A project that helps convert ERDAS HFA Annotation Layer (.ovr) to Shapefile(.shp)/GeoJSON(.geojson). To understand how ERDAS HFA file format works, I looked into how GDAL implements the conversion from ERDAS HFA Raster Format (.img) to .tif.
ERDAS also provided a detailed documentation explaining the internals of HFA structure. Although it details mainly on the raster .img format, .ovr follows the same file structure described in the documentation.
Details of setting up ovr2shp for development can be found here
gnuplot is used in the linux build to visualize the geometries/shape extracted from .ovr files. Gnuplot-Iostream Interface is used to interface with the gnuplot binary.
v0.1.0win-x86win-x64