Patent ID: 6728316
Filing Date: 2004-04-27
Classification: H04N

Abstract:
A video coding method applied to a sequence of frames and based on a three-dimensional (3D) decomposition with motion estimation and compensation on couples of frames, said decomposition being a wavelet transform that leads from the original set of picture elements (pixels) of the frames to transform coefficients constituting a hierarchical pyramid, and a spatio-temporal orientation treeâ€”in which the roots are formed with the pixels of the approximation subband resulting from the 3D wavelet transform and the offspring of each of these pixels is formed with the pixels of the higher sub-bands corresponding to the image volume defined by these root pixelsâ€”defining the spatio-temporal relationship inside said hierarchical pyramid, said method being characterized in that, for obtaining an encoded bitstream scalable in SNR (signal-to-noise ratio), spatial and temporal resolutions, it comprises the steps of:(A) organizing the transform coefficients of said tree in a structure of 3D macroblocks, separated by resolution flags respectively associated to the beginning of each macroblock, and blocks, the size of each block fitting the lowest approximation sub-band which contains all the transform coefficients at the coarsest resolution, and all the blocks within each 3D macroblock being themselves organized in successive two-dimensional (2D) macroblocks belonging to a specific spatial decomposition level and grouped for all the frames of a specific temporal decomposition level; (B) scanning the coefficients of each 3D macroblock in a predetermined order defined, inside each block, by the spatial orientation of said block and, inside a 3D macroblock, by an association of blocks having the same location in all the frames of a temporal decomposition level; (C) encoding said scanned coefficients bitplane by bitplane.