Calculation of Peak Signal-to-Noise Ratio (PSNR) for Two Images with Normalization Coefficients and DWT-Based Digital Watermark Embedding

In the digital watermark embedding process, we evaluate the quality of embedded watermarks by calculating the Peak Signal-to-Noise Ratio (PSNR) between two images. The PSNR calculation formula involves computing normalization coefficients and applying Discrete Wavelet Transform (DWT). Through these computational processes and applications, we can effectively embed digital watermarks while maintaining image quality and providing data protection and authentication capabilities. Key implementation aspects include: - PSNR calculation using mean squared error (MSE) between original and watermarked images - Normalization coefficient determination based on image pixel value ranges - Multi-level DWT decomposition for selecting optimal embedding frequency bands - Watermark embedding through coefficient modification in transform domain - Inverse DWT reconstruction to generate watermarked images - Quality verification through PSNR measurement and visual assessment The algorithm typically involves MATLAB functions like dwt2() for wavelet decomposition, idwt2() for reconstruction, and immse() for mean square error calculation, followed by PSNR computation using 20*log10(MAX_I/sqrt(MSE)) where MAX_I represents the maximum possible pixel value.