An Adaptive Watermarking Technique for Digital Colored Images

In this research, an algorithm for colored digital image watermarking is proposed. The 24 bits/pixel RGB images are converted to the YIQ color model which is used in NTSC TV system, and the watermark is placed on the Y part of the resulting image after scrambling it using pseudo-random permutation. Also, insertion of the watermark bits on the host image blocks is done in a pseudo-random fashion. The algorithm takes into account the human visual system. This algorithm gets more than 70 dB of average PSNR for all used images and watermarks which satisfy the PSNR bench mark. Also it gets about 0.09 of MAE, the robustness measure, which means that it is very robust after testing it using the following attacks: low pass filtering, median filtering, scaling, cropping, rotation, JPEG 100, JPEG 75, JPEG 50 and JPEG 25