[Xastir] GeoPDF

[Tom Russo]

On Sun, Sep 04, 2011 at 09:43:24PM -0400, we recorded a bogon-computron collision of the <lee.bengston at gmail.com> flavor, containing:
> However, when Xastir tries to read the converted files, it shows the
> following error in the terminal:
> 
> TIFFReadDirectory: Warning,
> /usr/share/xastir/maps/Offline/GeoTiff/VA_Manassas_20110606_TM.tif:
> unknown field with tag 42112 (0xa480) encountered.
> *** geoTIFF file
> /usr/share/xastir/maps/Offline/GeoTiff/VA_Manassas_20110606_TM.tif is
> not in the proper format:
> ***** Has 3 samples per pixel instead of 1
> *** Please reformat it and try again.
> 
> Is there a specific setting in gdal_translate that I need to use in
> order to convert the GeoPDF's in a way that Xastir will recognize?
> 

See README.MAPS, under the heading 
   XASTIR can only use GeoTIFF files that are 8-bit per pixel with one band

There is no option to gdalwarp or gdal_translate to create a one-band, 8-bit
color raster from a 3-band, 24-bit color raster.  You have to do it in
a separate step.  The instructions for doing that final step are in README.MAPS.

Some day it would be good to hack Xastir to deal with 24-bit rasters, but
that could be a challenge.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
 "One man alone can be pretty dumb sometimes, but for real bona fide
 stupidity, there ain't nothin' can beat teamwork." - Edward Abbey