LAB Image Watermarking Source Code for Embedding and Extraction

This text discusses MATLAB-implemented LAB image watermarking source code capable of performing image embedding and extraction operations. To better understand the implementation process, we can elaborate on the code's technical approach. During image watermark embedding, the code first loads both the watermark image and host carrier image into the program using MATLAB's imread() function. The implementation then applies Discrete Cosine Transform (DCT) to the carrier image through dct2() function, converting it into frequency domain representation. The watermark embedding process involves modifying specific DCT coefficients in the mid-frequency range to balance robustness and invisibility. After embedding, the code performs inverse DCT using idct2() function to reconstruct the watermarked image. For watermark extraction, the algorithm loads the watermarked image and reapplies DCT transformation. The extraction mechanism compares frequency domain characteristics between the original carrier image and watermarked image, utilizing coefficient differential analysis to retrieve the embedded watermark. The implementation includes error-handling for image format validation and employs quantization techniques to enhance watermark resilience against common image processing operations.