VERBESSERTES VERFAHREN ZUR FREQUENZMODULIERTEN HALBTONRASTERUNG

The present invention provides a method for screening a continuous tone image comprising the steps of: selecting an unprocessed image pixel according to a randomized space filling two-dimensional curve and processing said unprocessed image pixel as follows: determining from the tone value of said unprocessed image pixel a reproduction value to be used for recording said image pixel on a recording medium, calculating an error value on the basis of the difference between said tone value of said unprocessed image pixel and said reproduction value, said unprocessed image pixel thereby becoming a processed image pixel, adding said error value to the tone value of an unprocessed image pixel and replacing said tone value with the resulting sum or alternatively distributing said error value over two or more unprocessed image pixels by replacing the tone value of each of said unprocessed image pixels to which said error value will be distributed by the sum of the tone value of the unprocessed image pixel and part of said error, repeating the above steps until all image pixels are processed.