Detect U Shaped Edges in an Image [closed]

Question

I'm trying to detect the location of a fingertip from an image. I've been able to crop out a region in the image where it must have a fingertip, and extract the edges using Canny Edge Detector. However I'm stuck. Since my project description says I can't use the skin color for detection, I cannot find the exact contour of the finger, and will have to try to separate the fingertip with edges alone. Right now I'm thinking since the finger has a curved arch shape/letter U shape, maybe that could be used for detection. But since it has to be rotation/scale invariant, most algorithms I found so far are not up to it. Does anyone have an idea of how to do this? Thanks for anyone that responds!

This is the result I have now. I want to put a bounding box around the index fingertip, or the highest fingertip, whichever is the easiest.

Answer 1

You may view the tip of U as a corner, and try corner detection method such as the Foerstner Algorithm that will position of a corner with sub-pixel accuracy, and Haris corner detector which has implementation included in the feature2D class in opencv.

There is a very clear and straighforward lecture on Haris corner detector that I would like to share with you.