JP2014011482A5

JP2014011482A5 -

Info

Publication number: JP2014011482A5
Application number: JP2012144322A
Authority: JP
Filing date: 2012-06-27
Publication date: 2015-09-10
Anticipated expiration: 2032-06-27

Description

上述課題を解決するため、本発明の画像符号化装置は以下の構成を有する。即ち、入力された画像を複数のブロックに分割し、符号化対象のブロックと参照する画素とを用いて予測誤差を生成する予測手段と、前記予測誤差に直交変換を施し、変換係数を生成する変換手段と、前記変換係数又は前記予測誤差を、前記符号化対象のブロックに対応する量子化マトリクスを用いて量子化することにより、量子化係数を生成する量子化手段と、前記量子化係数を符号化する第１符号化手段と、前記符号化対象のブロックに対応する量子化マトリクスが、所定の量子化マトリクスである場合には、前記符号化対象のブロックに対応する量子化マトリクスが前記所定の量子化マトリクスであることを示す第１情報を符号化する第２符号化手段とを有する。In order to solve the above-described problems, an image encoding apparatus according to the present invention has the following configuration. That is, the input image is divided into a plurality of blocks, a prediction unit that generates a prediction error using a block to be encoded and a reference pixel, and orthogonal transformation is performed on the prediction error to generate a transform coefficient. A quantizing means for generating a quantized coefficient by quantizing the transform coefficient, the transform coefficient or the prediction error using a quantization matrix corresponding to the block to be encoded; and the quantized coefficient When the first encoding means for encoding and the quantization matrix corresponding to the encoding target block are a predetermined quantization matrix, the quantization matrix corresponding to the encoding target block is the predetermined quantization matrix. And a second encoding means for encoding the first information indicating that it is a quantization matrix.

さらに、本発明の画像復号装置は以下の構成を有する。即ち、入力されたビットストリームであって、符号化された画像のデータを含むビットストリームのうち、復号対象の量子化係数の符号を復号することによって量子化係数を再生する第１復号手段と、前記量子化係数を逆量子化する際に用いる量子化マトリクスであって復号対象の量子化マトリクスが、所定の量子化マトリクスである場合には、前記復号対象の量子化マトリクスが前記所定の量子化マトリクスであることを示す第１情報を復号する第２復号手段と、前記第２復号手段によって復号された前記第１情報を用いて、前記第１復号手段によって再生された量子化係数を逆量子化することによって、変換係数を生成する逆量子化手段と、前記変換係数を逆変換することにより得られた予測誤差から画像を復元する再構成手段とを有する。 Furthermore, the image decoding apparatus of the present invention has the following configuration. That is, a first decoding unit that reproduces a quantized coefficient by decoding a code of a quantized coefficient to be decoded from an input bit stream that includes encoded image data; When the quantization matrix used for inverse quantization of the quantization coefficient and the quantization matrix to be decoded is a predetermined quantization matrix, the quantization matrix to be decoded is the predetermined quantization matrix. Using the second decoding means for decoding the first information indicating that it is a matrix and the first information decoded by the second decoding means, the quantization coefficient reproduced by the first decoding means is dequantized. And a re-quantization means for generating a transform coefficient and a reconstruction means for restoring an image from a prediction error obtained by inverse transform of the transform coefficient. .

Claims

A prediction unit that divides an input image into a plurality of blocks and generates a prediction error using a block to be encoded and a pixel to be referenced;
Conversion means for said applying Cartesian transformation to the prediction error, and generates a transform coefficient,
The transform coefficients or the prediction error, by using a quantization matrix corresponding to a block of the encoding target, and quantization means for generating quantized coefficients,
First encoding means for encoding the quantized coefficients ;
It indicates that the quantization matrix corresponding to a block of the encoding target, if it is predetermined quantization Matrix scan the quantization matrix corresponding to a block of the encoding target is said predetermined quantization matrix An image encoding apparatus comprising: a second encoding unit that encodes the first information.

