| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique that enables more minute image quality adjustment and code amount adjustment at a transcoder that decodes an input image into a decoded image and encodes the decoded image into an output image.SOLUTION: A quantization step value determination part 6 determines an output quantization step value for each macro block by correcting an input quantization step value based on various characteristic evaluation values. A CPU 5 controls the quantization step value determination part 6 in accordance with an input/output state based on an input bit rate, an output bit rate, and a target bit rate. The transcoder 1 is capable of performing image quality adjustment and code amount adjustment more minutely. As the various characteristic evaluation values, it is possible to cite an evaluation value indicative of a change degree in a space direction, an evaluation value indicative of a change degree in a time direction, an evaluation value indicative of a prediction error in the time direction, an evaluation value indicative of skin color chromaticity, and an evaluation value indicative of a coordinate position of each macro block. |
