| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problem that, in the case where bit depth is different between a luminance signal and a color difference signal and further a value of a luminance quantization parameter is approximate to a lower limit value, a range of values that a color difference quantization parameter may take becomes extremely narrow and any trouble may occasionally occurs in image quality control of the color difference signal.SOLUTION: A luminance signal of an image and a color difference signal having bit depth different from that of the luminance signal are inputted. A luminance quantization parameter to be used for quantizing the inputted luminance signal for the unit of a block is generated. A color difference quantization parameter to be used for quantizing the inputted color difference signal for the unit of a block is generated within a range determined by the luminance quantization parameter. The inputted luminance signal is quantized in accordance with the luminance quantization parameter, and the color difference signal is quantized in accordance with the color difference quantization parameter. In generating the color difference quantization parameter, the range is changed in accordance with the difference of the bit depth between the luminance signal and the color difference signal.</p> |
