Depth Perception Based Multi-Purpose Stereo Image Watermarking Method

To authenticate and protect stereo image simultaneously, this paper proposes a depth perception based multipurpose stereo image watermarking method for three dimensional television systems. The proposed method embeds semi-fragile and robust watermark for different purpose. In order to assure quality of watermarked stereo images, binocular perception is used to divide stereo image into region of interest (ROI) and non-ROI for embedding semi-fragile and robust watermark, respectively. Parity check of quantization value of discrete cosine transform coefficients is used to embed watermark, and different quantization step values are employed for ROI and non-ROI. Moreover, the quantization step value is determined by using just noticeable difference and an adjusted value for ROI. Experimental results demonstrate that it not only can distinguish common image processing from malicious attack, but also can claim copyright of stereo image under many kinds of attacks, such as JPEG compression, filter, salt and pepper, and so on. Keywords—three dimensional television system; stereo image; multi-purpose watermarking; copyright protection