EP 3183879 A1 20170628 - METHOD FOR ENCODING A DIGITAL IMAGE, AND ASSOCIATED DECODING METHOD, DEVICES AND COMPUTER PROGRAMMES
Title (en)
METHOD FOR ENCODING A DIGITAL IMAGE, AND ASSOCIATED DECODING METHOD, DEVICES AND COMPUTER PROGRAMMES
Title (de)
VERFAHREN ZUR CODIERUNG EINES DIGITALEN BILDES UND ZUGEHÖRIGES DECODIERUNGSVERFAHREN, VORRICHTUNGEN UND COMPUTERPROGRAMME
Title (fr)
PROCÉDÉ DE CODAGE D'UNE IMAGE NUMÉRIQUE, PROCÉDÉ DE DÉCODAGE, DISPOSITIFS, ET PROGRAMMES D'ORDINATEURS ASSOCIÉS
Publication
Application
Priority
- FR 1456032 A 20140627
- FR 2015051587 W 20150616
Abstract (en)
[origin: WO2015197945A1] The invention concerns a method for encoding a digital image, said image being divided into a plurality of blocks of pixels processed in a defined order, said method comprising the following steps, implemented for a current block: -Predicting (E1) the values of the current block from at least one previously processed block, according to a prediction method chosen from a plurality of possible methods, -Calculating (E2) a residual block by subtracting the predicted values from the original values of the current block, -Obtaining (E3) a transformed residual block by applying a transform to the pixels of the residual block, said residual block comprising coefficients, -Selecting (E7) the signs of the coefficients to predict in the transformed residual block; -Predicting (E9) the selected signs in the current block from encoded neighbouring blocks that have been decoded; -Calculating (E10) a prediction indicator of the selected signs from the predictions of the selected signs and the original values of same, -Carrying out entropy encoding (E11) of the values of indicators obtained for the predicted signs. According to the invention, the method comprises a step of determining a context of a coefficient of the current residual block from a plurality of predefined contexts, and the sign of a coefficient of the transformed residual block is selected depending on a predefined score associated with the encoding context of said coefficient, said score being representative of a reliability level of the prediction of the sign.
IPC 8 full level
H04N 19/50 (2014.01); H04N 19/103 (2014.01); H04N 19/115 (2014.01); H04N 19/132 (2014.01); H04N 19/134 (2014.01); H04N 19/18 (2014.01); H04N 19/463 (2014.01); H04N 19/61 (2014.01)
CPC (source: EP KR US)
H04N 19/103 (2014.11 - EP KR US); H04N 19/115 (2014.11 - EP KR US); H04N 19/132 (2014.11 - EP KR US); H04N 19/134 (2014.11 - EP KR US); H04N 19/154 (2014.11 - EP KR US); H04N 19/18 (2014.11 - EP KR US); H04N 19/463 (2014.11 - EP KR US); H04N 19/50 (2014.11 - EP KR US); H04N 19/61 (2014.11 - EP KR US); H04N 19/91 (2014.11 - US)
Citation (search report)
See references of WO 2015197945A1
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
FR 3023112 A1 20160101; CN 106797472 A 20170531; EP 3183879 A1 20170628; JP 2017521980 A 20170803; KR 20170026536 A 20170308; US 2017142444 A1 20170518; WO 2015197945 A1 20151230
DOCDB simple family (application)
FR 1456032 A 20140627; CN 201580035066 A 20150616; EP 15756178 A 20150616; FR 2015051587 W 20150616; JP 2017520009 A 20150616; KR 20177002499 A 20150616; US 201515322156 A 20150616