Fog-removing Processing of Image through Homorphic Filtering Based on Wavelets Transformation
Lin Yin · Journal of Longyan University · 2008
This article uses homomorphic filtering to remove the fog.By improving the traditional homomorphic filtering,we introduce a new spatial-frequency analysis method based on wavelets which is applied to homomorphic filtering to enhance the contrast of an image.In order to attenuate the low spatial frequencies and amplify the high spatial frequencies,the wavelet analysis coefficients are processed by the Butterworth filter.So the local uneven distribution due to non-uniformity of light source can be reduced and the object feature can be emphasized.Experiments have shown that the method performs well in enhancing the local contrast while maintaining its global appearance.