Image processing program image processing apparatus, an image processing method, and, quantization control program quantization control device, and the quantization control method

摘要

In view of the characteristics of human vision for color, to perform the compression coding of image data. each sub-block of 4 lines × 4 pixels a macroblock is divided, the color of the pixel is detected based on the color difference components Cb, and Cr. Results of the number of pixels that are detected specific color were counted in each sub-block is, for example, at least two-thirds of the total number of pixels of the sub-block, the macro block including the sub-block is to include a specific color. Is modified quantized value preferential activity obtained by using the luminance component Y for this macroblock, corresponding to the specific color are multiplied. Based on this modification activity, the quantization scale value is changed to a smaller value. It is Yeoul the quantization scale value is changed, the degradation in image quality due to the quantization of the macroblock macroblock is quantized with a smaller quantizing step width, the particular color is detected is suppressed.