| 摘要 |
<p>The present invention relates to a method to binarize multivalued image with variable density. As the method for binarization, ordered dither method and error diffusion method are known, whereas satisfactory reproduction of the image is not always achieved in case of color image. According to this invention, input signal from the input pixel is binarized by threshold. The error between the input signal and the threshold is divided at the predetermined coefficient ratio and is accumulated and added to input signal from the subsequent input pixels, and the predetermined ratio is determined in proportion to the coefficient of the element of partical matrix fixedly corresponding to the input value matrix. By performing this procedure on all pixels of the color image through scanning, binary value image of monochromatic image of the color image can be obtained. In case the monochromatic image to be superimposed is reproduced for each color, coefficient matrix is rotated at different angle for each color, and the above processing is performed. <IMAGE></p> |
