JP2014220786A5

JP2014220786A5 -

Info

Publication number: JP2014220786A5
Application number: JP2014023252A
Authority: JP
Filing date: 2014-02-10
Publication date: 2016-01-28
Anticipated expiration: 2034-02-10

Description

上記課題を解決するために、本発明のある態様の画像復号装置は、予測ブロック単位でイントラ予測モードに関する情報を復号して、変換ブロック単位で輝度信号と色差信号とを含む画像信号をイントラ予測を用いて復号する画像復号装置であって、輝度信号の予測ブロックのイントラ予測方法を示すイントラ輝度予測モードに関する情報が符号化された符号化ストリームから、輝度信号のイントラ予測モードに関するシンタックス要素を復号し、輝度信号のイントラ予測モードを導出するイントラ輝度予測モード復号部（２２２、２２４）と、色差信号の予測ブロックのイントラ予測方法を示すイントラ色差予測モードに関する情報が符号化された符号化ストリームから、色差信号のイントラ色差予測モードに関するシンタックス要素を復号し、前記イントラ輝度予測モードも参照して、第１イントラ色差予測モードを導出するイントラ色差予測モード復号部（２２２、２２５）と、前記輝度信号の予測ブロック毎に特定されたイントラ輝度予測モードに応じて、輝度信号の変換ブロックの周囲の輝度信号から前記輝度信号の変換ブロックの輝度信号を予測する輝度信号イントラ予測部（２０６）と、前記色差信号の予測ブロック毎に特定されたイントラ色差予測モードに応じて、色差信号の変換ブロックの周囲の色差信号から前記色差信号の変換ブロックの色差信号を予測する色差信号イントラ予測部（２０６）とを備える。前記イントラ色差予測モード復号部（２２２、２２５）は、前記輝度信号と前記色差信号の画素のアスペクト比が異なる場合、前記アスペクト比が同じ場合に使用する第１イントラ色差予測モードのモード番号を変換して、前記アスペクト比が異なる場合に使用する第２イントラ色差予測モードを導出する。 In order to solve the above problems, an image decoding apparatus according to an aspect of the present invention decodes information related to an intra prediction mode in units of prediction blocks, and performs intra prediction on an image signal including a luminance signal and a color difference signal in units of transform blocks. And a syntax element related to an intra prediction mode of a luminance signal from an encoded stream in which information about the intra luminance prediction mode indicating an intra prediction method of a prediction block of the luminance signal is encoded. An intra-brightness prediction mode decoding unit (222, 224) that decodes and derives an intra-prediction mode of the luminance signal, and an encoded stream in which information on the intra-chrominance prediction mode indicating the intra-prediction method of the prediction block of the chrominance signal is encoded To the syntax element related to the intra color difference prediction mode of the color difference signal. And the intra brightness prediction modes with reference, intra chrominance prediction mode decoding unit that derives a first intra chrominance prediction mode (222, 225), the intra luminance prediction mode specified for each prediction block of the luminance signal Accordingly, a luminance signal intra prediction unit (206) that predicts the luminance signal of the luminance signal conversion block from luminance signals around the luminance signal conversion block, and intra color difference prediction specified for each prediction block of the color difference signal A color difference signal intra prediction unit (206) that predicts the color difference signal of the color difference signal conversion block from the color difference signals around the color difference signal conversion block according to the mode. The intra color difference prediction mode decoding unit (222, 225) converts the mode number of the first intra color difference prediction mode used when the aspect ratios of the pixels of the luminance signal and the color difference signal are different when the aspect ratios are the same. Then, the second intra color difference prediction mode used when the aspect ratios are different is derived.

本発明の別の態様は、画像復号方法である。この方法は、予測ブロック単位でイントラ予測モードに関する情報を復号して、変換ブロック単位で輝度信号と色差信号とを含む画像信号をイントラ予測を用いて復号する画像復号方法であって、輝度信号の予測ブロックのイントラ予測方法を示すイントラ輝度予測モードに関する情報が符号化された符号化ストリームから、輝度信号のイントラ予測モードに関するシンタックス要素を復号し、輝度信号のイントラ予測モードを導出するイントラ輝度予測モード復号ステップと、色差信号の予測ブロックのイントラ予測方法を示すイントラ色差予測モードに関する情報が符号化された符号化ストリームから、色差信号のイントラ色差予測モードに関するシンタックス要素を復号し、前記イントラ輝度予測モードも参照して、第１イントラ色差予測モードを導出するイントラ色差予測モード復号ステップと、前記輝度信号の予測ブロック毎に特定されたイントラ輝度予測モードに応じて、輝度信号の変換ブロックの周囲の輝度信号から前記輝度信号の変換ブロックの輝度信号を予測する輝度信号イントラ予測ステップと、前記色差信号の予測ブロック毎に特定されたイントラ色差予測モードに応じて、色差信号の変換ブロックの周囲の色差信号から前記色差信号の変換ブロックの色差信号を予測する色差信号イントラ予測ステップとを備える。前記イントラ色差予測モードステップは、前記輝度信号と前記色差信号の画素のアスペクト比が異なる場合、前記アスペクト比が同じ場合に使用する第１イントラ色差予測モードのモード番号を変換して、前記アスペクト比が異なる場合に使用する第２イントラ色差予測モードを導出する。 Another aspect of the present invention is an image decoding method. This method is an image decoding method that decodes information related to an intra prediction mode in units of prediction blocks, and decodes an image signal including a luminance signal and a color difference signal in units of transform blocks using intra prediction. Intra luminance prediction for decoding an intra prediction mode of a luminance signal by decoding a syntax element related to the intra prediction mode of a luminance signal from an encoded stream in which information on the intra luminance prediction mode indicating a prediction method of a prediction block is encoded Decoding the syntax element related to the intra color difference prediction mode of the color difference signal from the encoded stream in which the information related to the intra color difference prediction mode indicating the mode decoding step and the intra prediction method of the prediction block of the color difference signal is encoded; see also the prediction mode, the first intra chrominance An intra-color-difference prediction mode decoding step for deriving a measurement mode, and the luminance signal conversion block from the luminance signal around the luminance signal conversion block according to the intra-luminance prediction mode specified for each prediction block of the luminance signal. According to the luminance signal intra prediction step for predicting the luminance signal and the intra color difference prediction mode specified for each prediction block of the color difference signal, the color difference of the color difference signal conversion block from the color difference signal around the color difference signal conversion block A color difference signal intra prediction step for predicting a signal. The intra color difference prediction mode step converts the mode number of the first intra color difference prediction mode to be used when the aspect ratio of the pixels of the luminance signal and the color difference signal is different, and the aspect ratio is the same. The second intra color difference prediction mode to be used when is different is derived.

