Generic Lossless Visible Watermarking

For generic visible watermarking with a capability of lossless image recovery, a novel method is proposed. This method is based on the deterministic one-to-one compound mappings of image pixel values for covering a variety of visible watermarks of arbitrary sizes on the host images. The compound mappings are proved to be reversible, that means it allows lossless recovery of original images from watermarked images, so that recovered image and the host image should be the same. The mappings may be adjusted to yield pixel values close to those of desired visible watermarks. Including opaque monochrome and translucent full color ones, different types of visible watermarks are embedded as applications of the proposed generic approach. To produce more distinctive visible watermarks in the watermarked image, a two-fold monotonically increasing compound mapping is created and proved. Security protection measures by parameter and mapping randomizations and also by using the HASH algorithm have also been proposed to prevent attackers from illegitimate image recoveries. Experimental results representing the convenience of the proposed approach are also included.