Probability update method for binary arithmetic coding/decoding, and entropy coder/decoder using the same
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| Titel: | Probability update method for binary arithmetic coding/decoding, and entropy coder/decoder using the same |
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| Patent Number: | 10432,945 |
| Publikationsdatum: | October 01, 2019 |
| Appl. No: | 15/524327 |
| Application Filed: | November 04, 2015 |
| Abstract: | A probably update method used in context-based adaptive binary arithmetic coding (CABAC) is disclosed. The probably update method for binary arithmetic decoding obtains an autocorrelation value of each bin by using values of received bins, determines at least one scaling factor used to update a probability of a binary value based on the autocorrelation value, and updates a probability used in context-based adaptive binary arithmetic decoding by using the determined at least one scaling factor. |
| Inventors: | SAMSUNG ELECTRONICS CO., LTD. (Suwon-si, KR) |
| Assignees: | SAMSUNG ELECTRONICS CO., LTD. (Suwon-si, KR) |
| Claim: | 1. A probability update method for binary arithmetic decoding, the method comprising: receiving a predetermined number of bins that are to be binary arithmetic decoded; obtaining an autocorrelation value of each of the bins by using values of the received predetermined number of bins; determining at least one scaling factor used to update a probability of a binary value based on the autocorrelation value; updating a probability used in context-based adaptive binary arithmetic decoding by using the determined at least one scaling factor; and arithmetic decoding a current bin by using the updated probability, wherein the updating a probability comprises: obtaining the updated probability by adding a first value and a second value, the first value being obtained by multiplying a value based on the at least one scaling factor by a probability of a previous bin, and the second value being obtained by multiplying the at least one scaling factor by a value of a current bin, wherein when a value of the current bin is y (y is 0 or 1), a probability previous to the current bin is p(t−1) (t is an integer), the updated probability is p(t), and the at least one scaling factor is α, the updated probability p(t) is obtained according to an equation P(t)=αy+(1−α)*P(t−1). |
| Claim: | 2. The probability update method of claim 1 , wherein the at least one scaling factor is determined as a value having a minimum mean square error between a probability of each bin determined based on the autocorrelation value and a value of each bin. |
| Claim: | 3. The probability update method of claim 1 , wherein, when the autocorrelation value between the bins spaced by a predetermined distance k (k is an integer) is denoted by R k , an average value of the bins is denoted by M (M is a real number), a variance of the bins is denoted by σ, the number of bins is denoted by (N+1) (N is an integer), and values of (N+1) bins are denoted by y j (j is an integer from 0 to N), R k is obtained according to an equation [mathematical expression included] |
| Claim: | 4. The probability update method of claim 3 , wherein the scaling factor is one, and the one scaling factor α is obtained according to an equation [mathematical expression included] according to the obtained autocorrelation value R k . |
| Claim: | 5. The probability update method of claim 1 , wherein the scaling factors are two, and based on a value of the autocorrelation value R k , when R k ε[−1, 1/7], the two scaling factors α1 and α2 have a value of 0, [mathematical expression included] |
| Claim: | 6. The probability update method of claim 1 , wherein when the at least one scaling factor is plural, the plurality of scaling factors are denoted by α i , a value of the current bin is y (y is 0 or 1), a probability previous to the current bin is p(t−1) (t is an integer), and probabilities p i (t) updated according to the scaling factors α i are obtained according to an equation P i (t)=α i y+(1−α i)*P i (t−1), a weight average value of the plurality of updated probabilities p i (t) is used as a final update probability P(t). |
| Claim: | 7. A probability update method for binary arithmetic decoding, the method comprising: receiving a predetermined number of bins that are to be binary arithmetic decoded; obtaining entropy values indicating an average bit value of the bins by using a plurality of probability models having different scaling factors; determining a scaling factor of a probability model used to obtain a minimum entropy value among the plurality of probability models; updating a probability used in context-based adaptive binary arithmetic decoding by using the determined scaling factor; and performing context-based adaptive binary arithmetic decoding using the updated probability, wherein the updating a probability comprises: obtaining the updated probability by adding a first value and a second value, the first value being obtained by multiplying a value based on the at least one scaling factor by a probability of a previous bin, and the second value being obtained by multiplying the at least one scaling factor by a value of a current bin, wherein when a value of the current bin is y (y is 0 or 1), a probability previous to the current bin is p(t−1) (t is an integer), the updated probability is p(t), and the at least one scaling factor is α, the updated probability p(t) is obtained according to an equation P(t)=αy+(1−α)*P(t−1). |
