Multipurpose color image watermarking algorithm based on IWT and halftoning

In the security of digital contents, almost all previous works tried to attend either the copyright protection issue or the content authentication issue, however recently some proposals try to solve simultaneously both problems. In this paper, a multipurpose method that tries to solve both problems for color images, using two watermarking algorithms, is proposed. The first algorithm is based on a self-embedding technique which uses the halftone version from the Y, Cr and Cb channels of the original color image as the watermark, then, the Quantization Index Modulation (QIM) method is used to embed in the integer Wavelet transform (IWT) domain. In the second algorithm, the halftone watermark image generated from luminance channel Y is watermarked manipulating their flipabble pixels to embed a bits sequence related to the owner's copyright information.