Method for touching up scanned binary image data redigitalized in pixels sets aside local scanning/halftone defects caused by dust and scratches by selecting and registering defective halftone dots.

摘要

A binary pattern (1) to be corrected is first picked up. Binary erosion (2) of detected halftone dots is then carried out by means of a Yes/No inquiry (3) run through a loop until the halftone dots have a uniform shading for their halftone cells of less than 35 percent. All possible halftone spots are detected (5) by a Yes/No inquiry and the existing halftone structure is analyzed (4) in order to select defect halftone spots in a selected halftone/image area.