DefinePK

Abstract

In image processing, contrast enhancement is an essential task due to the capability of improvement in image visibility. For improving the quality of the picture, the noise should be reduced, and the contrast should be high. The existing image enhancement methods do not have better performance when the model has a dark background. To overcome this issue, this paper proposes a hybrid of Recursively Separated and Weighted Histogram Equalization and Power law transformation algorithm using DWT. DWT is used for the noise reduction, and RSWHE combined with Power law transformation is used for improving the brightness of the image. RSWHE algorithm enhances the low frequency components of the image, whereas the Power law transformation enhances the high frequency components of the image. This algorithm is combined with DWT and a Wiener filter as the denoise filter, to enhance the low contrast image to high contrast with less noise and by having weighting function which smoothens each sub-histogram of pictures and also decreases the effect of increasing intensity on a color image. Results illustrate that the proposed hybrid RSWHE-Power law transformation using DWT has improved performance in the image enhancement of the dark image. The contrast of the input image is highly improved with the proposed technique.