| 摘要 |
The invention relates to a method for digitally rasterizing a half-tone image with rasters of any width and angle. According to the invention, a threshold matrix is read out and the threshold values are compared with the colour values of the half-tone image. The threshold matrix used is a threshold matrix in which the threshold values represent one or several pixels of a raster, said raster being arranged at an angle and being used to approximate the desired raster width and the desired raster angle. Whilst the threshold values are being read out, an error between the desired raster and the raster approximated using the threshold matrix is detected and as soon as said error exceeds a predetermined limit value, said error is compensated by a correction of the readout address for the threshold matrix. Stored bit patterns can also be used as an alternative to the threshold matrix. Said bit patterns can be obtained by comparing the tone values which have to be reproduced and a threshold matrix. |
