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. Author manuscript; available in PMC: 2008 Dec 10.

Published in final edited form as: IEEE Trans Nucl Sci. 2005 Oct;52(5 I):1288–1294. doi: 10.1109/TNS.2005.858208

The geometry of a stereo acquisition with the coordinate systems. (xⁱ,yⁱ) and (x^j, y^j) are the coordinates in images “i” and “j” of the markers corresponding to 3D point located at (x^w, y^w, z^w) in the SPECT or Polaris coordinate system. The origin of the SPECT coordinate system is a corner of the stack of reconstructed SPECT slices. Geometrically, the point X^w is the intersection of the lines passing through the optical centers Cⁱ and C^j of the cameras and the points Xⁱ and X^j respectively.

The two columns represent images acquired from each of a stereo pair of cameras. The top row (A and B) are pictures of our calibration phantom laying on the bed of our SPECT system with room lights on. The second row (C and D) shows the visibility of the spheres of the calibration phantom with room lights off. The third row (E and F) shows stereo images acquired with room lights on a volunteer laying in imaging position on the bed of the SPECT system wearing a garment made up of four rows of four spheres each. The last row (G and H) is the same as E and F except the room lights have been turned off. Notice that the spheres are easily visible regardless of room lighting.

The geometry of a stereo acquisition with the coordinate systems. (xⁱ,yⁱ) and (x^j, y^j) are the coordinates in images “i” and “j” of the markers corresponding to 3D point located at (x^w, y^w, z^w) in the SPECT or Polaris coordinate system. The origin of the SPECT coordinate system is a corner of the stack of reconstructed SPECT slices. Geometrically, the point X^w is the intersection of the lines passing through the optical centers Cⁱ and C^j of the cameras and the points Xⁱ and X^j respectively.

The two columns represent images acquired from each of a stereo pair of cameras. The top row (A and B) are pictures of our calibration phantom laying on the bed of our SPECT system with room lights on. The second row (C and D) shows the visibility of the spheres of the calibration phantom with room lights off. The third row (E and F) shows stereo images acquired with room lights on a volunteer laying in imaging position on the bed of the SPECT system wearing a garment made up of four rows of four spheres each. The last row (G and H) is the same as E and F except the room lights have been turned off. Notice that the spheres are easily visible regardless of room lighting.