Matsushita Graphic Communication Systems, Inc.

Panasonic Communications Co., Ltd.

Fumiko Koshimizu

Shinichi Sato

Yoshikazu Naito

Error addition section generates correction data by adding correction value Emo and correction value E to the input data. Binary processing section converts the correction data to binary data to generate output data. Binary error calculation section calculates binary error E based on the correction data and output data. Propagation coefficient judgment section judges propagation coefficients K to K Propagation error operation section operates on binary error E and propagation coefficients K to K to calculate correction value E and correction value Emi. Error memory temporarily stores correction value Emi, and outputs it to error addition section when the pixel data to be corrected is input.

Image processor for processing an image with an error diffusion process and image processing method for processing an image with an error diffusion process

The image scaling processing device distinguishes whether an original image data is a character image or a half-tone image per a pixel unit in the image domain separating portion and scales each image in the character scaling processing portion and the half-tone scaling processing portion. In order to get a desired scale factor L times image data, the character scaling processing is performed by the first scaling processing for enlarging an image data by 2.sup.n times (n is an integer, L&lt;2.sup.n) in each sub scanning direction and main scanning direction and by the second scaling processing for reducing by L/2.sup.n times the image data enlarged by 2.sup.n times and the half-tone scaling processing is made by the first scaling processing for enlarging an image data by 2.sup.n times (n is an integer, L&gt;2.sup.n) in each sub scanning direction and main scanning direction and by the second scaling processing for enlarging by L/2.sup.n times the image data enlarged by 2.sup.n times.

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Machida, Japan

Fumiko Koshimizu