| Claim: | 8. The probability update method of claim 7 , wherein when a value of a current bin is y, the scaling factors of the plurality of probability models are denoted by α i , a probability of the current bin is p i (t), and entropy obtained with respect to a previous bin is denoted by s i (t−1) of entropy of the current bin, the entropy s i (t) of the current bin is obtained according to an equation S i (t)=bit i *α i +(1−α i)*S i (t−1) by using a parameter bit i obtained according to an equation bit i =(y==1)?−log 2 p i (t):−log 2 (1−p i (t)). |
| Claim: | 9. An entropy decoding apparatus comprising: an inverse binarizer configured to map values of predetermined syntax elements to bins of a binary value; a context modeler configured to receive a predetermined number of bins that are to be binary arithmetic decoded, obtain an autocorrelation value of each bin by using values of the received predetermined number of bins, determine at least one scaling factor used to update a probability of a binary value based on the autocorrelation value, and update a probability used in context-based adaptive binary arithmetic decoding by using the determined at least one scaling factor; and a regular coder configured to arithmetic decode a current bin by using the updated probability, wherein the context modeler obtains the updated probability by adding a first value and a second value, the first value being obtained by multiplying a value based on the at least one scaling factor by a probability of a previous bin, and the second value being obtained by multiplying the at least one scaling factor by a value of a current bin, wherein when a value of the current bin is y (y is 0 or 1), a probability previous to the current bin is p(t−1) (t is an integer), the updated probability is p(t), and the at least one scaling factor is α, the updated probability p(t) is obtained according to an equation P(t)=αy+(1−α)*P(t−1). |
| Patent References Cited: | 7535387 May 2009 Delva 7573951 August 2009 Kim 9014260 April 2015 Alshin et al. 9036701 May 2015 Lainema et al. 9083374 July 2015 Marpe 9661326 May 2017 Alshin et al. 2009/0034856 February 2009 Moriya 2009/0123066 May 2009 Moriya 2009/0175331 July 2009 Karczewicz et al. 2011/0285557 November 2011 Korodi 2012/0328026 December 2012 Sole Rojals et al. 2013/0287120 October 2013 Kwon et al. 2013/0300591 November 2013 Marpe et al. 2014/0177708 June 2014 Alshin et al. 2016/0043735 February 2016 Zhou 2017/0339413 November 2017 Alshin et al. 1735209 February 2006 101106378 January 2008 102474599 May 2012 103181167 June 2013 103797803 May 2014 2760201 July 2014 1020130002298 January 2013 1020130122353 November 2013 2013002585 January 2013 |
| Other References: | Alshin, et al., “CE1 (subset B): Multi-parameter probability up-date for CABAC”, 2011, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, JCTVC-G764, 4 pages total, XP 030110748. cited by applicant Alshin, et al., “Multi-parameter probability up-date for CABAC”, 2011, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, JCTVC-F254, 5 pages total, XP 030009277. cited by applicant Communication dated Sep. 27, 2017, issued by the European Patent Office in counterpart European Patent Application No. 15857204.0. cited by applicant Communication dated Feb. 25, 2016, issued by the International Searching Authority in counterpart International Application No. PCT/KR2015/011794 (PCT/ISA/210 & PCT/ISA/237). cited by applicant Alexander Alshin et al: “High Precision Probability Estimation for CABAC”, Visual Communications and Image Processing (VCIP), Nov. 17-20, 2013, pp. 1-6, (6 pages total). cited by applicant Patent Examination Report No. 1 issued by the Australian IP Office in counterpart Australian Patent Application No. 2015343932 dated Apr. 15, 2019. cited by applicant Communication dated Jun. 25, 2019, from the State Intellectual Property Office of People's Republic of China in counterpart Application No. 201580071892.7. cited by applicant |
| Primary Examiner: | Anyikire, Chikaodili E |
| Attorney, Agent or Firm: | Sughrue Mion, PLLC |
| Dokumentencode: | edspgr.10432945 |
| Datenbank: | USPTO Patent Grants |
| Abstract: | A probably update method used in context-based adaptive binary arithmetic coding (CABAC) is disclosed. The probably update method for binary arithmetic decoding obtains an autocorrelation value of each bin by using values of received bins, determines at least one scaling factor used to update a probability of a binary value based on the autocorrelation value, and updates a probability used in context-based adaptive binary arithmetic decoding by using the determined at least one scaling factor. |
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