Tech Behind Xbox 360's Project Natal Revealed

Learn where Project Natal came from and how it can work in the dark.

Did you think that Microsoft cooked up the technology for Project Natal on its own? Well, it didn't. Today an announcement hit the wire that Israeli company PrimeSense will be providing its 3D-sensing technology for use in Project Natal for Xbox 360.

"Xbox 360 Hardware Engineering teams developed the ‘Project Natal’ sensor based on the PrimeSensor reference design to support the special requirements of ‘Project Natal,’" said Aviad Maizels, president and founder, PrimeSense.

Now that we know the technology behind the Project Natal, let's dig up some more information from PrimeSense's website.

Method of operation

PrimeSense technology for acquiring the depth image is based on Light Coding. Light Coding works by coding the scene volume with near-IR light. The IR Light Coding is invisible to the human eye. The solution then utilizes a standard off-the-shelf CMOS image sensor to read the coded light back from the scene. PrimeSense’s SoC chip is connected to the CMOS image sensor, and executes a sophisticated parallel computational algorithm to decipher the received light coding and produce a depth image of the scene. The solution is immune to ambient light.

Technical Overview

The PrimeSensor is built around PrimeSense’s PS1080 SoC. The PS1080 controls the IR light source in order to project the scene with an IR Light Coding image. The IR projector is a Class 1 safe light source, and is compliant with the IEC 60825-1 standard. A standard CMOS image sensor, receives the projected IR light and transfers the IR Light Coding image to the PS1080. The PS1080 processes the IR image and produces an accurate per-frame depth image of the scene.

The PrimeSensor includes two optional sensory input capabilities: color (RGB) image and audio (the PrimeSensor has two microphones and an interface to four external digital audio sources).

To produce more accurate sensory information, the PrimeSensor performs a process called Registration. The Registration process’s resulting images are pixel-aligned,which means that every pixel in the color image is aligned to a pixel in the depth image.

All sensory information (depth image, color image and audio) is transferred to the host via a USB2.0 interface, with complete timing alignment.

Microsoft announced at the Consumer Electronics Show in Las Vegas that Project Natal will be available during holiday 2010, though we have reason to believe that it may appear sometime in October.