Slant Haar-type And Walsh Transforms With Applications In Digital Watermark

With the popularity of network and the advent of the information age, information access has gradually been very advantage and shortcut. However , it also makes the copyright protection of digital products and security of network information more and more important. Digital watermarking as a new technology of copyright protection is a kind of leading technologies in information hiding and it gains widely research and application.Orthogonal transforms can be divided into sinusoidal transforms and nonsinusoidal transforms. Walsh transforms and Haar transforms are the most important members in nonsinusoidal transforms. They have very simple and convenient algorithm, so be applied in many areas. The slant Haar-type transform is discussed by using the idea of bisection evolution and mutation, and generates by combining Haar-type transform and slant transform. It has the excellence of Haar-type transform and slant transform. The algorithm is convenient, in-place, and very suitable for real-time processing.Firstly, a new digital watermarking algrithm based on slant Haar-type transform and Walsh transform is proposed in the paper. The algorithm makes full use of the advantages of slant Haar-type transform, like simple operation, flexible parameters and so on. It is especially better for the images whose brightness are changed gradually. On this basis, the paper then gives a new dual digital watermarking algorithm for color image. The algorithm realizes the advantages of high transparent , strong robustness, multi-function and large payload size. At the meantime, it adopts the self-restoring technology to make them in advance. The experimental results show that the proposed watermark algorithms are not only invisible to the image but also robust to attack. Because of the choice of embedded sub-block, the algorithms are very suitable for images whose edges are simple or relative concentration. Moreover, it is meaningful and practical because it is a blind watermark which needn't original image when distilled.