Research On Walsh And Slant Transforms And Their Applications In Digital Watermark

More and more attentions have been paid to The Nonsinusoidl Family Orthogonal Transforms and great progresses have been made not only in theory but also in applications in the past few yeas, but there is something worthy of further researches.The transforms which based on Walsh Transform and generated through copy and mutation Bisection evolution technology have reached much recognition for their fast and simple operations. The one-dimensional fast algorithms of these transforms have been implemented extensively, and which is the basis of the two-dimensional or three or higher dimension fast algorithms. Especially taking the two-dimension transform for example, it has great advantages in image processing and can reduce the computation time efficiently, so it is fit for real-time transform and compression techniques.According to the different sequences of the rows of the transform matrixes, it can be divided into four classes: Paley-order(P order), Hadamard-order(H order), Walsh-order(W order) and M-order(M order). The former three orders have received more researches, but the latter one has been researched little and deserves more attention.With the advent of information era, the problems of information safeties are becoming more and more obvious, and how to protect the copyright of digital products is one of them. Nonsinusoidl Family Orthogonal Transforms play an important role in this new filed. In this paper the Walsh and Slant Transforms application in digital watermarking is discussed, and according to the properties of them, the watermarking imbedding and distilling algorithms are designed for the image and video by using different ordered transforms.For the image watermark, the H order and M order algorithms are applied and the similarities and differences are discussed. For the video watermark, the W order algorithm is applied for it has some properties similar with DCT transform and performs better in MPEG compression coding.The experimental results show that the proposed watermark technique is not only invisible to the image but also robust to attack. The image algorithm is better for the images whose brightness are changed gradually especially; and the video algorithm is robust to the MPEG compression and normal attacks. Based on the fast matrix transforms, the algorithms in this paper are very suitable for real-time processing. Moreover, it is meaningful and practical because it is a blind watermark which needn't original image when distilled.