Mercurial > hg > orthanc-stone
view OrthancStone/Resources/Documentation/Coordinates.txt @ 1779:9ab251c03eda
unit test VolumeRendering.TextureCorners
author | Sebastien Jodogne <s.jodogne@gmail.com> |
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date | Fri, 14 May 2021 10:01:20 +0200 |
parents | fca942f4b4a7 |
children | 20a0aba0ede5 |
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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 top-left voxel of slice. * In 2D compositors, the origin of a texture corresponds to the CORNER of the top-left pixel of the texture (*not* to the center of this pixel). Roughly speaking, the operation "floor()" must be applied to move from canvas coordinates (floating-point numbers) to pixel coordinates in the image buffer (integer numbers). * The classes deriving from "IVolumeSlicer" must pay to attention to convert from centers of 3D voxels to bounding boxes of 2D pixels.