# Origin coordinate system

• ### Question

• Hello,

can I ask you to explain me where precisely the origin of coordinate system is? Especially its X and Z coordinates...

X) The length of Kinect is 25 cm... which is the point where the origin is? I thought it's on about 12.7 cm, but in your documentation it seems to be on about 8 cm...

Z) The profundity of the kinect is about 6.7 cm... is the origin of the coordinate system where I indicated 0 cm?

Thanks and regards.

Tuesday, February 10, 2015 11:02 AM

### All replies

• There are different coordinate spaces centred on the RGB or IR camera centre. As for how these align to the exterior case of the Kinect could vary slightly from unit to unit, so it would be difficult to precisely know where they are on your Kinect. Why do you need to know?
Tuesday, February 10, 2015 12:00 PM
• I need to know the origin of the IR camera; this because in my application I use the Kinect to move an avatar in a 3D space. In order to place correctly the avatar in the 3D scene I need to know where precisely the user is respect to the IR camera, or better, respect to the origin of space of IR camera.

I understand that this origin can slightly change, but surely exists a default position, and a maximum error tolerance...

Tuesday, February 10, 2015 1:12 PM
• Have you looked at something like this? http://pterneas.com/2014/05/06/understanding-kinect-coordinate-mapping/

It gives a nice overview on body space points and how they are mapped to colour or depth (IR) space. I have not done much with body points, so perhaps someone else is better suited to answer avatar type questions. But I don't know that knowing the exact position of the IR origin in relation to the case is important for you. Do you want to be able to tell where the Kinect is in relation to the physical world, for example the room that you are in? For this you could use KinectFusion, as it gives you the position of the Kinect (and therefore IR space) in relation to the world.

Tuesday, February 10, 2015 1:56 PM
• for IR/Depth the 0,0 is the center of the depth/ir camera not the center of the device.

Carmine Sirignano - MSFT

Wednesday, February 11, 2015 6:53 PM
• Does anyone know where the center of the IR camera is? Do I need to break one open and measure myself?
Thursday, June 1, 2017 1:48 AM