PURPOSE: To surely attain up-dating of a code book by providing a memory storing one of patterns generated at the same time.
CONSTITUTION: A picture data of one pattern obtained by adding an average data and a difference data of two patterns is obtained through an adder 51 and inputted directly to a selector 72. Similarly, a picture data of the 2nd pattern obtained by subtracting the difference data from the average data of the two patterns is obtained through a subtractor 52 and the data is stored once in a memory 6. A selector 72 selects the input from the adder 51 on the display of the 1st pattern and sends it to an interpolation filter 71. The selector 72 selects the picture data of the 2nd pattern stored in the memory 6 and sends it to the filter 71. Code book RAMs 21, 22 are not used for the coding during this period and only the quantity required to decode the succeeding picture pair is up-dated.
YASUOKA MASAHIRO
KAWAI SATOSHI
HITACHI VIDEO ENG