Research On Some Problems Of The Image Processing Based On Wavelet Transform

Wavelet transform is a new tool of time-frequency analysis after Fourier analysis and is widely applied in the scientific research and project technology. Though wavelet theory has been somewhat perfect, its applied research still has been developed and renovated. The image processing field where wavelet transform is applied almost includes the whole image processing aspects. Three aspects,image denoising, image fusion and digital watermarking, have been researched in the paper. Based on the analysis in these research actualities, some algorithms and ideas have been proposed and the relevant test result and analysis have been given. The main research contents are as follows.At present, the image denosing algorithms based on the wavelet transform are analyzed in details, and the H-Curve criterion which can fix a more reasonable threshold and be more widely applied is introduced. Its scientific nature and reasoning process are illustrated in the theory aspect. According to more advantages in some aspects over real wavelet transform, complex wavelet can improve the image precision when it was decomposed and composed, and its theory basis is illustrated in details here. So combing the dual-tree complex wavelet transform and H-Curve criterion, some relative denoising tests are carried out, and after the results are analyzed and compared,it shows that this algorithm can produce a better denoising effect.The advantages and defects in the general pixel level image fusion methods are compared and analyzed, and it shows that the image fusion method based on the wavelet transform can acquire a better fusion effect. At present, the general image fusion algorithms have not fully taken into account the human vision characters, thus sometimes the fusion result fails to get perfect fusion effect. The human vision system (HVS) is introduced into the image fusion, and combing the wavelet transform and fuzzy theory, a new image fusion algorithm is presented. Based on the HVS experience model in the wavelet field, the new algorithm precisely depicts the eyes sensitive image information, such as edges, textures, high bright domain, etc. Then the weight coefficients are adaptively calculated out based on the fuzzy theory. Last, the image fusion is achieved by the adding weight average in the wavelet field. In contrast with the algorithms in common use, this new algorithm can produce a better fusion effect.In order to insure the watermarking embedding advantages, such as high speed, easy realization, etc, and improve its safeness and robustness. Using the chaos system better characteristics, a meaning binary image is quickly encrypted based on chaos theory. Then according to the principle which the zero tree coding, a image compress method, constructs the zero tree, the wavelet coefficients are arrayed by their...