| 摘要 |
<p>PURPOSE:To suggest a more effective conversion pattern and to increase the density of a binary image by means of a simple logic calculation without using a pattern memory and to perform the interpolation of the binary image when the binary image is improved in density and interpolated. CONSTITUTION:A single original picture element is divided into 2<n> (n: integer) in a main scanning direction or into 2 (m: integer) in a subscanning direction, and the concentration value of the subdivided picture element of the divided original picture element is determined by a concentration value determination circuit 230 based on the concentration value of the original picture element and the concentration value of the surrounding picture elements. The tilting angle of shading lines subject to the interpolation processing is detected, the number of subdivided picture elements reversing the concentration for the interpolation processing is changed in accordance with the tilting angle, the width of the shading line subject to the interpolation processing is detected, and the concentration inverting operation for the interpolation processing is controlled corresponding to the width of the tilt. Thus, the image can be obtained in which the profile of a character image is smoothened with improved effectiveness without missing any black line.</p> |
