Patent ID: 8279918
Filing Date: 2012-10-02
Classification: H04N

Abstract:
1. A method for temporal decomposition and reconstruction of an input video signal that uses a prediction process and an update process in framework of motion compensated temporal filtering (MCTF), the motion information used for the update process being derived from the motion information used for the prediction process, the method employing a block based video codec composed of an encoder and a decoder, the method comprising: receiving a residual picture signal having a precision; receiving a low-pass picture signal having a precision that is less than the precision of the residual picture signal; in response to the residual picture signal being decoded in the decoder, clipping the residual picture signal such that the residual picture signal is reduced in precision, such that the low-pass picture signal, a reconstructed picture, and the clipped residual picture signal have equal precisions; performing an inverse MCTF process, comprising a lifting scheme, on the clipped residual picture signal; in response to the block based video codec selecting a block mode for each block, avoiding selecting a block mode in which a residual clipping would lead to breaking a perfect reconstruction property of the MCTF, thereby defining a constrained mode decision, wherein the constrained mode decision considers a mode in accordance with the following: define ĥ d x is a vector describing a position of a pixel in a picture, k describes a temporal position of the picture, ĥ[x,k] describes the residual picture signal, C is a clipping function C(w), ĥ A where B is a block being considered, C′ is clipping function C modified such that A′ {tilde over (h)}[x,k] is an estimation of the signal ĥ[x,k] that will be received at the decoder; and verify if d