Patent ID: 8175153
Filing Date: 2012-05-08
Classification: H04N

Abstract:
1. A method for coding a picture sequence comprising a hierarchical temporal analysis of a group of pictures performing a motion compensated temporal filtering of successive pairs of pictures to supply low temporal frequency pictures and high temporal frequency pictures at different temporal decomposition levels, this analysis realizing, for a given temporal decomposition level and for a pair of low temporal frequency pictures, a motion estimation operation of a current picture B to a previous reference picture A to supply motion vectors then a motion compensated temporal filtering of these pictures to supply a low temporal frequency picture (L) and a high temporal frequency picture (H) at a greater decomposition level, the temporal filtering being replaced by an intra mode coding to obtain at least one low (L) or high (H) frequency picture if the current picture has a level of correlation with a previous picture lower than a threshold, the low frequency pictures (L) obtained being thus scaled to be adapted, at the energy level, to the pictures obtained by the motion compensated temporal filtering, the method comprising, among the low frequency picture and the final high frequency decomposed pictures obtained at the end of the analysis: a selection operation to select the low (L) or high (H) frequency pictures obtained by intra coding of a picture at a lower decomposition level with the additional condition, for the high frequency pictures, that this picture is derived itself from an intra coding, and a calibration operation to calibrate the selected pictures by carrying out at least one reverse operation of the scaling operation, for their coding.