iOS - Change color channels levels programmatically

Is it possible to adjust color levels using Core Graphics?

I would like to adjust channels using parametrized curves in the Gimp or other grap开发者_Python百科hic editor style.

You can use this: ios-image-filters (like photoshop)

if you want to manipulate levels, here's your method, built straight onto the UIImage class:

- (UIImage*) levels:(NSInteger)black mid:(NSInteger)mid white:(NSInteger)white