[JamesBrown]

This doesn't look like Delphi, it is image processing stuff in C.

I hate to sound like a jerk but if you don't know what to change you don't understand the code. You really need to read the code and play with it until you know what is doing what. Once you understand what the code is doing find academic publications on facial recognition software, particularly emotion analysis stuff. This will explain the algorithms and filtering that you need to use to find only the mouth corners.

Quite frankly there is no reason to edit someones code until you know what it does. If we review the code and tell you what to change you aren't going to get anything out of it. I have done some work with other peoples image processing software. Often code I could not have written by myself however I made sure I understood it before I changed anything.