Name: marker_gen - generate marker bitmaps from marker input list

 Type: mapper

 Author: Ian Curington, AVS/UNIRAS Ltd.

 Description:
   This module converts vector edge defined marker shapes
   into ROI bit masks coverage for AVS images.
   The input is compatable with any AVS image, and
   any fully specified marker list 1D integer field.
   The marker list can be specified from a stored field,
   or more often, marker_select, or marker_pick modules.

   This module scan converts the marker edge list into
   a binary bit pattern, where the bit pattern at each
   pixel is either zero for no marker present, or the
   marker shape index.

   The output is a full size scalar byte field, the same
   size as the input image.