An improved color image watermarking algorithm based on QR decomposition

Most of the existing color image watermarking schemes use binary or grayscale image as watermark, and many of them belong to non-blind watermarking methods. In this paper, an improved color image watermarking algorithm based on QR decomposition is proposed to embed color watermark image into color host image. For embedding watermark, the 24-bits color host image is divided into non-overlapping 3?×?3 pixel blocks and each pixel block is...