[Xastir] Format for .geo files

[Tom Russo]

On Wed, Apr 20, 2022 at 11:55:27AM -0400, we recorded a bogon-computron collision of the <rufus.rizzo78 at gmail.com> flavor, containing:
> Thanks!  Yes I've done that and converted a few.  When I point Xastir to my
> Offline directory with the converted files, there are no maps.
> 
> The documentation reads like I need a type of index file.  I got the USGS
> csv indexes that match coordinates to the image files.  I'm looking for the
> needed formatting for that index file.  That's what I'm naively calling a
> .geo file.

No, there should be no need for an additional index file.

I have a whole directory of converted GeoPDFs in GeoTIFF format that work
exactly as well as the old USGS geotiff files that geopdf2gtiff.pl is meant
to emulate.

Is your Offline directory reindexed?  Does Xastir display an error messages
on the console?  Did you convert with geopdf2gtiff.pl?

And do you in fact have Xastir built to support geotiff files?

If you run "gdalinfo" on one of your converted files, what do you see?  It
should information about how the converted file is using WGS84 geographic
coordinates, and other information like the fact that it's using a color
table and not RGB.  For example:

Driver: GTiff/GeoTIFF
Files: NM_Escabosa_20110301_TM_geo.tif
Size is 3140, 3140
Coordinate System is:
GEOGCRS["WGS 84",
    DATUM["World Geodetic System 1984",
        ELLIPSOID["WGS 84",6378137,298.257223563,
            LENGTHUNIT["metre",1]]],
    PRIMEM["Greenwich",0,
        ANGLEUNIT["degree",0.0174532925199433]],
    CS[ellipsoidal,2],
        AXIS["geodetic latitude (Lat)",north,
            ORDER[1],
            ANGLEUNIT["degree",0.0174532925199433]],
        AXIS["geodetic longitude (Lon)",east,
            ORDER[2],
            ANGLEUNIT["degree",0.0174532925199433]],
    ID["EPSG",4326]]
Data axis to CRS axis mapping: 2,1
Origin = (-106.375000000000000,34.999999999999993)
Pixel Size = (0.000039808917197,-0.000039808917197)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (-106.3750000,  35.0000000) (106d22'30.00"W, 35d 0' 0.00"N)
Lower Left  (-106.3750000,  34.8750000) (106d22'30.00"W, 34d52'30.00"N)
Upper Right (-106.2500000,  35.0000000) (106d15' 0.00"W, 35d 0' 0.00"N)
Lower Right (-106.2500000,  34.8750000) (106d15' 0.00"W, 34d52'30.00"N)
Center      (-106.3125000,  34.9375000) (106d18'45.00"W, 34d56'15.00"N)
Band 1 Block=3140x2 Type=Byte, ColorInterp=Palette
  Color Table (RGB with 256 entries)
    0: 112,120,120,255
[...]


All that information in the geotiff is all that is needed to get Xastir to 
display it properly.

 

> On Wed, Apr 20, 2022, 11:10 Tom Russo <russo at bogodyn.org> wrote:
> 
> > ".geo" files are not for referencing geopdfs, they're for georeferencing
> > images in PNG or JPG format (like a scanned image or something).
> >
> > Geopdfs are newer than any map type coded into Xastir, and there is no
> > native support for them at all.
> >
> > You can, however, convert geopdfs to GeoTIFF format, and they'll work just
> > fine.
> > Since they have georeferencing information in the file already, you need no
> > other additional files to do this.
> >
> > However, you do have to convert the file using a script called "
> > geopdf2gtiff.pl"
> > in the Xastir "scripts" directory, and this script requires that you have
> > GDAL installed (it uses gdalinfo, gdalwarp, and the "rgb2pct.py" script
> > provided by GDAL).
> >
> >
> > On Wed, Apr 20, 2022 at 10:40:00AM -0400, we recorded a bogon-computron
> > collision of the <rufus.rizzo78 at gmail.com> flavor, containing:
> > > I'm working on getting USGS offline maps, and I'm having problems
> > bringing
> > > them up in Xastir.  Is there a format documented for the indexing of the
> > > maps?
> > >
> > > The link in the documentation is broken:
> > > http://data.geocomm.com/quadindex/
> > >
> > > I've got the USGS index files that point to the Geopdfs, and can convert
> > > them so they will work like the link mentions, but I'm unsure how to
> > format
> > > them.
> > >
> > > If I can get it working I can share my script.
> > >
> > > Thanks!
> > >
> > > Riley
> > > Kf4emz
> > > _______________________________________________
> > > Xastir mailing list
> > > Xastir at lists.xastir.org
> > > http://xastir.org/mailman/listinfo/xastir
> >
> > --
> > Tom Russo    KM5VY
> > Tijeras, NM
> >
> >  echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z]
> > [n-z][a-m]
> >
> > _______________________________________________
> > Xastir mailing list
> > Xastir at lists.xastir.org
> > http://xastir.org/mailman/listinfo/xastir
> >

-- 
Tom Russo    KM5VY
Tijeras, NM  

 echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m]