find the the gravity

I have amorph shape in my picture, how can i find the gravity and auto draw a rectangular around it of find gravity and the width and height of shape. I used (regionprop (BW,'centroid') to find center but in this section i have problem. first i defined that any z>0 must be calculated, but the result was to strange. i

Answer 1

[Image Analyst]

Did you run my Image Segmentation Tutorial? http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862 All you have to do is replace Centroid by WeightedCentroid and it will give you the center of gravity. Centroid does not do that - it assumes all pixels in the blob are weighted the same (have the same gray level), in other words, it uses only the binary image, not the grayscale image.