[Xastir] Geo Files

[Lee Bengston]

I'm looking at a sample geo file for a map in the UK that's in JPG format.

FILENAME     1liv-man.jpg
#             x       y        lon           lat
TIEPOINT       0      0      -3.51500       53.68800
TIEPOINT     1740    875     -1.61100       53.11700
IMAGESIZE    1740    875
REFRESH      250

What is the refresh parameter?

I've never actually tried making a geo for a basic map like a PNG or JPG.
Just to be sure, is it safe to assume tiepoint x,y=0,0 is the lower left
and (given the image size), 1749,875 is the upper right?

Thx,
Lee - K5DAT