A DWT- based evaluation method of imperceptibility of watermark in watermarked color image

摘要

The imperceptibility of watermark is one of the most important measures that evaluate the performance of the watermarking algorithm. The conventional evaluation model of image quality, PSNR, can’t evaluate the watermarked image quality well. The masking of background brightness, texture, frequency and color to human vision of color image is analyzed, and then a DWT-based vision masking calculation method of color image is proposed. Based on this method, the vision quality weight of pixel of color image is computed and an evaluation method of color image quality is derived, which is written as MPSNR. The experimental results show MPSNR works better than conventional model PSNR and its evaluation result is consistent with the human visual sensation, which can be used to evaluate the imperceptibility of watermarking algorithm.