Research On Image Enhancement Based On Mluti-wavelets Transform

Thorough research on image processing is necessary since the wider use of image processing technology. As an important part, image enhancement serves as a link between the preceding and the following in the whole process of image processing. Due to strong pertinence, there is no universal method of image enhancement.Multiwavelet theory is getting increasingly mature with the development of wavelet theory. Compared with single wavelet, multiwavelet can combine many advantages, such as orthogonal, symmetrical,compactly supported and high orders vanishing moments. With the need of multi-channel filter designing, multiwavelet theory develops quickly in recent years.This paper studied image enhancement based on multiwavelet theory. The main contributions are summarized as follows:An overall study on image enhancement problems is made in this paper. Properties, MRA, decomposition and reconstruction of multiwavelet theory are studied specially. Analyzing the basic method of image enhancement, many experiments are carried out in order to proving its effectiveness.Based on an intensive study on the choice of wavelet decomposition layers, the choice of wavelet method and more, this paper proposes two image enhancement algorithms.Taking advantage of features of decomposed image, histogram equalization and principle of image fusion, a method of image enhancement based on multiwavelet transformation and image fusion is proposed and verified. Given features of fingerprint, this paper put forward the other algorithm, which process low frequency and high frequency sub-images respectively in combining advantages of Gabor filter and direction filter appropriately.On the basis of previous studies, this paper studied and discussed the image enhancement based on multiwavelet transform. May it could play a certain role in promoting further research work in the relevant areas.