METHOD FOR ENCODING AND DECODING IMAGES, DEVICE FOR ENCODING AND DECODING IMAGES AND CORRESPONDING COMPUTER PROGRAMS

摘要

A method is providing for encoding at least one image cut into blocks. The method implements, for a current block to be encoded, acts of: predicting the current block in accordance with a prediction mode selected among predetermined prediction modes; obtaining a predictor block; determining a residual data set, representative of the difference between the predictor block obtained and the current block, the residual data being likely to have an amplitude and a sign; selecting, from the residual data set, a piece of residual data assigned an amplitude and a sign, using a predetermined criterion which is a function of the selected prediction mode; obtaining a predicted value of the sign of the selected piece of residual data; calculating information representing the difference between the predicted value of the sign and the value of the sign of the selected piece of residual data; and encoding the calculated information.

主权项

1. A coding method for coding at least one image subdivided into blocks, implementing, for a current block to be coded, the following acts performed by a coding device:
predicting the current block in accordance with a prediction mode selected from a plurality of predetermined prediction modes, obtaining a predictor block, determining a set of residual data representative of a difference between the predictor block obtained and the current block, said residual data being likely to have an amplitude and a sign, selecting, from said set of residual data, at least one residual datum assigned an amplitude and a sign, using a predetermined criterion which is a function of the selected prediction mode, obtaining a predicted value of the sign of said at least one selected residual datum, computing an information item representative of the difference between the predicted value of said sign and the value of the sign of said at least one selected residual datum, and coding said computed information item.