image processing with rauschanreicherungsoperatoren for moire - reduction and / or zufallspunkterzeugung

摘要

In an image processing device for processing image data representing an image, and including an image filtering arrangement (22), a filter function is applied to the image data (10-20) that greatly amplifies or enhances high frequency image data, including noise inherent in the image. Such noise, which may be the granularity of the image, when enhanced, serves to mask the beating pattern of moiré. One function which accomplishes adequate high frequency and noise filtering is a modified Laplacian function with a maximum modulation at a frequency of the noise or granularity of the image. Similarly, the special effect of a random screen image or mezzo tint is obtained when a continuous tone image is processed with the modified Laplacian filtering function, and subsequently thresholded in a thresholding arrangement (28).