My question is if I have a Lion image just I want to change the color of the lion alone not the background color. For that I referred this SO question but it turns the color of whole image. Moreover the image is not looking great. I need the color change like photoshop. whether it is possible to do this in coregraphics or I have to use any other library.
EDIT : I need the color change to be like iQuikColor app
Here is the sketch of a possible solution using OpenCV:
cvCvtColor(we only want to change the hue).
cvThresholdspecifying a certain tolerance (you want a range of colors, not one flat color).
cvInRangeSand use the resulting mask to apply the new hue.
cvMergethe new image with the new hue with an image composed by the saturation and brightness channels that you saved in step one.
There are several OpenCV iOS ports in the net, eg: http://www.eosgarden.com/en/opensource/opencv-ios/overview/ I haven't tried this myself, but seems a good research direction.