We ship two libraries:

1. libapriltag.so
   This is the main library that provides the main apriltag functionality. It
   exports ONLY apriltag_* and tag* symbols. Normal applications should use
   this library only

2. libapriltag-utils.so
   This library provides auxiliary functionality used primarily by the apriltag
   examples. It provides apriltag-specific functions for reading/writing images,
   processing commandline options and such. This library exports more symbols,
   many with very generic names. Most people won't need this library


The newer tag families (tagCircle49h12, tagStandard52h13, tagCustom48h12,
tagStandard41h12) need binary data to function, and upstream was shipping this
data inside their sources. This was resulting in very large source files that
took hours to build on some architectures, producing unacceptably high build
times:

  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=921256
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=920894

I resolve this by patching the sources to ship that data in separate binary
files to be read-in at runtime from /usr/share/apriltag

 -- Dima Kogan <dkogan@debian.org>, Sun,  3 Feb 2019 18:05:53 -0800
