IMAGE SIGNAL BAND COMPRESSION SYSTEM

摘要

PURPOSE:To enable the selection of the mode of some kind to be prohibited or forced by permuting the value of the interpolation error of each mode for a value which is previously fixed when the mode of each block is decided. CONSTITUTION:For an image signal 50 inputted from an input terminal, the thinning and the interpolation of the mode 2 are executed by a mode 2 thinning and interpolation circuit 1, the output of it is inputted to a difference circuit 2 and the difference between an interpolation signal and an original signal is calculated. The difference signal of it is inputted to an interpolation error calculation circuit 3. Then, a total sum S in the block of the absolute value of the difference signal is calculated and outputted as an interpolation error signal 51. The signal 51 and a permutation decision signal 52 are inputted to an interpolation error permutation circuit 4 and one part or the whole part of the signal 51 is permuted according to the signal 52. This permuted interpolation error signal 56 is outputted to a histogram producing circuit 6. In a mode decision circuit 7, the mode for the whole block is decided by using the permuted signal 56 and a threshold(Th).