topgm.c ... truncate lower 2 bits and make pgm file
geosgame.c ... use GEOS algorithm to make geo-coded pgm image file
game.py ... drive C programs (untar / extract parameters etc)

usage:
make topgm
make geosgame
edit game.py to properly set SRCDIRBASE
python game.py YYYYmmddHH

Note that if you set argument as 2006112811, game.py search for 
200611281032 data according as JMA convention.

See also:
http://www.jma.go.jp/jma/jma-eng/satellite/mtsat1r/4.2HRIT_1.pdf
http://www.eumetsat.int/Home/Main/Publications/CGMS_Publications/General_CGMS_Documents/groups/cps/documents/document/pdf_cgms_03.pdf

