RTK/Meetings/TrainingNov15: Difference between revisions

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There are as many projections as described in the geometry.xml file. You can edit the geometry.xml file, remove all projections except one, and try again. Such a modified geometry.xml file is already provided along with the data (singleProjectionGeometry.xml). Run the following command line
There are as many projections as described in the geometry.xml file. You can edit the geometry.xml file, remove all projections except one, and try again. Such a modified geometry.xml file is already provided along with the data (singleProjectionGeometry.xml). Run the following command line


rtkforwardprojections -i muCT.mha -o singleProjection.mha -g singleProjectionGeometry.xml
  rtkforwardprojections -i muCT.mha -o singleProjection.mha -g singleProjectionGeometry.xml


You can check with vv that the file contains only one projection
You can check with vv that the file contains only one projection


vv singleProjection.mha
  vv singleProjection.mha


== Back projection ==
== Back projection ==

Revision as of 04:53, 26 October 2015

Here is a list of the RTK command lines you will have to run during the training, along with the data you will need. To start, download the following data and extract it in a folder of your choice : LINKTODATA


Forward projection

To forward project the CT.mha volume, following the geometry described in geom.xml, run

 rtkforwardprojections -i muCT.mha -o projections.mha -g geometry.xml

Look at the result using vv

 vv projections.mha

There are as many projections as described in the geometry.xml file. You can edit the geometry.xml file, remove all projections except one, and try again. Such a modified geometry.xml file is already provided along with the data (singleProjectionGeometry.xml). Run the following command line

 rtkforwardprojections -i muCT.mha -o singleProjection.mha -g singleProjectionGeometry.xml

You can check with vv that the file contains only one projection

 vv singleProjection.mha

Back projection

Start by back projecting a single projection. Run

rtkbackprojections -p . -r singleProjection.mha -o singleBackProjection.mha -g singleProjectionGeometry.xml

Observe the result with vv

vv singleBackProjection.mha

As you can see, the projection data seems to be smeared into the volume. Now back project all projections, by running

rtkbackprojections -p . -r projections.mha -o backProjection.mha -g geometry.xml

Look at the result with vv. In order to compare it with the original image, run

vv backProjection.mha muCT.mha --linkall

Click in one of the display windows, hit 'Ctrl + G' to center the view on the tumor. Hit 'w' to automatically compute reasonable window and level values. You can navigate between "muCT.mha" and "backProjection.mha" by hitting the 'Tab' key.