Mercurial > hg > orthanc-stone
view 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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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.