How would you find the height of objects given an image?

Question

This isn\'t exactly a programming question exactly. I just want to know what your approach would be to a common problem in Digital image processing.

Let\'s say you

Answer 1

I would rely on an object of known dimensions to be present in the picture. For instance, a man.

Or perhaps, we could use the EXIF data to reverse engineer the size of the object based on the camera's sensor dimensions, the lens and the focal length used. This again depends on the angle. We should be getting most accurate results when the camera has been held perpendicular to the subject.