A New Chromatic Color Image Watermarking and Its PCA-Based Implementation

This paper presents a color image watermarking scheme based on spatial information analysis in spatio-chromatic space. Principal component analysis (PCA) is used as an appropriate tool for estimating information. We use RGB color images with a regular arrangement RGB channels into spatio-chromatic space, and PCA performs de-correlation of these signals. We show that spatio-chromatic principal components of images contain spatial information and color information, and that PCA spatio-chromatic analysis is able to help the reconstruction of full images. We propose an efficient watermarking method for color images based on the observation. Watermarks are embedded in some spatio-chromatic principal components of the image, which provide invisibility and robustness. The experimental results show that the proposed method possesses robustness against most common attacks, and image processing techniques.