Multi-purpose watermarking schemes for color halftone image
Kuo-Ming Hung, Ching-Tang Hsieh, Kuan-Ting Yeh · 2006
In many printer and publishing applications, it is desirable to embed data in halftone images for copyright control and authentication purposes. However, the robustness of the geometrical attacks in halftone watermarking is still a key problem. In this paper, we proposed a multipurpose color halftone watermarking using embedding watermark into the pixel with complicated texture by wavelet transform based on the dithering technique in the halftone processing. According to properties of the color model (R,G,B), we chosen the G level for embedded our robust watermark and B level for embedded our semi-fragile watermark. The Zernike moment is adopted to detect rotation and scale of the watermarked image. Experimental results show that watermarked image with good visual quality and the robust watermark is robust to the malicious attacks such as compress, corrupting, cropping, rotating, and scaling. The semi-fragile watermark can detect the regions where attacked by corrupted and cropped.