Digital Watermark Processing System Based on DCT Watermarking Algorithm
A DCT-based watermarking algorithm digital watermark processing system primarily consists of two processes: watermark embedding and watermark detection. The watermark embedding process combines the digital watermark (X), original image (I), and key/public key (K) through a digital watermark embedding algorithm to generate the watermarked image (I*). The watermark detection process uses the digital watermark (X), watermarked image (I*), and key/public key (K) through a digital watermark detection algorithm to detect the presence or absence of the watermark. The DCT-based watermarking algorithm embeds a random sequence as the watermark signal into the magnitude components of significant DCT coefficients (selecting the top n coefficients with large magnitudes as significant components). A similarity function is defined to verify successful watermark extraction. Experimental results demonstrate the algorithm's imperceptibility and robustness against common image processing operations.