Method for Changing Chroma Space Sample Structure in Compressed Domain
Jun Sun · Shuju caiji yu chuli · 2004
How to convert 4∶2∶2 MPEG stream into 4∶2∶0 MPEG stream in the compressed domain is discussed. Firstly,the algorithm for accomplishing spatial domain low-pass filtering in the compressed domain is formulated based on the properties of the DCT. In this algorithm,using multiplication of matrix with 8×8 dimensions in the DCT domain implements spatial domain linear filtering. Secondly,after analyzing the reason to produce drift in the processing of conversion,low order filter is chosen for reducing filter processing drift in the compressed domain. Finally,the simulation validates that the approach can produce the reasonable image quality. Although the quality of the chroma picture is degraded a little,the computation complexity is reduced.