Patent ID: 7792193
Filing Date: 2010-09-07
Classification: H04N

Abstract:
1. An image encoding method for encoding an image signal according to an encoding mode, comprising: generating a predictive signal and encoding mode information according to each of a plurality of encoding modes from a macroblock signal corresponding to each macroblock of a plurality of macroblocks generated by dividing an input image signal; selecting a quantization code table corresponding to each macroblock from a plurality of quantization code tables; generating a predictive error signal for each of the encoding modes based on the macroblock signal and the predictive signal; subjecting the predictive error signal to orthogonal transformation; quantizing the orthogonal-transformed predictive error signal while changing a quantization parameter for every plural sub-pixel-blocks in the macroblock, using the quantization code table corresponding to the macroblock to generate a quantization transformation coefficient; encoding the quantization transformation coefficient; calculating an encoding cost from encoding distortion and number of encoded bits of the encoded quantization transformation coefficient; selecting one encoding mode from the encoding modes based on the encoding cost; selecting one quantization code table from the quantization code tables based on the encoding cost; and encoding information of an index indicating the selected quantization code table for every encoding part of the input image signal, the encoding part including one of a frame of the input image signal and a region of the frame.