An Oblivious Watermarking Scheme Based on Coutourlet Transform and Quantization Index Modulus Modulation

This paper presents an oblivious watermarking scheme based on contourlet transform and quantization index modulus modulation (QIMM).The scheme has the following features. First, the proposed scheme makes better use of multidirectional characteristic of contourlet transform and embed the watermark into the 4 directional high pass sub bands. Second, the scheme avoids the problem of selection of wavelet filter banks since approximately the same results are obtained with different contourlet filter banks in watermark embedding and extracting stage. Third, unlike the conventional watermarking schemes, watermark error correction is integrated to enhance the quality and normalized cross correlation (NC) value of the extracted watermark. Fourth, through the introduction of the error correction, the proposed scheme tries to view NC as a standard to judge the watermarking algorithm. As a comparison, experiments are conducted to demonstrate that our scheme is more effective than the former one based on lifting scheme wavelet transform.