Spatio-temporal segmentation of image sequences for object-oriented low bit-rate image coding
A method for coding of video sequences based on semantic decomposition into motion homogeneous regions is presented. The set of regions-the spatio-temporal segmentation-is intitialized for the first couple of frames of the sequence and then, tracked along the time axis, that allows to maintain its stability. Based on the spatio-temporal segmentation a predictive coding scheme is developed. Motion parameter vector and boundary description are encoded for each spatio temporal region. The bit-rate obtained for motion parameters is very low (<0.01 bits/pixel). The bit-rate for the boundary description strongly depends on the stability of the segmentation and varies around 0.1 bits/pixel. A costless transmission mode is choosen to encode the boundary component. The high visual quality of predicted frames with almost absolute absence of artifacts and a specific structure of prediction error allows the use of a selective coding of error signal.