how to define a region of interest in an image to perform different scanning on dat particular area?

i have a image with two white spots x-ray reflected intensity, first 1 is direct beam spot with high intensity and second 1 is reflected beam with less intensity on same y axis.i want to calculate intensity of lower spot without cropping the image?

Answer 1

[Image Analyst]

You have to make a binary image which you can then pass into bwconncomp() and regionprops(). See my Image Segmentation Tutorial in my File Exchange for a full demo. http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862