22. May 2013

Asus Xtion Pro Live – First Impressions

It is now a couple of years since affordable depth cameras have entered the market. Out of a developer’s perspective, the Asus Xtion Pro Live seemed to be better suited for development than the XBOX 360 Kinect. I still think so. Here are my first impressions gained when working with the Xtion in a university project.

The XBOX 360 Kinect was a crucial part of the hardware in both my bachelor’s thesis as well as in a later robotics project. During my thesis work, I worked with 3D data that was recorded from a Kinect camera on top of a Willow Garage P2. In the later robotics project, I had the pleasure to work altogether four XBOX 360 Kinects. Three of them were mounted on a Robotino, and the fourth one was used by our team for developing computer vision algorithms. While being very happy to work with so many depth cameras on one single platform, we had three big problems: First, it was not easy to arrange three Kinects on top of the robotic platform. Second, every single of the three Kinects required a separate power connection to a battery. Third, the stands of the Kinects were not very robust. These troubles forced us to disassemble the Kinects (following a tutorial on ifixit.com) in order to remove the stands and cutting the power supply cables in order to connect the cameras to the batteries.

The more expensive Asus Xtion Pro Live has a more solid stand, is easier to disassemble, and is powered only by USB (it does not have a motor like the XBOX 360 Kinect). It is also much smaller than the Kinect. In the retrospective, the Asus Xtion Pro Live should have been better suited for that particular robotics project. Having only one cable instead of two cables is also advantageous in other situations. It is easier to move teh camera around. As a friend pointed out to me, having no cable at all should be optimal. This requires a battery and a wireless channel for transferring the large data volume from the camera (someone done the maths?).

The specifications of the XBOX 360 Kinect and the Asus Xtion Pro Live are similar. After all, they are both built upon the PrimeSense depth sensor. Whether there are qualitative differences in certain aspects is something I am interested in finding out – future work. Asides from the XBOX 360 Kinect, there is also a more recent Windows Kinect variant that is to be taken into account when doing market research.