DITHER MATRIX METHOD FOR FACSIMILE TELEGRAPH

摘要

The half tone image is expressed finely by adjusting each weighting factor of the dither matrix, which uses the average brightness and the standard deviation of the input image. The method comprises: (a) transfering the M x N image data stored in the signal processor to the first buffer; (b) inputting the weighting factors of K x K dither matrix and storing them to the second buffer; (c) calculating the average brightness and the standard deviation of all input image data pixel and storing them to the first and second registers; (d) converting the weighting factors stored in the buffers with the equation (1); and (e) expressing the half tone image by comparing the converted weighting factor with the M x N image data while shifting the K x K dither matrix.