How to get the distance to camera that objects detected in a photo by Monocular camera

I am wondering if it is possible to get the object's distance to camera in a photo. I hear that there are some calibration method, but I know very little about this, and I don't know how to get the position information by this. I'm looking forward someone to tell me that.

Answer 1

[Image Analyst]

It's not possible in ALL cases. For example if you have an image of the moon, how do I know if it's 3 meters away because it's a poster on your wall, or if it's the real moon thousands of kilometers away? You wouldn't.

But in some cases you can. There is a Camera Calibration capability in the Computer Vision Toolbox that you might want to look at.

https://www.mathworks.com/products/computer-vision.html#camera-calibration

In addition there are now an increasing number of cameras coming to the market that can give you a distance image directly.