IMAGE ENCODING METHOD

摘要

PROBLEM TO BE SOLVED: To transfer an image signal without lowering picture quality even through a signal line such as a telephone line having a low bit band. SOLUTION: An image signal in a picture element S(1) is approximated by an approximate plane constituted by using image signalsα1 ,α2 ,α3 andα4 at respective apexes P1 (1, 1), P2 (a, 1), P3 (1, b) and P4 (a, b). The approximate value of an image signal at any arbitrary point q(u, v) becomesϕ. The residual between this approximate value and the value of a real image signal is found and a feature amount showing more or less features of image at the picture element S(1) is found from the residual. According to the found feature amount, a code amount of be used for encoding is controlled.