| 摘要 |
PURPOSE:To reduce quantization enthrophy, to improve the quality of an image, and to decrease the number of necessary transmission bits by allocating a code to a block in which quantization representative values obtained from an encoded picture element and a picture element to be encoded are included corresponding to the generation probability, or allocating a code by properly switching. CONSTITUTION:Before a transmission signal encoding part 29, a blocking part 30 to generate a block of the quantization representative values of several picture elements is provided. Assuming the quantization representative value of a block consisting of quantization values by two pieces of picture elements is eight, 8<2> of codes are necessary. A noise shaping filter allocates long and short codes to the combinations of quantization representative values corresponding to the magnitude of generation probablity by using the variation characteristic of proper quantization representative values, hence the number of encoding bits necessary for the transmission of the representative values can be reduced. Or, by using a successive adaptive coding part 31 instead of encoding part 29, a code to be allocated to the representative value of a subsequent picture element is determined out of the quantization representative value of the immediately preceeding preliminarily encoded picture element, and thus the number of encoding bits is decreased. |
