how calculate orientation of minutia(end point,bifurcation) relative to x axis in fingerprint image

hello . I have fingerprint gray scale image . I extract coordinate of minutiae . but I don't know how to calculate the orientation of end point and bifurcation. can anybody help me to write matlab code of it? in my image end point is marked with red. bifurcation marked with blue

[GOPEE Ajit Kumar]

Hello I would like to know how you have generated such an image (I mean with thinning). I am using FVC 2002 fingerprint images with gray scale on which I wish to carry out thinning. Also do you know how to locate singular points in fingerprint images? Thanks in advance.

[indrani dalui]

please help me to givein a code ..after orientation bifurcation of thinning image how to calculate the scor for matching thinned image.thanks in advance

Answer 1

[Image Analyst]

Get the endpoints, which it looks like you can already do. Then get the x,y coordinates of the points connected to that. A variety of ways to do that such as bwdistgeodesic http://blogs.mathworks.com/steve/2011/11/01/exploring-shortest-paths-part-1/

Then take the points closest to the endpoint, say 5 or 10 or whatever you want, and use polyfit to fit a line to the. I've attached a polyfit demo.

[zohre saeedi]

thanks for your answer. but it isn't my answer. I want to compute the orientation of each minutiae relative to x axis.

[Image Analyst]

If you don't care about the line that the endpoint is attached to, then just calculate atan2(y,x) or the slope relative to the origin y/x. If you would just show a diagram for how you want the "orientation" of one of the endpoints to be determined, then maybe we could go directly the the solution you want, instead of guessing.

[indrani dalui]

respected sir , i am a student doing a project of fingerprint recognition i have extract ridge end and bifurcation from fingerprints image..now i want code for "ridge end and bifurcation point count from extraction ..please help me.

[Image Analyst]

To count the ridges, use bwlabel(). To find endpoints, call bwmorph() then call bwlabel()

[~, numRidges] = bwlabel(binaryRidgeImage);
endPoints = bwmorph(binaryRidgeImage, 'endpoints');
[~, numEndPoints] = bwlabel(endPoints);