Efficient Algorithm Of Wavelet Lift Scheme And Application In Digital Image Processing

Wavelet theories and their application is an important subject. This thesis focuses on the construction of the biorthonormal integer wavelets with parameter based on lifting scheme. Lifting scheme is used for constructing the conventional wavelets.It is a method of constructing wavelets in space domain.The motif of the method is that you can lift the sample multi-resolution to the multi-resolution that you want. Thus, you can build your own wavelets based on what you want according to the lifting scheme. This paper introduces the engineering application in image compression, digital watermark and image fusion based on discussing of the biorthonormal 9/7 integer wavelets with parameter.This paper proposes some modifications to the SPIHT algorithm. It is based on the idea of the insignificant correlation of wavelet coefficients among medium- and high-frequency subbands. In this scheme, insignificant wavelet coefficients that correspond to the same spatial location in the medium subbands can be used to reduce the redundancy by a combined function proposed in associated with the modified SPIHT. In high-frequency subbands, the modified SPIHT proposes a dictator to reduce the interband redundancy. Experimental results indicate that the proposed technique improves the quality of the reconstructed image in terms of both the peak signal-to-noise ratio (PSNR) and the perceptual results over the original SPIHT at the same bit rate.A novel wavelet based watermarking scheme for copyright protection of digital image is presented. With this method, watermark was scrambled through Arnold transform before it was embedded. To embed the watermark robustly and imperceptibly, watermark bits are added to the significant coefficients of each subband selected by considering the human visual system (HVS) characteristics. From the experimental results it can be observed that proposed method is robust to wide variety of attacks.A new robust watermarking algorithm in DWT (discrete wavelet transform) domain is presented. Due to good randomness and easy reproducibility of chaos,the watermark is firstly permuted by the hashed chaotic sequence. To embed the watermark robustly and imperceptibly, watermark bits are added to the significant coefficients of each subband selected by considering the human visual system (HVS) characteristics. From the experimental results it can be observed that proposed method is robust to wide variety of attacks and also superior to the similar method in the literature. The usefulness of multilevel chaotic keys and privacy of modification to frequency coefficients enhance the security of watermark information.A novel multi-focus image fusion method using wavelet contrast and neural network is proposed. Firstly,source images are decomposed with wavelet transform (WT) and wavelet contrasts are obtained. Some of them are selected as sample for training neural network. Then,output wavelet coefficients of fused image though neural network and verify them by consistency. Finally, the fused image is obtained with inverse WT. Experimental results show that the proposed method outperforms traditional wavelet transform (WT) method for image fusion.Curvelet develops from wavelet theory, but it has several incomparable advantages on image processing. As to the edge and curve feature of the image, curvelet analysis offers a more precise way than wavelet multiresolution analysis. In this paper, after a research on the characteristics of curvelet transform, a novel fusion method based on curvelet transform is proposed. The fused images are obtained through merging various remote sensing images and medical images by applying this image fusion method respectively. Comparing with other methods and appraising on objective and subjective performance, this method can display information of the each input image and fuse details of input images successfully. Results show that the proposed method outperforms the traditional approach both visually and quantitatively.In the end, a discussion and analysis of promising research way based on this paper is presented, including lifting scheme of wavelet-based compression techniques for the multi-dimensional image,multicast watermarking protocol based on watermarking algorithm,objective evaluation method for image fusion based on wavelet lifting scheme.