| 摘要 |
<p>PURPOSE:To attain a large compression rate by applying preprocessing decreasing a high spatial frequency component and applying post-processing emphasizing the high spatial frequency component so as to keep the required picture quality. CONSTITUTION:The pre-processing decreasing the high spatial frequency component is executed prior to redundancy suppression coding processing in the compression process. As a result, the compression rate by the redundancy suppression coding processing is improved. In decreasing the high spatial frequency component in this way, the image is blurred in reproduced image and the picture quality is deteriorated, but the high spatial frequency component emphasis post-processing corresponding to the high spatial frequency component reduction pre-processing in the compression processing is executed in the expansion processing so as to decrease the deterioration in the picture quality and a satisfactory reproduced image is obtained.</p> |
