[Xastir] Geo Files

[Tom Russo]

On Mon, Dec 14, 2015 at 09:08:07PM -0500, we recorded a bogon-computron collision of the <lee.bengston at gmail.com> flavor, containing:
> 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?

Actually, 0,0 is the upper left, 1740,875 is the lower right.

That's coz in the file, the upper left is the first pixel stored, and the 
lower right is the last.

REFRESH is supposed to be for dynamic images, and is the time in seconds between
redraws of the image.  Thing radar imagery, etc., that gets downloaded often,
and needs to be redrawn.

It does not make sense to have this non-zero for a static file.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
 echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m]