how to calculate area of objects in certain region of an image.

Hi i have an grayscale image which has objects all over the image. I want to know the area of the objects in certain regions of the image. I have divided the image in four quadrants using hline and vline and applied in polygon to define each rectangle region. but now i want to calculate the total area of objects residing in each rectangle. but regionprops() doesn't seem to cut it. I'm at a loss about how to do so.

[Walter Roberson]

How do you want to calculate for objects that cross a quadrant boundary?

[KSSV]

Attach an image so that people can help you around. Simply a question might not give an idea.