Color Image Watermarking Using Discrete 2D Wavelet Transform

This is a color image watermarking program based on Discrete 2D Wavelet Transform (DWT). The program accepts an original image and a logo as inputs, and directly generates images with embedded watermark effects. By utilizing the multi-resolution analysis characteristics of wavelet transforms, the program embeds watermark information into the original image through frequency domain decomposition and reconstruction processes, achieving image protection and authentication capabilities. The implementation employs DWT algorithms to decompose images into approximation coefficients (LL) and detail coefficients (LH, HL, HH) across multiple resolution levels, where watermark data is strategically embedded in selected sub-bands based on human visual system properties. Through this watermark embedding process, the program effectively prevents image tampering and unauthorized copying while providing traceability and verification functionality for digital images. The system features a user-friendly interface where users simply input source images and logos to obtain watermarked images, with the underlying algorithm handling color channel processing (typically RGB or YCbCr space) and optimal embedding strength calculations. This watermarking solution has broad application prospects in digital image processing and information security fields, particularly for copyright protection and content authentication in multimedia systems.