| 摘要 |
PROBLEM TO BE SOLVED: To process an image at a high speed even by the combination processing of the expansion processing and the compression processing and to obtain the reduction result with less deterioration in image quality by conducting the processing combining expansion processing and reduction processing under a specific condition. SOLUTION: A change point coordinate string after reduction in response to a reduction magnification is obtained from change point coordinate strings to white level picture elements and black level picture elements in the main scanning direction of image data. As to a change point coordinate in the obtained change point coordinate string, a distance of each with a just preceding change point coordinate is obtained. Then each change point coordinate of the change point coordinate string is used for a change point coordinate object to a white level picture element when the obtained distance is 1 or over and the change point coordinate is a change point coordinate to the white level picture element, and when the distance is 0, the change point coordinate object to the white level picture element corresponding to the just preceding change point coordinate is invalidated. When the obtained distance is 1 or over and the change point object to the white level picture element is in existence and the change point is a change point coordinate to the black level picture element, the change point coordinate is used for a change point coordinate to the black picture element and the change point coordinate object to the white level picture element is used for the change point coordinate to the white level picture element. |
