how to plot a graph which count transitions in a binary image from black to white regions

Answer 1

[Image Analyst]

I assume you have the x,y coordinates of the perimeter of the circle. Then you can just use improfile() and call diff() and look for changes of +1.

values = improfile(binaryImage, xCircle, yCircle);
dv = diff(values);
numTransitions = sum(dv==1);

Of course you'll have to take special care at the ends of the array, like if the white part started exactly at element #1 and was zero at the very last element.

[syeda musfia]

thanku for the response. actually i wanted to count the number of active fingers in the image. can u please show me how to do it.

[Image Analyst]

Well you'll have to examine the profile to see if it's crossing narrow fingers or the much larger palm of the hand.

If you don't want to do that, then you can adapt apps by Dirk - he has lots of hand apps: http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A29180