Method of reconstructing a gray level image from a dithered image.

摘要

A method of calculating the gray scale value for each pixel (3) of a dithered image by counting the number of black pixels within an integration area (1). The integration area (1) is a closed area containing the same number of pixels as the number of different threshold values in the dither matrix that was used to obtain the dithered image. The percentage of black pixels within the integration area (1) gives the gray scale value (3'), which is assigned to the pixel (3) in or near the centre of the integration area (1). The gray scale value (4') of the next pixel (4) is calculated from the number of black pixels within an integration area (2) that is moved one pixel position.