Patent ID: 7986459

Claim:
A grating image for depicting at least one unscreened halftone image having multiple brightness levels, wherein the grating image exhibits, by avoiding any screening, multiple areal, irregularly edged grating fields that include in each case an electromagnetic-radiation-influencing grating pattern composed of a plurality of grating lines and that, when illuminated, produce in each case an areal region of the halftone image having the same brightness level, the grating fields at least partially include grating patterns that are defined by a grating constant and an angular orientation, and/or at least partially include grating patterns that form a matte pattern that displays no diffractive effects when viewed, and the grating fields having grating patterns defined by a grating constant and an angular orientation are filled with the respective grating patterns in an areal fraction that corresponds to the brightness level produced, wherein the grating fields exhibit, corresponding to the brightness level produced, nested regions that are filled with grating patterns and regions that are unfilled, and the grating fields that form a matte pattern are filled, in a density that corresponds to the brightness level produced, with grating lines.