Given a colour image whose light intensity is dim at the edges and bright in the middle, such as **[dim    bright    dim]**, which computer vision technique would be recommended to correct this imbalance? 

While I believe [Histogram Equalisation][1] could help, I've read that it also introduces an unrealistic look to an image by exaggerating the blue channel.

I consider implementing an image processor for this task.


  [1]: http://docs.opencv.org/trunk/doc/py_tutorials/py_imgproc/py_histograms/py_histogram_equalization/py_histogram_equalization.html