Picture encoding apparatus, picture encoding method, picture encoding and transmitting method, and picture record medium

摘要

On a decoding side, parameters (minimum value MIN and dynamic range DR) are optimized in such a manner that a decoded error of original signal values and restored values becomes minimum. A maximum value detecting portion 2 detects the maximum value MAX of pixels of each block composed of (3x3) pixels. Likewise, a minimum value detecting portion 3 detects the minimum value MIN. A subtracting portion 4 generates a dynamic range DR. A subtracting portion 5 subtracts MIN from each of input pixel values y and generates normalized values. A step width calculating portion 6 calculates a quantizing step width DELTA with DR. A quantizing portion 7 generates quantized values x (each of which is composed of 4 bits) with DELTA . A least squares method based estimating portion 8 generates decoded values y' with y and x and obtains an optimized dynamic range DR' and an optimized minimum value MIN' in such a manner that the sum of square of an error (y'-y) becomes minimum. A framing portion 11 frames x, DR', and MIN' and records the framed data on a record medium 15 through an error-correction-code adding portion 12, a modulating portion 13, and a recording portion 14.