HP Labs Technical Reports

Watermarking of Dither Halftoned Images

Baharav, Zachi; Shaked, Doron

HPL-98-32

Keyword(s): watermarking; halftoned printing; printing security; dithering

Abstract: This report concerns embedding of watermarks into dither halftoning. The basic idea is to use a sequence of two dither matrices (instead of one) to encode the watermark. Assuming a specific distribution of the input image leads to an optimal decoding algorithm, and an optimal dither matrix pair matching. Finally, an example is given, which demonstrates the ideas. The example is synthetic in the sense that it does not use printing and re-scanning of the image.

14 Pages

Back to Index