Hi
With the Gimp image manipulation program, I frequently increase contrast by using the color curve tool. From this:
to this:
(/upfiles/1387210577269045.png)
There is a small tutorial that talks about increasing contrast here: http://docs.opencv.org/doc/tutorials/core/basic_linear_transform/basic_linear_transform.html
Therefore, I assume this operation would give the desired effect:
image.convertTo(alpha: 1.3, beta: -20)
I would have to calculate the exact alpha and beta values in order to exactly represent the above color curve. Maybe anybody can comment on these assumptions?
Thank you very much.