Adaptive piecewise linear bits estimation model for MPEG based video coding

We propose an adaptive piecewise linear bits estimation model whose structure is similar to a tree-structured piecewise linear filter. Each node in the tree is associated with a linear relationship between macroblock bits and activity/stepsize. The parameters in this tree structure are adjusted by a modified LMS algorithm. Computer simulation results indicate that the adaptive bits model is able to precisely estimate the compressed bits regardless how the image contents vary along time. Also, when compared to the table-look-up bits model derived based on cluster analysis, the adaptive piecewise linear bits model has a much lower complexity to achieve about the same high performance