The second encoding means includes
When the quantization matrix corresponding to the block to be encoded is the same as any one of the plurality of the predetermined quantization matrices , the plurality of the predetermined quantization matrices , Encode second information indicating the same quantization matrix as the quantization matrix corresponding to the block to be encoded ,
Encoding a coefficient included in a quantization matrix corresponding to the block to be encoded when a quantization matrix corresponding to the block to be encoded is not the same as a plurality of the predetermined quantization matrices. The image encoding apparatus according to claim 1, wherein the apparatus is an image encoding apparatus.

Furthermore, it has storage means for storing in advance the predetermined quantization matrix that can be used by the quantization means,
The second encoding unit includes a first quantization matrix in which a quantization matrix corresponding to the block to be encoded is a quantization matrix stored in the storage unit, and the coefficients are all the same, and the storage unit Any one of a second quantization matrix that includes coefficients of different values and a third quantization matrix corresponding to a block encoded before the encoding target block of the case is identical to the quantization matrix, the image coding apparatus according to the first information to claim 1 or 2, characterized in that encoding.

Further, the and determines conversion control means whether to perform an orthogonal transform on the prediction error,
By the conversion control unit, when it is determined not to perform an orthogonal transform on the prediction error, and having a <br/> row cormorants adjustment means adjusts said prediction error bit depth The image coding apparatus according to any one of claims 1 to 3.

5. The image encoding apparatus according to claim 4, further comprising third encoding means for encoding third information indicating a determination result of whether or not to perform orthogonal transform on the prediction error.

The prediction and quantization matrix used to quantize the transform coefficients which is the output of the converting means when the error performs orthogonal transform on the previous SL When not performing an orthogonal transform on the prediction means adjusting the quantization matrix used to quantize the prediction error bit depth adjustment, which is the output of the integer unit, the image encoding apparatus according to claim 4, characterized in that the same.

When the quantization matrix corresponding to the encoding target block is the same as the predetermined quantization matrix, the second encoding means includes a coefficient included in the quantization matrix corresponding to the encoding target block. The image encoding apparatus according to claim 2, wherein the first information and the second information are encoded without encoding.

A prediction unit that divides an input image into a plurality of blocks and generates a prediction error using a block to be encoded and a pixel to be referenced;
Transform means for performing orthogonal transform on the prediction error and generating transform coefficients;
Quantization means for generating a quantized coefficient by quantizing the transform coefficient or the prediction error using a quantization matrix corresponding to the block to be encoded and comprising a plurality of coefficients When,
First encoding means for encoding the quantized coefficients;
A second code that encodes information indicating whether or not each coefficient of a quantization matrix corresponding to the block to be encoded is the same value, which is used for quantization by the quantization means And means
An image encoding apparatus comprising:

A first decoding unit that reproduces a quantized coefficient by decoding a code of a quantized coefficient to be decoded from a bit stream that is an input bit stream and includes encoded image data ;
The quantization matrix to be decoded to a quantization matrix used when inverse quantization of the quantized coefficients, when a predetermined quantization Matrix scan is the decoding target of the quantization matrix of the predetermined quantum Second decoding means for decoding the first information indicating that it is a generalized matrix ;
Using the first information decoded by said second decoding means, by inverse quantizing the quantized coefficients reproduced by said first decoding means, and inverse quantization means for generating transform coefficients,
An image decoding apparatus comprising: reconstruction means for restoring an image from a prediction error obtained by inversely transforming the transform coefficient.

The second decoding means includes
When the decoding target quantization matrix is the same as any one of the plurality of predetermined quantization matrices, the decoding target quantization matrix among the plurality of predetermined quantization matrices And decoding the second information indicating the same quantization matrix,
When the quantization matrix to be decoded is not the same as a plurality of the predetermined quantization matrices, the coefficient included in the quantization matrix to be decoded is decoded,
The inverse quantization means is reproduced by the first decoding means using the coefficients included in the quantization matrix to be decoded decoded by the second decoding means, or the first information and the second information. The image decoding apparatus according to claim 9, wherein a transform coefficient is generated by dequantizing the quantized coefficient.

