[Ros-kinect] Kinect camera info gives wrong value for marker tracking

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[Ros-kinect] Kinect camera info gives wrong value for marker tracking

Hey everyone

I have a bigger project going one and a part of that involves locating and tracking markers. I use ArToolKitPlus for this, downloaded from this page where further research is done, for ArToolKitPlus to work, then it needs the intrinsics parameters and to get those then I use the values specified by the /camera/rgb/camera_info, here I get the following message. 
  seq: 108
    secs: 1302552334
    nsecs: 20074974
  frame_id: /openni_rgb_optical_frame
height: 480
width: 640
distortion_model: plumb_bob
D: [0.0, 0.0, 0.0, 0.0, 0.0]
K: [525.0, 0.0, 319.5, 0.0, 525.0, 239.5, 0.0, 0.0, 1.0]
R: [1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0]
P: [525.0, 0.0, 319.5, 0.0, 0.0, 525.0, 239.5, 0.0, 0.0, 0.0, 1.0, 0.0]
binning_x: 0
binning_y: 0
  x_offset: 0
  y_offset: 0
  height: 0
  width: 0
  do_rectify: False
My problem is that when I use these parameters for the ArToolKitPlus library, then my marker detection is a bit off. It seems the vertical position is okay from a quick initial test, the horizontal is around is around 13cm off the center off the rgb sensor and the depth is 15-20cm off according to the front of the rgb sensor. 
The testing was just done using a measurement line and holding a marker by hand, so no values can be regarded as certain, but it is certain that the position of the marker is off and it all boils down to the camera parameters, but I do not know why. I hope someone has an idea to what is wrong


Sebastian Aslund

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