Color Image Watermarking Algorithm Based On Chaotic Sequences And Wavelet Transform

Along with the development of Internet and Communication multimedia techniques, copyright protection of multimedia has become increasingly prominent. Watermarking technology which is the most effective method on the issue of copyright protection has attracted more and more attention at present. In this paper, theory analysis and numerical experiment are combined to study the color image watermarking.To increase the security of the watermark, a new binary image encryption algorithm based on TD-ERCS map is presented. The watermark is encrypted by a chaos sequence generated by TD-ERCS map; A novel color image watermarking algorithm is proposed based on discrete chaotic map and 2-dimensions discrete wavelet transform. The watermark is encrypted by the new binary image encryption algorithm, and the encrypted watermark is embed into four sub-bands of the most deep level of blue branch of host image by three-level wavelet transform, and the embedded positions are determined by general cat chaotic map; A novel color-image blind detection watermarking algorithm is proposed based on integer wavelet transform and subsampling. The scrambled watermark is encrypted and embed into the low sub-bands after four sub-images of the Y branch of host image is transformed by two-level wavelet transform, and the embedded positions are determined by Logistic chaotic map, this watermarking scheme can realize blind extraction.Simulation and property tests are based on Matlab7.0.1. The experiment results demonstrate that the proposed algorithm keeps the quality of the image well and is robust enough to JPEG compression, noise, filtering, image enhancement, histogram equalization, cropping and rotation etc. The watermark is encrypted before embedding which ensures the safety of the watermark.