EP-4738830-A2 - MOVING PICTURE CODING METHOD, MOVING PICTURE DECODING METHOD, MOVING PICTURE CODING APPARATUS, MOVING PICTURE DECODING APPARATUS, AND MOVING PICTURE CODING AND DECODING APPARATUS

EP4738830A2EP 4738830 A2EP4738830 A2EP 4738830A2EP-4738830-A2

Abstract

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 (S11); 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 (S12), wherein the coded second and third information are placed after the coded first information in the bit stream.

Inventors

SASAI, HISAO
TERADA, KENGO
SHIBAHARA, YOUJI
TANIKAWA, KYOKO
SUGIO, TOSHIYASU
MATSUNOBU, TORU

Assignees

Sun Patent Trust

Dates

Publication Date: 20260506
Application Date: 20130517

Claims (3)

A moving picture coding method for coding an input image to generate a bitstream, the method comprising: performing (S11;S501) context adaptive binary arithmetic coding in which a variable probability value is used, on a part of sao_type_idx among multiple types of sample adaptive offset , SAO, information, wherein SAO 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 the part of sao_type_idx indicates whether SAO processing is to be performed; when the part of sao_type_idx indicates that SAO processing is to be performed, performing (S11;S503) bypass arithmetic coding, on an SAO offset, the SAO offset indicating an offset value; and after the bypass arithmetic coding on the SAO offset, performing (S12; S507, S509) bypass arithmetic coding on sao_offset_sign and sao_band_position among the multiple types of SAO information; wherein in the bypass arithmetic coding, a variable probability value is not used; the sao_band_position indicates a range of pixel values to which the SAO is applied; and the sao_offset_sign indicates whether the offset value is positive or negative characterized in that the sao_band_position is coded after the sao_offset_sign is coded; the sao_band_position and sao_offset_sign are placed after the coded sao_type_idx and SAO offset in the bitstream; and the sao_band_position is placed after the sao_offset_sign.
A moving picture coding apparatus which comprises control circuitry and storage accessible from the control circuitry, and which is adapted to code an input image to generate a bitstream; wherein the control circuitry is adapted to execute the moving picture coding method according to any of claims 1 to 4.
A streaming server for sending a bitstream coded by an image coding method according to claim 1.

Description

[Technical Field] The present invention relates to a moving picture coding method and a moving picture decoding method. [Background Art] The High Efficiency Video Coding (HEVC) standard, a next-generation image coding standard, has been examined in various ways to increase its coding efficiency (Non Patent Literature (NPL) 1). In addition, the International Telecommunication Union Telecommunication Standardization sector (ITU-T) standard typified by H.26x, and the ISO/IEC standard typified by MPEG-x exist conventionally. The latest and most advanced image coding standard has been examined as a standard next to a standard currently typified by H.264/AVC or MPEG-4 AVC (see Non Patent Literature (NPL) 2). In the HEVC standard, coding degradation reduction processing referred to as sample adaptive offset (SAO) has been examined to further reduce coding degradation (a difference between an original signal before coding and a coded and decoded signal). The SAO is offset processing in which an offset value is added for each of predetermined regions, categories, or types, to reduce the coding degradation, and is performed on a provisionally decoded image (reconstructed image) (see Non Patent Literature (NPL) 3). [Citation List] [Non Patent Literature] [NPL 1] Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11 9th Meeting: Geneva, CH, 27 April - 7 May 2012, JCTVC-I1003_d1, "High efficiency video coding (HEVC) text specification draft 7"[NPL 2] ITU-T Recommendation H.264 "Advanced video coding for generic audiovisual services", March, 2010[NPL 3] Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11 9th Meeting: Geneva, CH, 27 April - 7 May 2012, JCTVC-I0602, "BoG report on integrated text of SAO adoptions on top of JCTVC-I0030" [Summary of Invention] [Technical Problem] However, a moving picture coding method and a moving picture decoding method using the SAO of NPL 3 cannot make processing efficient. In view of this, one non-limiting and exemplary embodiment provides a moving picture coding method and a moving picture decoding method that can make processing efficient. [Solution to Problem] A moving picture coding method according to an aspect of the present invention is a moving picture coding method for coding an input image to generate a bit stream, the method including: 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. These general and specific aspects may be implemented using a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or any combination of systems, methods, integrated circuits, computer programs, or computer-readable recording media. [Advantageous Effects of Invention] A moving picture coding method and a moving picture decoding method in the present invention can make processing efficient. [Brief Description of Drawings] [FIG. 1A] FIG. 1A is a table showing information used for offset processing referred to as SAO.[FIG. 1B] FIG. 1B is a table showing other information used for offset processing referred to as SAO.[FIG. 1C] FIG. 1C is a table showing other information used for offset processing referred to as SAO.[FIG. 1D] FIG. 1D is a table showing other information used for offset processing referred to as SAO.[FIG. 2] FIG. 2 is a block diagram showing a functional configuration of a SAO information decoding unit.[FIG. 3] FIG. 3 is a flow chart showing an operation flow of the SAO information decoding unit.[FIG. 4] FIG. 4 is a flow chart showing context adaptive binary arithmetic decoding.[FIG. 5] FIG. 5 is a flow chart showing bypass arithmetic decoding.[FIG. 6] FIG. 6 is a flow chart showing a normalization process in an arithmetic decoding method.[FIG. 7] FIG. 7 is a block diagram showing an exemplary configuration of a moving picture decoding apparatus according to Embodiment 1.[FIG. 8] FIG. 8 is a block diagram showing a functional configuration of a SAO information decoding unit according to Embodiment 1.[FIG. 9] FIG. 9 is a flow chart showing arithmetic decoding by the SAO information decoding unit according to Embodiment 1.[FIG. 10A] FIG. 10A is a diagram for illustrating, in Embodiment 1, an exemplary sequence of parameters included in SAO information, and an exemplary decoding order of the parameters.[FIG. 10B] FIG. 10B is a diagram corresponding to the flow chart o