The Application of Wavelet Transform in Digital Image Processing

The edge is the most important high-frequency information of a digital image. The traditional filter eliminates the noise effectively. But it will make the image blurry. So we should protect the image of the edge when reduce the noise of the image. The wavelet analysis method is a time-frequency analysis method which selects the appropriate frequency band adaptively based on the characteristics of the signal. Then the frequency band matches the spectrum which improves the time-frequency resolution. The wavelet analysis method has an obvious effect on the removal of noise in the signal. The paper outlines the principles of wavelet analysis. According to the features of the multi-scale edge of the wavelet, we analyze the de-noising method of the orthogonal wavelet transform which based on soft and hard threshold. A de-noising method is put forward based on the wavelet transform to address this dilemma of the noise reduction and protection the image edge, and realizes the de-noising of two-dimensional image signal based on MATLAB.