Patent ID: 8428132
Filing Date: 2013-04-23
Classification: H04N

Abstract:
1. A method for coding pictures in field or frame mode, the picture frame mode being able to use the field mode locally in the picture, for a group of macroblocks, the method comprising: calculating, for a group of macroblocks in field mode, spatial activities of each constituent macroblock and a temporal activity between the macroblocks of each constituent field, calculating an activity index relating to the group that is an increasing function of the temporal activity and a decreasing function of the calculated spatial activities, comparing the activity index relating to the group, to a predefined threshold, to define it as a group having activity, coding the picture in field or frame mode according to a number of macroblock groups detected having activity with respect to a number of groups of macroblocks in the picture, wherein said group is a supermacroblock and wherein the activity index equals to being an inter-field luminance gradient; being an intra-field luminance gradient in field n; and FY