Watermark Embedding into Wavelet DC Components

A watermarking scheme is presented to embed watermarks into wavelet DC components. The DC area is not suitable for embedding watermark because of severe visual degradation. To overcome degradation problem, we embed watermark into visually insensitive locations. To detect visually insensitive locations, we perform medianfiltering to the lowest frequency sub-band of wavelet transform. The robustness of our technique is compared with method based on further wavelet transform to the lowest frequency sub-band. Experiments show that our method is more robust to JPEG compression, median-filtering, and sharpening etc.