IMAGE CODER, IMAGE CODING METHOD, IMAGE CODING/ TRANSMISSION METHOD AND IMAGE RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To optimize a parameter (minimum value (MIN) and dynamic range (DR)) at the decoder side so that the decoding error between an original signal and a decoded value becomes small. SOLUTION: A maximum value detection section 2 detects a maximum value (MAX) of a (3×3) blocks, a minimum value detection section 3 detects a minimum value (MIN). A subtractor 4 generates a dynamic range (DR), a subtractor section 5 subtracts the MIN from an input picture element value (y) and normalized. A step width calculation section 6 calculates a quantity step width Δfrom the DR and a quantization section 7 uses the width Δ to generate a 4-bit quantization value (x). A least square estimate section 8 generates a decoded value y' from the values x, y, to obtain an optimum dynamic range (DR') minimizing the square sum of the error (y'-y) and the optimum minimum value (MIN'). A framing section 11 applies framing processing to the x, DR', MIN' and the result is recorded in a recording medium 15 via an error correction code addition section 12, a modulation section 13 and a recording section 14.