Furthermore, it has a storage means for storing in advance the predetermined quantization matrix that can be used by the inverse quantization means,
The second decoding means includes: a first quantization matrix in which the quantization matrix to be decoded is a quantization matrix stored in the storage means and the coefficients are all the same; and a quantization stored in the storage means A second quantization matrix, which is a matrix and includes coefficients of different values, and a first quantization matrix used for decoding and dequantizing the code of the quantized coefficient decoded before the code of the quantization coefficient to be decoded The image decoding device according to claim 9 or 10, wherein the first information is decoded when one of the three quantization matrices is the same as any one of the quantization matrices.

Further, the reverse conversion control means determines whether to perform the inverse orthogonal transform on the inverse quantized coefficients is output from the inverse quantization means,
By the inverse transform control unit, claims wherein when it is determined not to perform inverse orthogonal transform on the prediction error, and having an adjusting means for performing adjustment of the bit depth of the inverse quantization coefficients The image decoding device according to any one of claims 9 to 11 .

Furthermore, we have a third decoding means for decoding the information indicating the determination result of whether to perform the inverse orthogonal transform to the dequantized coefficients,
13. The image decoding apparatus according to claim 12 , wherein the inverse transform control unit makes a determination based on information decoded by the third decoding unit .

When the decoding target quantization matrix is the same as the predetermined quantization matrix, the second decoding unit does not decode the coefficient included in the decoding target quantization matrix, and the first information and The image decoding apparatus according to claim 10, wherein the second information is decoded.

A first decoding unit that reproduces a quantized coefficient by decoding a code of a quantized coefficient to be decoded from a bit stream that is an input bit stream and includes encoded image data;
Second decoding means for decoding information indicating whether each coefficient of a quantization matrix used when dequantizing the quantization coefficient is the same value;
Dequantizing means for generating transform coefficients by dequantizing the quantized coefficients using a quantization matrix based on the information decoded by the second decoding means;
A prediction error generated by inversely transforming the transform coefficient, or reconstruction means for restoring an image from the transform coefficient;
An image decoding apparatus comprising:

A prediction step of dividing the input image into a plurality of blocks, generating a prediction error using a pixel to reference block to be coded,
A conversion step of the subjecting the Cartesian transformation to the prediction error, and generates a transform coefficient,
The transform coefficients or the prediction error, by using a quantization matrix corresponding to a block of the encoding target, a quantization step to generate a quantized coefficient,
A first encoding step for encoding the quantized coefficients ;
It indicates that the quantization matrix corresponding to a block of the encoding target, if it is predetermined quantization Matrix scan the quantization matrix corresponding to a block of the encoding target is said predetermined quantization matrix An image encoding method comprising: a second encoding step for encoding the first information.

A entered bit stream, of the bit stream containing the data of the encoded image, the first decoding step for reproducing the quantization coefficients by decoding the coding of the quantized coefficients to be decoded,
The quantization matrix to be decoded to a quantization matrix used when inverse quantization of the quantized coefficients, when a predetermined quantization Matrix scan is the decoding target of the quantization matrix of the predetermined quantum A second decoding step of decoding the first information indicating that it is a generalized matrix ;
Using the first information decoded by said second decoding step, by inverse quantizing the quantized coefficients reproduced by said first decoding step, a dequantization step of generating transform coefficients,
An image decoding method comprising: a reconstruction step of restoring an image from a prediction error obtained by inversely transforming the transform coefficient.

A program that causes a computer to function as the image encoding device according to any one of claims 1 to 8, when the computer reads and executes the program.

A program that causes a computer to function as the image decoding device according to any one of claims 9 to 15 when the computer reads and executes the program.