PICTURE SIGNAL CODING AND DECODING METHOD AND RECORDING MEDIUM

摘要

PURPOSE:To improve the coding efficiency by forming a code representing the existence of a non-null conversion coefficient for a color difference signal block separately from a CBP code of the color difference signal block and applying variable length coding to the code together with the CBP code of a luminance signal block. CONSTITUTION:A hybrid coder 12 executes hybrid coding in combination with motion compensation prediction coding and transformation coding such as DCT. A motion compensation prediction error signal S2 of an MB layer outputted from the hybrid coder 12 is subject to variable length coding such as a Huffman code at a VLC device (variable length coder) 13. In this case, the variable length code called the CBP representing whether or not a block in the MB has a non-null DCT coefficient to be sent is added to a header of the MB layer and the resulting code is sent. The CBP is sent so long as any block in the MB has a non-null coefficient. The CBP is formed by a CBP forming device 16 receiving an input of the motion prediction error signal S2.