| 摘要 |
PURPOSE:To prevent the deterioration of the picture quality of reduced data by initially converting dither picture data to be reduced to estimated multivalued picture data, thereafter, neglecting a picture element to be thinned out and executing a dither processing again. CONSTITUTION:In case of reducing, initially, the dither picture data (original picture) is read from a memory 5 to supply to a binary/multivalue converting part 6 and convert to the estimated multivalued picture data. Namely, the estimated multivalued picture data (g) is inputted to a dither processing part 3 through a sector 2 and made dither again herein. In this case, at the time of an operation, a reduction ratio designating signal (j) is inputted to a thinning out circuit part 7, a reduction ratio designating signal (k) is inputted to the dither processing part 3 from the thinning out circuit part 7 and the dither processing part 3 executes a dither processing including a thinning out according to this signal (k). Thereby, the interference phenomenon of the periodicity of the thinning out and the periodicity of the dither processing is not generated to reduce the deterioration in the picture quality. |
