Green-Noise Diffusion Watermark Method enabling to embed Multiple information

Abstract

I propose an invisible digital watermarking which enable to embed two types of information. The main information consists of bit data of the character code representing Green-Noise characteristics, and sub information consists of bi-level pattern of logos and figures representing checkerboard pattern. These patterns are combined with image data on spatial domain. The Green-Noise pattern is difficult to recognize visually and shows robustness against various attacks. The spectrum of sub information is distributed in a higher frequency region which does not overlap with the spectrum of Green-Noise pattern, resulting in a fragile watermark. These two types’ watermarks can be extracted by different watermark extractors. It can be applied to protection of copyright protection, detection of tampered position, tracking of illegal outflow etc. Further, the sub information can be used as a synchronization signal for extracting the watermark of the main information or as a copy-forgery-inhibited pattern for printing.