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Skeleton Min and Max X RRS feed

  • Question

  • When reading over http://channel9.msdn.com/Series/KinectSDKQuickstarts/Skeletal-Tracking-Fundamentals, it indicates that the min and max X positions will be in the range -1 to 1. Based on my testing in looking at the joint position data, the min does seem to be around -1 (more like .9), but the max has gone just above 2.0. The SDK documentation doesn't say (at least not on Vector.X member). 

     

    Can someone clarify if the channel 9 article is incorrect and what the official ranges are? I can certainly go with the values I'm seeing but I'd like to be sure.

    Saturday, June 25, 2011 4:19 PM

Answers

  • There is no official tight bound (i.e., as opposed to double.MinValue and double.MaxValue) for X and Y coordinates in skeletal space (described in pages 22-23 of programming guide: http://research.microsoft.com/en-us/um/redmond/projects/kinectsdk/docs/ProgrammingGuide_KinectSDK.pdf), but the fact that the depth camera doesn't perceive anything beyond 4m caps the Z coordinate at 4.0, and then given the camera field of view I wouldn't expect anything beyond -3 or +3 for people standing 4 meters from camera, but these are just numbers obtained from practical use of camera. I will follow up to see if we can provide official bounds in the future.

    Hope this helps!
    Eddy


    I'm here to help
    Wednesday, June 29, 2011 12:53 AM

All replies

  • thnk2wn,

    Just tested a skeleton tracking app I have.  I'm definitely able to go over 1, but it does tend to hover between -1 and 1 most of the time.

    James


    James Ashley - Presentation Layer Architect at Razorfish Emerging Experiences
    jamesashley@imaginativeuniversal.com
    www.imaginativeuniversal.com www.emergingexperiences.com
    Sunday, June 26, 2011 5:30 PM
  • Thanks James. That is behavior I see as well. I have to determine the max area and 1 didn't seem to be it but probably wouldn't hurt much to use 1 as Max X.

     

    Enjoyed your CodeStock Kinect talk by the way

     

    Geoff

    Sunday, June 26, 2011 5:37 PM
  • There is no official tight bound (i.e., as opposed to double.MinValue and double.MaxValue) for X and Y coordinates in skeletal space (described in pages 22-23 of programming guide: http://research.microsoft.com/en-us/um/redmond/projects/kinectsdk/docs/ProgrammingGuide_KinectSDK.pdf), but the fact that the depth camera doesn't perceive anything beyond 4m caps the Z coordinate at 4.0, and then given the camera field of view I wouldn't expect anything beyond -3 or +3 for people standing 4 meters from camera, but these are just numbers obtained from practical use of camera. I will follow up to see if we can provide official bounds in the future.

    Hope this helps!
    Eddy


    I'm here to help
    Wednesday, June 29, 2011 12:53 AM