Watermark algorithm for color image authentication and restoration

An authentication watermark algorithm for color image tampered region detection and recovery is proposed in this paper. The watermark is generated by the host image, and it is embedded in the 7^th and 8^th bit planes of the host image. During authentication process, rough judgment step and accurate judgment step are performed in series, thus marks the tampered region correctly. The tampered regions may be restored by the regions not tampered. Experimental results show that proposed method has good invisibility, and is suitable for accurate authentication and recovery based applications.