Forming half tone raster points - de-arranging regularity of arrangement between density values and partial raster spot forms to achieve desired irregularity

摘要

The density values of the scanned original document points falling in lines and columns are assigned to a regular sequence of repeated partial raster spot forms. The density values determine the concrete partial raster point of corresp. form. The regularity of the assignment between density values and partial raster point forms (R11,R12,R22) is disassembled to produce a desired irregularity. The ordering between density values and partial raster point forms can be made by a random generator (21) which assigns an arbitrary partial raster point form from all those available to each density value. The decision for deranging can also be made dependent about a random generator (22). USE/ADVANTAGE - Producing print forme for colour separations avoiding Moire effect achieving better detail contrast.