ENCODER AND ENCODING METHOD

摘要

PROBLEM TO BE SOLVED: To make it possible to suppress the reduction of an SN ratio even when a deviated value exists in a block to be encoded. SOLUTION: An original signal cosisting of 4×4 blocks supplied through an input terminal 21 is supplied to a rearrangement circuit 22. The circuit 22 rearranges respective signal values in the descending order. A MAX' detection circuit 23 calculates a mean value of the prescribed number of signal values from MAX and sets up the calculated mean value as MAX'. A MIN' detection circuit 24 similarly calculates a mean value of the prescribed number of signal values from MIN and sets up the calculated mean value as MIN'. A subtractor 25 generates a dynamic range DR'. A subtractor 27 normalizes each signal value. A quatization circuit 28 quantizes each normalized signal value and generates requantized data Q.