Mercurial > hg > orthanc-stone
diff OrthancStone/Resources/Documentation/Coordinates.txt @ 1775:fca942f4b4a7
fix conversion from voxel centers to texture borders
author | Sebastien Jodogne <s.jodogne@gmail.com> |
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date | Wed, 12 May 2021 19:57:50 +0200 |
parents | |
children | 9ab251c03eda |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/OrthancStone/Resources/Documentation/Coordinates.txt Wed May 12 19:57:50 2021 +0200 @@ -0,0 +1,24 @@ + +Some notes about the coordinate systems +======================================= + +* The 3D coordinates are expressed in the PATIENT system, *not* the + "gantry" coordinates. As a consequence, the tags "Image Position + Patient" (0020,0032) and "Image Orientation Patient" (0020,0037) + describe the 3D geometry of a slice. + +* The tag "Patient Position" (0018,5100) could be used to convert from + patient coordinates to gantry coordinates, but this would be useful + to device manufacturers, whereas Stone primarly deals with users of + modalities. + +* The "Image Position Patient" gives the 3D coordinates of the CENTER + of the voxel of slice. + +* In 2D compositors, the origin of a texture corresponds to the CORNER + of the texture (*not* to the center of the first pixel). Roughly + speaking, the operation "floor()" must be applied to move from + floating coordinates to pixel coordinates. + +* The classes deriving from "IVolumeSlicer" must pay to attention to + convert from centers of 3D voxels to bounding boxes of 2D pixels.