How to find the angles between three consecutive pixels in an binary image ?

I have a binary image(alphabet) who's edge matrix i have, now i need to store all the angles formed between three consecutive pixels of the edge in an array and do a histogram plot.

Answer 1

[Image Analyst]

Check out Loren's answer and ROger Stafford's answer at the bottom of this link: http://www.mathworks.com/matlabcentral/newsreader/view_thread/236492

[Dipak Majhi]

sir, in that question some points are given and the angle is to be found out,but i don't know the points of my binary image,how to trace every point and get all the edge angles formed

[Image Analyst]

I don't know. Maybe you want to skeletonize with bwmorph() it or maybe you want to use bwboundaries().