Blind Digital Watermarking Algorithm Based on Quantization in Contourlet Domain

We present a blind digital watermarking algorithm using the module arithmetic and odd-even quantization based on Contourlet transform in this paper. After Contourlet transform, original image is decomposed into a series of multiscale, local and directional subimages. Select the low frequency sub-band as the watermarking embedding domain and then make module arithmetic. At the same time, the original binary watermark is firstly scrambled by two-dimensional Arnold transform, and then embedded into the selected sub-band. Then the coefficients of low frequency sub-band are modified using the odd-even quantization. The retrieving watermark algorithm is a blind detecting process, and it does not need original image. The experimental results show that the proposed watermarking algorithm is able to resist attacks, such as JPEG compression, noising, cropping and other attacks, and the watermarking is invisible and robust.