I need help regarding circular hough transform by Peter Bone

I need to detect the pupil of an eye. so what i did was:

A = imread('iris.bmp'); A = double(rgb2gray(A));

and copied the example on his houghcircle.m

mgBW = edge(A); rad = 24; [y0detect,x0detect,Accumulator] = houghcircle(imgBW,rad,rad*pi); hold on; plot(x0detect(:),y0detect(:),'r-'); figure; imagesc(Accumulator);

After doing this, i think i did not able to find the pupil.

[Sean de Wolski]

How similar is your profile picture to the other eyes you may be looking at?