vector detector 10, 10a, 10b , 10c Output determiner 11 Input terminal

Claims (7)

[Claims] Claim: What is claimed is: 1. A motion compensation coding apparatus for performing motion compensation coding for an input television signal using a motion vector indicating a motion amount and a direction of an image between frames (or between fields). The John signal is divided into multiple small blocks,
Small block vector detecting means for obtaining a motion vector in each of the small blocks, and a large block for dividing the input television signal into large blocks each having the size of the plurality of small blocks and obtaining a motion vector in each of the large blocks. Block vector detection means, with respect to the motion vector obtained in each large block, a limited range setting means for setting a limited range according to the motion vector of each large block, of the small blocks in each large block When each motion vector is within the limited range, using the motion vector of each large block, motion compensation switching encoding means for performing motion compensation and encoding for a small block within the limited range. A motion compensation encoding device comprising: 2. A motion compensation coding apparatus for performing motion compensation and coding of an input television signal using a motion vector indicating a motion amount and a direction of an image between frames (or between fields). The John signal is divided into multiple small blocks,
Small block vector detecting means for obtaining a motion vector in each of the small blocks, and a large block for dividing the input television signal into large blocks each having the size of the plurality of small blocks and obtaining a motion vector in each of the large blocks. Block vector detection means, a limited range setting means for setting a limited range corresponding to the motion vector of each large block, with respect to the motion vector obtained in each large block, each large range existing within the limited range. A threshold value setting means for setting a threshold value for the number of motion vectors of small blocks in the block; and a motion compensation means for performing motion compensation on each of the large blocks when the number of motion vectors exceeds the threshold value. Motion compensation coding device. 3. A motion compensation coding apparatus for performing motion compensation and coding of an input television signal using a motion vector indicating a motion amount and a direction of an image between frames (or between fields). The John signal is divided into multiple small blocks,
Small block vector detecting means for obtaining a motion vector in each of the small blocks, and a large block for dividing the input television signal into large blocks each having the size of the plurality of small blocks and obtaining a motion vector in each of the large blocks. Block vector detection means, a limited range setting means for setting a limited range corresponding to the motion vector of each large block, with respect to the motion vector obtained in each large block, each large range existing within the limited range. Threshold setting means for setting a threshold to the number of motion vectors of the small blocks in the block; and when the number of motion vectors exceeds the threshold, the motion vectors of the small blocks existing in the limited range are set to the large blocks. Motion vector coding means for calculating a difference value with respect to the motion vector and coding the motion vector. apparatus. 4. A motion compensation coding apparatus for performing motion compensation and coding of an input television signal by using a motion vector indicating a motion amount and a direction of an image between frames (or between fields). The John signal is divided into multiple small blocks,
Small block vector detecting means for obtaining a motion vector in each of the small blocks, and a large block for dividing the input television signal into large blocks each having the size of the plurality of small blocks and obtaining a motion vector in each of the large blocks. Block vector detection means, a limited range setting means for setting a limited range corresponding to the motion vector of each large block, with respect to the motion vector obtained in each large block, each large range existing within the limited range. Threshold setting means for setting a threshold to the number of motion vectors of small blocks in the block; and when the number of motion vectors exceeds the threshold, motion compensation is performed in each of the large blocks, and each small block outside the limited range. And a motion compensation means for performing motion compensation using a difference vector from the motion vector of each large block. Compensation coding device. 5. The motion compensation coding apparatus according to claim 1, 2 or 3 or 4, wherein the limited range is a magnitude of a motion vector. 6. A motion compensation coding apparatus according to claim 1, wherein the limited range is a direction of a motion vector. 7. The motion compensation coding apparatus according to claim 1, 2, 3 or 4, wherein the limited range is a magnitude and a direction of a motion vector.