An Image Quality Evaluation Method Based on Digital Watermarking

As a practical and novel application of watermarking, this paper presents a digital watermarking-based image quality evaluation method that can accurately estimate image quality in terms of the classical objective metrics, such as peak signal-to-noise ratio (PSNR), weighted PSNR (wPSNR), and Watson just noticeable difference (JND), without the need for the original image. In this method, a watermark is embedded into the discrete wavelet transform (DWT) domain of the original image using a quantization method. Considering that different images have different frequency distributions, the vulnerability of the watermark for the image is adjusted using automatic control. After the auto-adjustment, the degradation of the extracted watermark can be used to estimate image quality in terms of the classical metrics with high accuracy. We calculated PSNR, wPSNR, and Watson JND quality measures for JPEG compressed images and compared the values with those estimated using the watermarking-based approach. We found that the calculated and estimated measures of quality to be highly correlated, suggesting that the proposed method can provide accurate measures of image quality under JPEG compression. Furthermore, given the similarity between JPEG and MPEG-2, this achievement has paved the road for the practical and accurate quality evaluation of MPEG-2 compressed video. We believe that this achievement is of great importance to video broadcasting