Image watermarking algorithm based on DC components implementing in spatial domain
空域中实现基于DC系数的图像水印算法*

It was noted that most of the existing watermarking algorithms were performed only in the single spatial domain or frequency domain, this paper proposed a novel blind watermarking algorithm which combining with both advantages for color host images. By utilizing the generating principle and the distribution feature of direct current (DC) coefficient in DCT transformation, firstly, it calculated the DC coefficient of each 8×8 block of the Y luminance directly in spatial domain to create the quantization table. Then, it modified all pixel values of each block to embed watermark in the spatial domain instead of in the DCT domain. In addition, the watermark might be extract from the watermarked image without the original watermark and the original host image. Experimental results show that the proposed method not only has the higher robustness that is the advantage of frequency domain, but also has lower-computation complexity that is the advantage of spatial domain.