WATERMARKING FOR HALFTONED IMAGES USINGERROR DIFFUSION
AhmadMovahedian Attar, Shadrokh Samavi, Rasoul Amirfattahi · 2006
Halftoning istheprocess ofrepresenting a gray-level imagewithabinary image. Imagedatahiding isthehiding of invisible patterns inanimagewithout degrading itsvisual quality. Inthis paperwepropose a methodcalled Error Diffusion withNonlinear Thresholding (EDNT)toembed hidden datainahalftone imagesuchthat thehidden patterns canbevisually inspected whentheimages areoverlaid. The hidden imagecanalsobeextracted bymeansofXNOR operation onwatermarked andoriginal halftone images.