Moving picture coding method, moving picture decoding method, moving picture coding apparatus, moving picture decoding apparatus, and moving picture coding and decoding apparatus
A moving picture coding method includes: performing context adaptive binary arithmetic coding in which a variable probability value is used, on first information among multiple types of sample adaptive offset (SAO) information used for SAO that is a process of assigning an offset value to a pixel value of a pixel included in an image generated by coding the input image; and continuously performing bypass arithmetic coding in which a fixed probability value is used, on second information and third information among the multiple types of the SAO information, wherein the coded second and third information are placed after the coded first information in the bit stream.
1. A moving picture decoding method for decoding a coded image included in a bit stream, the method comprising:
performing context adaptive binary arithmetic decoding in which a variable probability value is used on, from among multiple types of sample adaptive offset (SAO) information that are included in the bit stream and used for SAO which is a process of assigning an offset value to a pixel value of a pixel included in an image generated by decoding the coded image, part of coded sao_type_idx indicating that the SAO is not to be performed; and
continuously performing bypass arithmetic decoding in which a fixed probability value is used on, from among the multiple types of the SAO information, (i) coded sao_band_position indicating a range of pixel values to which the SAO is applied and (ii) coded sao_offset_sign indicating whether the offset value is positive or negative,
wherein in the bitstream, the coded sao_band_position and the coded sao_offset_sign are located after the coded sao_type_idx, and
wherein a variable probability is not used in the bypass arithmetic decoding.
2. The moving picture decoding method according to claim 1 ,
wherein in the continuously performing the bypass arithmetic decoding, the bypass arithmetic decoding is performed on the coded sao_band_position after the bypass arithmetic decoding is performed on the coded sao_offset_sign and without performing the context adaptive binary arithmetic decoding on information after the bypass arithmetic decoding is performed on the coded sao_offset_sign.
3. A moving picture decoding apparatus for decoding a coded image included in a bit stream, the moving picture decoding apparatus comprising:
a processing circuitry; and
a storage coupled to the processing circuitry,
wherein the processing circuitry performs the following using the storage:
performing context adaptive binary arithmetic decoding in which a variable probability value is used on, from among multiple types of sample adaptive offset (SAO) information that are included in the bit stream and used for SAO that is a process of assigning an offset value to a pixel value of a pixel included in an image generated by decoding the coded image, part of coded sao_type_idx indicating that the SAO is not to be performed; and
continuously performing bypass arithmetic decoding in which a fixed probability value is used on, from among the multiple types of the SAO information, (i) coded sao_band_position indicating a range of pixel values to which the SAO is applied and (ii) coded sao_offset_sign indicating whether the offset value is positive or negative,
wherein in the bitstream, the coded sao_band_position and the coded sao_offset_sign are located after the coded sao_type_idx, and
wherein a variable probability is not used in the bypass arithmetic decoding.
4. A moving picture decoding apparatus for decoding a coded image included in a bit stream, the moving picture decoding apparatus comprising:
a context adaptive binary arithmetic decoding unit that performs context adaptive binary arithmetic decoding in which a variable probability value is used on, from among multiple types of sample adaptive offset (SAO) information that are included in the bit stream and used for SAO which is a process of assigning an offset value to a pixel value of a pixel included in an image generated by decoding the coded image, part of coded sao_type_idx indicating that the SAO is not to be performed; and
a bypass arithmetic decoding unit that continuously performs bypass arithmetic decoding in which a fixed probability value is used on, from among the multiple types of the SAO information, (i) coded sao_band_position indicating a range of pixel values to which the SAO is applied and (ii) coded sao_offset_sign indicating whether the offset value is positive or negative,
wherein in the bitstream, the coded sao_band_position and the coded sao_offset_sign are located after the coded sao_type_idx, and
wherein a variable probability is not used in the bypass arithmetic decoding.