OpenCV Lip Segmentation

Question

How do people usually extract the shape of the lips once the mouth region is found (in my case using haar cascade)? I tried color segmentation and edge/corner detection but they

Answer 1

The color segementation involves "gradient of the difference between the pseudo-hue and luminance (obtaining hybrid contours)". Try googling for qouted string and you will find multiple research papers on this topic.

Answer 2

Here are two papers for lip segmentation using edge detection and color segmentation. Try them out.

paper1, paper2