Need some help with a project (image transformation)

Hi,

I am working on a project where I am designing an application that will allow someone to upload a picture and then manipulate certain parts of the image with a slider control. Essentially, the sliders allow the person to see what he or she will look like after gaining weight (it is for an obesity awareness program). However, I don’t really know what kind of code I should be looking at, particularly when it comes to a) identifying areas such as the cheeks, chin etc on the image, and b) applying the relevant transformations to those areas. I have been looking at http://www.miniclip.com/games/putty-face/en/ and that is similar to what I want to do except rather than mold the face like putty, the sliders provide a more fixed transformation. I have been looking at using displacementMap filters and matrix transformations but am rather stuck. any advice or help would be greatly appreciated.

Thanks,

Kiks