# Volume Projection¶

This options allows to obtain, given a n already reconstructed volume, the corresponding projections.

Here a concise description of the related input parameters.

The following documentation has been extracted automatically from the comments found in the source code. Discard Parameters. object variable.

class Parameters_module.Parameters

The input variables are read from the input file. The input file is written with python syntax. The Input file is interpreted as python after a preprocessing The preprocessing was introduced at the time of HST-> PYHST transition to maintaing compatibility with:

• NO/YES meaning 0/1

• items containing FILE in their name can be initialized without using the “” which are otherwise necessary for strings

The input file has to set (some of) the following variables. To setup easily an input file you are suggested to start from one of the examples given in the doc.

PROJ_OUTPUT_FILE = 'v2p_%04d.edf'

When STEAM INVERTER=1 use this pattern to create projection file names. In this case the variable PROJ_OUTPUT_FILE determines where the projection are written.

PROJ_OUTPUT_RESTRAINED = 0

When the projected volume is smaller in heigth than the original projection, then the projection will be calculated when this option is active, with a size corresponding to the projected volume, not the original projection. As compensation more informations will be written in the images headers that can be used to localise the smaller projections inside the bigger ones.

STEAM_INVERTER = 0

When STEAM INVERTER=1 PyHST goes from volume to projections.