Color image watermarking in YUV color space based on combination of DCT and PCA

In the color image watermarking in DCT domain, the watermark bits are inserted into a range of DCT coefficients of the cover image. The watermark embedding into the low-band is not suitable in term of invisibility of the watermark and the quality of the watermarked image. In this paper a new method is proposed using a combination of the DCT and PCA transform in order to use the low-frequency band for the color image in YUV color space. The color image is transformed into YUV from RGB color space and the luminance (Y) component is divided into non-overlapping blocks and the low-band coefficients of each block are placed in the matrix data, the PCA transform will be applied to it. The first component of the PCA (PC1) has the maximum energy concentration, So the watermark is placed within it, because the watermark is more resistant against attacks. Also the our method is compared to other DCT methods. Our method is robust and keeps the quality of the cover image.