Loading cubemap faces as individual surfaces

I’m trying to do some image processing on a cubemap (CPU side), and it would be helpful to have a function that returns an array / vector of surfaces: one per face of the cubemap.

I noticed that Cinder’s Texture.cpp has the exact functionality I’m looking for with calcCubeMapVerticalCrossRegions and calcCubeMapHorizontalCrossRegions. However, those functions are in an anonymous namespace, inaccessible to my code. Maybe this functionality is exposed elsewhere and I missed it? I realize I could crop the image manually or just use the code from the functions above. Just wanted to see if there was an easy solution. Thanks for any help in advance!