Patent AU-2022201084-B2 (AU)
Title: Image predict coding method, image predict coding device, image predict coding program, image predict decoding method, image predict decoding device, and image predict decoding program
Inventor: BOON CHOONG SENG
IPC: H04N19/91
Filed: 2022-02-18
Granted: 2023-02-16
Abstract: IMAGE PREDICT CODING METHOD, IMAGE PREDICT CODING DEVICE, IMAGE 
PREDICT CODING PROGRAM, IMAGE PREDICT DECODING METHOD, IMAGE 
PREDICT DECODING DEVICE, AND IMAGE PREDICT DECODING PROGRAM 
ABSTRACT 
An image predictive decoding device and an image predictive decoding method a disclosed In one aspect, the image 
poedictive decoding device comprises: input means for accepting input of compessed pictum data and encoded 
infonration, the compressed pictum data containing a residual signal generated by dividing a pictum into a plurality of 
blocks and performing predictive encoding of a target block, and the encoded information about a prediction mode 
indicative of a generation method of a podicted signal of the target block;, storation means for extrcting the rsidual 
signal of the target block frm the compressed pictu data to estoe a oepduced residual signal; pdiction mode 
decoding means for storing the encoded information about the prediction mode to generate a prediction mode; 
predicted signal generation means for generating the predicted signal of the target block based on the prediction mode; 
pictum restoration means for adding the predicted signal to the opomduced residual signal to estoe a pixel signal ofthe 
target block; and storage means for storing the estoed pixel signal as a produced pixel signal whemein the prediction 
mode decoding means generates a candidate pedictionmode list by adding, as elements, pedictionmodes ofa plurlity 
ofpoeviously-oproduced blocks neighboring the target block, the candidate prediction mode list containing no duplicate 
poedictionmodes as the elements, whemein the pedictionmode decoding means decodes a flag that indicates whether or 
not the candidate pedictionmode list contains an element conesponding to the pedictionmode; when the flag indicates 
that the conesponding element is psent in the candidate prediction mode list, the prediction mode decoding means 
further decodes an index indexing the candidate prediction mode list to obtain an element indicated by the index as the 
prediction mode; when the flag indicates that no consponding element is posent in the candidate prediction mode list, 
the prediction mode decoding means father decodes a value of a REM remaining ) mode to esto the value of the 
REM mode as a numerical value of a fixed-length code; sets a variable for the intra-firme prediction mode ofthe target 
block equal to a decided value ofthe REM mode;, peatedly performs a found of comparison between the variable and 
one of elements on the candidate prdiction list that stats from a smallest element on the candidate list in an initial round 
of comparison and moves in a next iound of comparison to a next larger element on the candidate list until aching a 
highest element thereon, and in every round of comparison, incoementing a value of the variable for use of the 
incoemented value ofthe variable in anextiound of comparison when the variable is larger than or equalto the one ofthe 
elements, whemeas keeping the value ofthe variable unchanged for use ofthe unchanged value of the variable in a next 
round of comparison when the variable is smaller than the one ofthe elements; and uses a final value ofthe variable as a 
poedictionmode for decoding thetargetblock.