Image Watermark Technique Based on Digital Holography and Ridgelet Transform

A novel image watermark algorithm based on digital holography and ridgelet transform was designed by taking the advantage that ridgelet transform domain is a most suitable representation of image´s linear outline edge features. Firstly, the image was divided into blocks, and each block was transformed by finite ridgelet transformation. Secondly, the digital holography watermark is embedded into the most energetic coefficients of ridgelet . A correlation function is used in the watermark detection process and the original image is not required. Experimen result shows the watermark is robust to noise,medial filtering , JPEG2000 lost compression and cropping. By comparating respectively with paper and paper, the result shows the proposed algorithm is more superior to them.