Estimation height from 2D grayscale image.

I have 2D grayscale image and wanted to measure size and depth of each region. I able to measure the size by using regionprop but no idea on finding the height.

Like topoghraphy concept,iIs it possible to estimate the height (depth of each hole) by using this way (imcontour) as I do not have information on z scale. I will find the max and min intensity of grayscale and put the ratio of the height.

Does it make sense?

[KALYAN ACHARJYA]

Are you asking depth? ..like stereo vision? The length / height / width of the objects different and depth is a completely different issue in my understanding?

[iza sazanita isa]

Yes, true. I want to find the depth of each hole. Lets say I find the maximum and minimum depth from the segmented images and then ratio it to the measured depth (from experimented work) , hence I will have standard range to find the depth from the image.