Vignette Removal

Implements single image vignette removal algorithms in C#

##Adaptive Segmentation Image Variation Vignette Correction

Implements Adaptive Segmentation Image Variation Vignette Correction as described in the paper "Single-Image Vignetting Correction*,by Yuanjie Zheng,Stephen Lin, etc."

Ported from the C++ version of the following: https://github.com/GUOYI1/Vignetting_corrector

##Log Intensity Entropy Vignette Correction

Implements Log Intensity Entropy Vignette Correction as described by "Revisiting Image Vignetting Correction by Constrained Minimization of log-Intensity Entropy"

Ported from the C++ implementation: https://github.com/HJCYFY/Vignetting-Correction

##Constrained Minimization of log-Intensity Entropy Vignette Correction

Implements "Torsten Rohfling: Single-Image Vignetting Correction by Constrained Minimization of log-Intensity Entropy"

based on code from https://github.com/dajuric/dot-devignetting