A digital watermarking algorithm for color images using image correction

Abstract

This paper presents a new robust watermarking extract scheme for color image by using scale invariant features transform image correction. A binary watermark image is permuted with sequence numbers generated by a secret key in a spatiotemporal chaos system. Then, the binary image watermark was encoded by Gray code, and then adaptively embedded into low frequency components of discrete cosine transform domain in the original color image's blue channel. In watermarking extract scheme, the scale invariant features of images are extracted, and the match points between the watermarking image and the reference image are found. Then the watermarking image is corrected by affine transform of these match points. Although the watermark is only embedded into the blue channel, the other channel can provide the position information of the image processing operations. By comparing the intensities of the low frequency components of discrete cosine transform domain of the corrected and the original image, the extraction method of the watermark is calculating the probability of detecting '0' or '1'. At last, the watermark is extracted from the corrected image. Experimental results show that the proposed scheme is robust and secure against a wide range of image processing operations such as global affine transformation, filtering and lossy compression.