Copyright protection for digital imagesNowadays, the copyright protection problem of digital works becomes the urgent and necessary requirement. The paper proposes the method of watermarking approach for copyright protection with still images in DWT (Discrete Wavelet Transform) domain, finds out the optimal parameters for embedding and detecting watermark, and estimates the its robustness in comparison with algorithm using traditional DCT (Discrete Cosine Transform). Unlike some algorithms before, the optimal watermark is added to maximum coefficients of the approximation band in Wavelet domain to enhance the robustness. We also use two keys: one for watermark and another for generating embedded multi-bits to reinforce the security. Besides, lots of various attacks such as compression (JPEG and JPEG2000), filtering (average, median, adaptive, sharpening, Gaussian, etc) and noise are investigated with different type of images. Based on these results, the paper also proposes the solution for verifying on kit DSP TMS320C6711.