Claims

An image decoding apparatus that decodes information related to an intra prediction mode in units of prediction blocks and decodes an image signal including a luminance signal and a color difference signal in units of transform blocks using intra prediction,
The syntax element related to the intra prediction mode of the luminance signal is decoded from the encoded stream in which the information related to the intra luminance prediction mode indicating the intra prediction method of the prediction block of the luminance signal is encoded, and the intra prediction mode of the luminance signal is derived. An intra luminance prediction mode decoding unit;
The syntax element related to the intra color difference prediction mode of the color difference signal is decoded from the encoded stream in which the information related to the intra color difference prediction mode indicating the intra prediction method of the prediction block of the color difference signal is encoded, and the intra luminance prediction mode is also referred to. Te, and the intra chrominance prediction mode decoding unit that derives a first intra chrominance prediction mode,
A luminance signal intra prediction unit that predicts the luminance signal of the conversion block of the luminance signal from the luminance signal around the conversion block of the luminance signal according to the intra luminance prediction mode specified for each prediction block of the luminance signal;
Depending on the identified intra chrominance prediction mode for each prediction block of the color difference signals, and a chrominance signal intra prediction unit for predicting a color difference signal of the transform block of the color difference signals from the color difference signals of the surrounding transform blocks of the color difference signals ,
The intra color difference prediction mode decoding unit converts a mode number of a first intra color difference prediction mode to be used when the aspect ratios of the pixels of the luminance signal and the color difference signal are different, and the aspect ratio is the same. An image decoding apparatus that derives a second intra color difference prediction mode to be used when the ratio is different .

An image decoding method for decoding information on an intra prediction mode in units of prediction blocks and decoding an image signal including a luminance signal and a color difference signal in units of transform blocks using intra prediction,
The syntax element related to the intra prediction mode of the luminance signal is decoded from the encoded stream in which the information related to the intra luminance prediction mode indicating the intra prediction method of the prediction block of the luminance signal is encoded, and the intra prediction mode of the luminance signal is derived. An intra luminance prediction mode decoding step;
The syntax element related to the intra color difference prediction mode of the color difference signal is decoded from the encoded stream in which the information related to the intra color difference prediction mode indicating the intra prediction method of the prediction block of the color difference signal is encoded, and the intra luminance prediction mode is also referred to. Te, and the intra chrominance prediction mode decoding step of deriving a first intra chrominance prediction mode,
A luminance signal intra prediction step for predicting a luminance signal of the luminance signal conversion block from luminance signals around the luminance signal conversion block according to an intra luminance prediction mode specified for each prediction block of the luminance signal;
Yes Depending on the identified intra chrominance prediction mode for each prediction block of the color difference signal and a chrominance signal intra prediction step for predicting the color difference signals of the transform block of the color difference signals from the color difference signals of the surrounding transform blocks of the color difference signals And
The intra chrominance prediction mode decoding step converts the mode number of the first intra chrominance prediction mode to be used when the aspect ratios of the pixels of the luminance signal and the chrominance signal are different, and the aspect ratio is the same. An image decoding method characterized by deriving a second intra color difference prediction mode to be used when the ratios are different .

An image decoding program that decodes information about an intra prediction mode in units of prediction blocks and decodes an image signal including a luminance signal and a color difference signal in units of transform blocks using intra prediction,
The syntax element related to the intra prediction mode of the luminance signal is decoded from the encoded stream in which the information related to the intra luminance prediction mode indicating the intra prediction method of the prediction block of the luminance signal is encoded, and the intra prediction mode of the luminance signal is derived. An intra luminance prediction mode decoding step;
The syntax element related to the intra color difference prediction mode of the color difference signal is decoded from the encoded stream in which the information related to the intra color difference prediction mode indicating the intra prediction method of the prediction block of the color difference signal is encoded, and the intra luminance prediction mode is also referred to. Te, and the intra chrominance prediction mode decoding step of deriving a first intra chrominance prediction mode,
A luminance signal intra prediction step for predicting a luminance signal of the luminance signal conversion block from luminance signals around the luminance signal conversion block according to an intra luminance prediction mode specified for each prediction block of the luminance signal;
Depending on the identified intra chrominance prediction mode for each prediction block of the color difference signal, a computer and a chrominance signal intra prediction step for predicting the color difference signals of the transform block of the color difference signals from the color difference signals of the surrounding transform blocks of the color difference signals To run
The intra chrominance prediction mode decoding step converts the mode number of the first intra chrominance prediction mode to be used when the aspect ratios of the pixels of the luminance signal and the chrominance signal are different, and the aspect ratio is the same. An image decoding program for deriving a second intra color difference prediction mode to be used when the ratios are different .