| 摘要 |
PURPOSE:To realize a variable power processing in which the picture quality of a binary and multi-value mixing image is not reduced by calculating the gradation of an picture element inserted from the gradation of the adjoining picture element and executing the variaible power processing concerning the area of a halftone image and executing the variable power processing of the same binary image as the conventional one concerning other areas. CONSTITUTION:First, a variable power area is divided into a halftone image data area (slanting line part) and a binary image data area (white part). For dividing the data area, the information of the halftone image data area is used. For that reason, as the information of the halftone image, a flag to instruct that the halftone image is obtained and the information to show the area are prepared beforehand and stored and held to a main memory 8. Concerning the data area of the binary image, the variable power processing by the same regular sampling method as the conventional one is executed. Thereafter, concerning the halftone image data area, one picture element is divided, for example, into 8 X 8 (dots), the gradation of respective picture elements is obtained and the gradation information is stored into the memory 8. Finally, the gradation of the picture element inserted for expanding is calculated by a proximity picture element substitution negihbourhood average method and the variable power processing is performed by the gradation. |
