A visible digital watermarking system using perceptual models

This paper presents a visible watermarking system using perceptual models. A watermark image is overlaid translucently onto a primary image, for the purposes of immediate claim of copyright, instantaneous recognition of owner or creator, or deterrence to piracy of digital images or video. The watermark is modulated by exploiting combined DCT-domain and DWT-domain perceptual models. The resulting watermarked image is visually pleasing and unobtrusive. The location, size and strength of the watermark vary randomly with the underlying image. The randomization makes the automatic removal of the watermark difficult even though the algorithm is known publicly but the key to the random sequence generator. The experiments demonstrate that the watermarked images have pleasant visual effect and strong robustness. The watermarking system can be used in copyright notification and protection.