| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform rate control for sustaining good subjective image quality without using nonlinear quantization of frequency coefficient in an encoder or a parser (transcoder) of JPEG2000, or the like. <P>SOLUTION: In an encoder of JPEG2000, calculation of distortion slope for MQ encoding and rate control is performed at processing block 103, and rate control is performed by discarding MQ code (truncation) at processing block 104. When distortion slope is calculated at the processing block 103, a monotone decreasing function is introduced and such a distortion slope as lowering the significance of a code of high order bit plane relatively is employed so that truncation amount of a code block including a coefficient of large absolute value is increased but truncation amount of other code block is decreased thus attaining rate control of good subjective image quality. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
