Unseen Visible Watermarking for Gray Level Images Based on Gamma Correction

Abstract

In this paper, we proposed a novel watermarking technology with the properties that from visible watermarking and invisible watermarking. In the common situation our approach can he used to transmit the multimedia files, according to the gamma correction. the watermark can be revealed. Our proposed method has a unique feature that we can obtain a watermarked-image similar to the original image after embedding watermarks. The naked eye hardly realized the watermarks, but after adjusting the viewing angle, it then demonstrated the embedded watermarks. We embed the unseen visible watermarks by adjusting degree of saturation and value of HSV model in the color space. The experiment result shows that the PSNR values of the watermarked images are more than 45 dB, sometimes even as high as 55 dB.