Picture coding device, picture coding method, picture coding program, transmitting device, transmitting method, and transmitting program

Abstract

In a case where a partition mode in which luma signals are partitioned horizontally and vertically is set when an intra prediction of a picture signal is made in units of minimal coding blocks set in advance, an intra prediction unit is configured to make an intra prediction of a chroma signal in units of prediction blocks of the intra prediction of chroma signals within the minimal coding block set in accordance with a chroma format. A second bitstream constructing unit constructs a bitstream of information relating to a luma intra prediction mode of a prediction block of luma signals and information relating to a chroma intra prediction mode of a prediction block of chroma signals.

What is claimed is: 
     
         1 . A picture coding device that performs intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and codes information relating to an intra prediction mode, the picture coding device comprising:
 a luma signal intra prediction unit configured to set first to fourth prediction blocks of luma signals acquired by partitioning a coding block of luma signals horizontally and vertically and predict a luma signal based on a coded neighboring block of luma signals in accordance with luma intra prediction modes for each prediction block of the luma signals, in a case where a partition mode in which a coding block of luma signals is partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in coding units;   a chroma signal intra prediction unit configured to set a prediction block of chroma signals without partitioning chroma signals of the coding block and predict a chroma signal based on a coded neighboring block of chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set; and   a bitstream constructing unit configured to encode information relating to the prediction mode of the coding block and encode a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals within the coding block, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and subsequently encode a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals so as to construct a bitstream in which information relating to prediction modes is arranged,   wherein the chroma signal intra prediction unit is configured to set a value indicating horizontal prediction in which a prediction direction is a horizontal direction as one of predefined values of the chroma intra prediction mode of the prediction block of the chroma signals, when the chroma intra prediction mode is not set in accordance with the luma intra prediction mode,   wherein the luma signal intra prediction unit, the chroma signal intra prediction unit, and the bitstream constructing unit are implemented using hardware, memory storing firmware, or a computer with software.   
     
     
         2 . A picture coding method for performing intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and coding information relating to an intra prediction mode, the picture coding method comprising:
 a luma signal intra prediction step of setting first to fourth prediction blocks of luma signals acquired by partitioning a coding block of luma signals horizontally and vertically and predicting a luma signal based on a coded neighboring block of luma signals in accordance with luma intra prediction modes for each prediction block of the luma signals, in a case where a partition mode in which a coding block of luma signals is partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in coding units;   a chroma signal intra prediction step of setting a prediction block of chroma signals without partitioning chroma signals of the coding block and predict a chroma signal based on a coded neighboring block of chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set; and   a bitstream constructing unit step of encoding information relating to the prediction mode of the coding block and encoding a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals within the coding block, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and subsequently encoding a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals so as to construct a bitstream in which information relating to prediction modes is arranged,   wherein the chroma signal intra prediction step sets a value indicating horizontal prediction in which a prediction direction is a horizontal direction as one of predefined values of the chroma intra prediction mode of the prediction block of the chroma signals, when the chroma intra prediction mode is not set in accordance with the luma intra prediction mode,   wherein the luma signal intra prediction step, the chroma signal intra prediction step, and the bitstream constructing step are performed using hardware, memory storing firmware, or a computer with software.   
     
     
         3 . A non-transitory computer-readable recording medium having embodied thereon a picture coding program for performing intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and coding information relating to an intra prediction mode, the picture coding program causing a computer to execute:
 a luma signal intra prediction step of setting first to fourth prediction blocks of luma signals acquired by partitioning a coding block of luma signals horizontally and vertically and predicting a luma signal based on a coded neighboring block of luma signals in accordance with luma intra prediction modes for each prediction block of the luma signals, in a case where a partition mode in which a coding block of luma signals is partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in coding units;   a chroma signal intra prediction step of setting a prediction block of chroma signals without partitioning chroma signals of the coding block and predict a chroma signal based on a coded neighboring block of chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set; and   a bitstream constructing unit step of encoding information relating to the prediction mode of the coding block and encoding a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals within the coding block, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and subsequently encoding a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals so as to construct a bitstream in which information relating to prediction modes is arranged,   wherein the chroma signal intra prediction step sets a value indicating horizontal prediction in which a prediction direction is a horizontal direction as one of predefined values of the chroma intra prediction mode of the prediction block of the chroma signals, when the chroma intra prediction mode is not set in accordance with the luma intra prediction mode.   
     
