BradLarson/GPUImage — pull request #1781 by r3mus (2014-09-24 21:35:07+00:00)
Title: Added intensity property to GPUImageLookupFilter

Based off of the SO answer here: http://stackoverflow.com/questions/23804661/gpuimagelookupfilter-with-intensity-control

Tested on iOS 8 only, probably requires further testing on iOS 7 and definitely OS X.