There are a variety of different methods for calculating depth, all with different strengths and weaknesses and optimal operating conditions. It doesn’t really matter what color values the depth map uses, this is just displayed in this way to make it easy to visualize. In this case, cyan is closest to the camera, and red is furthest. The output from a depth camera can be displayed in a variety of ways – in the example below, the color image is shown side by side with the depth image, where each different color in the depth map represents a different distance from the camera. A depth camera on the other hand, has pixels which have a different numerical value associated with them, that number being the distance from the camera, or “depth.” Some depth cameras have both an RGB and a depth system, which can give pixels with all four values, or RGBD. Thousands to millions of pixels together create the kind of photographs we are all very familiar with. Each attribute has a number from 0 to 255, so black, for example, is (0,0,0) and a pure bright red would be (255,0,0). Each pixel has values associated with it – usually we think of those as Red, Green and Blue, or RGB. Standard digital cameras output images as a 2D grid of pixels. In this post, we will cover a variety of types of depth cameras, and why the differences are important, what depth cameras are, how you might get started and more.

This post assumes the opposite – that you know nothing and are brand new to depth. We talk a lot about depth technologies on the Intel® RealSense™ blog, for what should be fairly obvious reasons, but often with the assumption that the readers here know what depth cameras are, understand some of the differences between types, or have some idea of what it’s possible to do with a depth camera.

Kinect projected ir pattern