Digital image watermarking based on regularized filter

This paper presents a spatial domain image watermarking method based on regularized filter. In the proposed method, a watermark image is embedded into a host color image directly by modifying the blue color component. The watermarkmark strength is controlled by two factors, i.e. a constant value and the luminance within a local embedding area. The prediction of the original host image is obtained from the watermarked image by using the regularized filter, so that the embedded watermark can be blindly recovered by substracting the predicted image from the watermarked image. Set of experiment are carried out to verify our proposed method. The results show that the accuracy of the extracted watermark in terms of NC was higher, compared to the previous method. The robustness comparison between both methods against different types of attacks is also performed and presented.