Single parameter Image local contrast enhancement using undecimated wavelet transform

Image local contrast enhancement is an important part of image quality improvement. Recently, a local contrast enhancement method based on undecimated wavelet transform was proposed, in which the detail coefficients during the ۴-level reconstruction process were weighted by a Gaussian function to increase the representation of edges with low contrast. We propose an improved variant where we reduce the number of parameters from ۸ to ۱ by automating the selection of variance of Gaussians and making their gains dependent on a single parameter which is controlled by the user effectively resulting in one parameter which controls the intensity of local contrast enhancement. The method was tested on different images and various image quality and image contrast metrics were utilized to assess the performance. Experimental results demonstrate that our method achieves higher performance in some image quality criteria compared to conventional local contrast enhancement methods: unsharp masking and multiscale retinex. The code and demo of this implementation are available at: https://github.com/salehrayan/SP-WLCE-local-contrast-enhancement.

Keywords:

Local Contrast , Image Enhancement , Undecimated Wavelet Transform , Luminance