How to get the topmost and the bottomost coordinates in a binary image?

I have a binary image with background black...I need to find out the topmost coordinate point for the object and bottomost point also...if there are two or more topmost/bottomost points(if the object is flat at the top/bottom) then I need only the extreme point either the leftmost or the rightmost......can any one help...any help is appreciated

Answer 1

[Image Analyst]

I did help, in your duplicate question: http://www.mathworks.com/matlabcentral/answers/230334#comment_298988

Answer 2

[Image Analyst]

Here is the demo I posted in your duplicate question. See the attached demo.