A depth camera is a fantastic little device to capture images and estimate the distance of objects from the camera itself, but, how does the depth camera retrieve depth information? Also, is it possible to reproduce the same kind of calculations with a normal camera?

A depth camera, such as Microsoft Kinect, uses a traditional camera combined with an infrared sensor that helps the camera differentiate similar objects and calculate their distance from the camera. However, not everybody has access to a depth camera or a Kinect, and especially when you're just learning OpenCV, you're probably not going to invest in an expensive piece of equipment until you feel your skills are well-sharpened, and your interest in the subject is confirmed.

Our setup includes a simple camera, which is most likely integrated in our machine, or a webcam attached to our computer. So, we need to resort to less fancy means of estimating the difference in distance of objects from...