Method and apparatus for generating halftone images having human readable patterns formed therein

Abstract

An apparatus and method for producing a halftone image generates halftone cells based on grayscale image data and bitmap code. A human readable pattern is embedded within the halftone image. Each of the halftone cells is formed from dot patterns having one of a plurality of predetermined shapes. The predetermined shapes of the halftone cells form the human readable pattern. The halftone cells are written onto a recording medium to produce the halftone image. Rotation of the halftone cells allows data to be encoded within each of the halftone cells without varying the tone of the image. The tone of the image may be controlled by selectively varying a thickness of the dot patterns within the halftone cells.

Dependencies are inferred from the claim text.