How to locate valley points in palm print using matlab

Hello,

with respect to the above images, how can I identify and locate valley points as shown in the second picture using matlab.

Thank You

Answer 1

[Image Analyst]

Normally we don't give extensive algorithm development advice, though here's what I'd try

1. threshold the image: binaryImage =grayImage > 0
2. find the centroid with regionprops()
3. call bwboundaries() to get edge coordinates
4. remove all coordinates with y values above the centroid in the image.
5. get a distance vector giving distance from centroid to all edge coordinates
6. find the two biggest distances. They will go from center of palm to tips of outer fingers
7. extract only distances between these points, which will go across the fingers
8. threshold this to find distances shorter than some amount
9. call regionprops() on that go get the centroid of each valley

Give it a try.

[Image Analyst]

Also see sections 21.4 and 21.6 here: http://iris.usc.edu/Vision-Notes/bibliography/contentspeople.html#Face%20Recognition,%20Detection,%20Tracking,%20Gesture%20Recognition,%20Fingerprints,%20Biometrics

http://www.mathworks.com/matlabcentral/fileexchange/30845-shape-context-based-corresponding-point-models

http://www.mathworks.com/matlabcentral/fileexchange/32696-2d-line-curvature-and-normals

[Shirah]

Thanks for replying. I will give it a try and revert back if there is any query. Thanks again.