     
         4 . A transmitting device comprising:
 a packet processing unit configured to derive a bitstream by packetizing a bitstream coded by using a picture coding method for performing intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and coding information relating to an intra prediction mode; and   a transmitting unit configured to transmit the packetized bitstream, wherein   the picture coding method comprising:   a luma signal intra prediction step of setting first to fourth prediction blocks of luma signals acquired by partitioning a coding block of luma signals horizontally and vertically and predicting a luma signal based on a coded neighboring block of luma signals in accordance with luma intra prediction modes for each prediction block of the luma signals, in a case where a partition mode in which a coding block of luma signals is partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in coding units;   a chroma signal intra prediction step of setting a prediction block of chroma signals without partitioning chroma signals of the coding block and predict a chroma signal based on a coded neighboring block of chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set; and   a bitstream constructing unit step of encoding information relating to the prediction mode of the coding block and encoding a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals within the coding block, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and subsequently encoding a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals so as to construct a bitstream in which information relating to prediction modes is arranged,   wherein the chroma signal intra prediction step sets a value indicating horizontal prediction in which a prediction direction is a horizontal direction as one of predefined values of the chroma intra prediction mode of the prediction block of the chroma signals, when the chroma intra prediction mode is not set in accordance with the luma intra prediction mode,   wherein the luma signal intra prediction step, the chroma signal intra prediction step, and the bitstream constructing step are performed using hardware, memory storing firmware, or a computer with software.   
     
     
         5 . A transmitting method comprising:
 a packet processing step of deriving a bitstream by packetizing a bitstream coded by using a picture coding method for performing intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and coding information relating to an intra prediction mode; and   a transmitting step of transmitting the packetized bitstream, wherein   the picture coding method comprising:   a luma signal intra prediction step of setting first to fourth prediction blocks of luma signals acquired by partitioning a coding block of luma signals horizontally and vertically and predicting a luma signal based on a coded neighboring block of luma signals in accordance with luma intra prediction modes for each prediction block of the luma signals, in a case where a partition mode in which a coding block of luma signals is partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in coding units;   a chroma signal intra prediction step of setting a prediction block of chroma signals without partitioning chroma signals of the coding block and predict a chroma signal based on a coded neighboring block of chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set; and   a bitstream constructing unit step of encoding information relating to the prediction mode of the coding block and encoding a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals within the coding block, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and subsequently encoding a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals so as to construct a bitstream in which information relating to prediction modes is arranged,   wherein the chroma signal intra prediction step sets a value indicating horizontal prediction in which a prediction direction is a horizontal direction as one of predefined values of the chroma intra prediction mode of the prediction block of the chroma signals, when the chroma intra prediction mode is not set in accordance with the luma intra prediction mode,   wherein the packet processing step, the transmitting step, the luma signal intra prediction step, the chroma signal intra prediction step, and the bitstream constructing step are performed using hardware, memory storing firmware, or a computer with software.   
     
     
         6 . A non-transitory computer-readable recording medium having embodied thereon a transmitting program causing a computer to execute:
 a packet processing step of deriving a bitstream by packetizing a bitstream coded by using a picture coding method for performing intra prediction coding of a picture signal including a luma signal and a chroma signal in units of blocks and coding information relating to an intra prediction mode; and   a transmitting step of transmitting the packetized bitstream, wherein   the picture coding method comprising:   a luma signal intra prediction step of setting first to fourth prediction blocks of luma signals acquired by partitioning a coding block of luma signals horizontally and vertically and predicting a luma signal based on a coded neighboring block of luma signals in accordance with luma intra prediction modes for each prediction block of the luma signals, in a case where a partition mode in which a coding block of luma signals is partitioned horizontally and vertically is set when an intra prediction of the picture signal is made in coding units;   a chroma signal intra prediction step of setting a prediction block of chroma signals without partitioning chroma signals of the coding block and predict a chroma signal based on a coded neighboring block of chroma signals in accordance with a chroma intra prediction mode in a case where the partition mode is set; and   a bitstream constructing unit step of encoding information relating to the prediction mode of the coding block and encoding a syntax element relating to the luma intra prediction mode of the first prediction block of luma signals within the coding block, a syntax element relating to the luma intra prediction mode of the second prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the third prediction block of luma signals, a syntax element relating to the luma intra prediction mode of the fourth prediction block of luma signals, and subsequently encoding a syntax element relating to the chroma intra prediction mode of the prediction block of chroma signals that is located at a reference position that is the same as the position of the first prediction block of luma signals so as to construct a bitstream in which information relating to prediction modes is arranged,   wherein the chroma signal intra prediction step sets a value indicating horizontal prediction in which a prediction direction is a horizontal direction as one of predefined values of the chroma intra prediction mode of the prediction block of the chroma signals, when the chroma intra prediction mode is not set in accordance with the luma intra prediction mode,   wherein the luma signal intra prediction step, the chroma signal intra prediction step, and the bitstream constructing step are performed using hardware, memory storing firmware, or a computer with software.