# Depth distance Kinect v2

• ### General discussion

• Hi,

I have a doubt.
The distance / depth of a point (joint) from kinect v2 is given by the straight line joining the camera and point (in image A) or the distance between the camera and the floor of the point (in image B)?

I attach a picture to simplify :)

Monday, January 19, 2015 12:59 PM

### All replies

• Are you taking into account the height/width, focal length and the projecting the world into the camera plane(depthframe)?

Carmine Sirignano - MSFT

Monday, January 19, 2015 6:20 PM
• Are you taking into account the height/width, focal length and the projecting the world into the camera plane(depthframe)?

Carmine Sirignano - MSFT

I m talking about the effective distance (depth) of an object.
In particular about the Joints of the body.
I have a Joint (x,y,z) where z is the depth in mm.
So what about the "depth" ( of the head joint for example):

(i) is it the in-air lenght between camera and joints [red line in the figure below] ? or (ii)  the distance from the camera to the joints plane [green line in the figure below]?

NB: Green line is perpendicular with the white panel (joints plane).

I have another question: since the two people are on the same plane, is the z coordinate the same for both?

Thank you very much for your collaboration!

Tuesday, January 20, 2015 8:41 AM
• Hi,
Joint exposes a Position property of type CameraSpacePoint where Z grows out in the direction the sensor is facing
If we are talking about DepthFrame, data coming back from depth is the distance in mm from the focal plane. Imagine the sensor as a plane not as a point, to clarify: if you point your sensor to a wall each point will have the same distance.

Hth
-g

@Carmine: Hello! nice to see you!

Gian Paolo Santopaolo - softwarelab.it - thedarksideof.net
Disclaimer: This post is provided "AS IS" with no warranties, and confer no rights.

Tuesday, January 20, 2015 10:36 AM