Contour Detection - Image processing

Dear Image processing experts, The image processing requirement is to detect the contours of human face in image using C, C++ or C#. Seven coordinates are manually place along the face contour. Please refer to the attached image [login to view URL] to see the sample coordinate placement. If we draw a bezier/spline curve along the five points, the line may almost passing through the face contour. But it is not accurate for many cases. Hence we need face contour detection. The inputs and output for the system is as follows input 1 : one rbg image input 2 : 7 coordinates along the face contour. output : draw line along the face contour. I have attached 30 images ([login to view URL]) which shows real cases. You may notice that in some cases the boundary between the face and neck is very vague. In the [login to view URL] you can see file name with following extension. The meaning of them is, *[login to view URL] -> shows the 7 manually placed coordinates as red dots *[login to view URL] -> the original image, where you can do your experiments I draw the expected contour for first 3 of them (ground truth). Some thoughts: You are welcome to use opencv or such opensource libraries. You may use algorithm such as "active contours", "graph cut", but it is up to you. We dont need a full face segmentation, instead just the contour connecting the manual positioned points. We have nothing to do with face detection. Just find the accurate contour connecting the manual keypoints. C# is more preferred to C++/C. Happy bidding.