How do I equalize contrast & brightness of images using opencv?

Question

I\'ve got an image that I\'ve scanned, but the white paper is not white on the screen. Is there a way to equalize the contract/brightness to make the background whiter?

Answer 1

It is called equalizeHist. I do not know its name in emgu, but the result should be exactly what you need - brighter background, and darker text.

EDIT

To extract only the edges (which is very different from the image enhancement techniques) you can simply apply Canny. Select the two thresholds as 20 and 60, for start, and then increase (or decrease them) keeping a ration of 3:1 between them, until you have a good-looking edge image.