EMgetOSM - EMsoft-org/EMsoft GitHub Wiki

Program: EMgetOSM

Dictionary indexing (DI) produces, among other things, a so-called Orientation Similarity Map, i.e., a map for which the intensity in each pixel measures how many of the top N matches that pixel has in common with its nearest neighbors. For a well annealed material, neighbouring pixels have very similar top match lists, so the OSM value will be high; near grain boundaries, one or more of the neighbors will have a completely different top match list, so the OSM value will be substantially smaller. As a result, Orientation Similarity maps generally show a clear outline of the microstructural components (grains, phases, voids, etc.).

During the DI run, the user sets the total number of top matches saved to the output file as well as the number of matches to be used for the OSM dataset. The EMgetOSM program provides a tool to extract a new OSM file from a dot product file for an arbitrary value of the number of top matches, N. The program uses a template file generated as follows:

EMgetOSM -t

and its content is as follows:

 &getOSM
! The line above must not be changed
!
! The values below are the default values for this program
!
! number of top matches to be used for OSM map (maximum of 5 different values, zero if not needed)
 nmatch = 20 0 0 0 0,
! input dot product file name
 dotproductfile = 'undefined',
! output tiff file name; prefix only !!!  .tiff will be added 
 tiffname = 'undefined',
 /

The entries are self-explanatory; up to five different values of N can be specified using the nmatch parameter, and each value will generate a different .tiff file.