High Capacity and Secure Watermarking for Medical Images Using Tchebichef Moments

Abstract

Using Tchebichef Moments, this study has introduced a new method for imperceptible watermarking of the medical images with a high embedding capacity and robustness against the various attacks. The suggested method applies conditional quantization based on dither modulation to minimize the number of the moment orders that need to be changed. Reduction of modified moments increases the watermark imperceptibility and hence decreases the attacks probability. The proposed method has been examined in the presence of such factors as quantization step and watermark size. Experimental results show that average PSNR is 53.91 dB for 16384 embedding watermark bits. Moreover, the introduced algorithm has been tested for known attacks like scaling, cropping, noise, etc. It has been shown that our proposed method has proper security and robustness against various attacks. In addition, zero false positive rate on non-watermarked images has been obtained.