[gdal-dev] gdalwarp on a file + world file - different limits

[Joaquim Luis]

Hi,

For the next version of GMT we have extended the ability of the ps2raster program
to take a postscript file generated by GMT either create a world file, or even further,
to call gdalwarp to create a true geotiff file.

Next is an example on how it will work

pscoast -JS-55/-60/15c -R-77/-55/-57.5/-48r -Df -Gred -P -Bg2 --BASEMAP_TYPE=plain --FRAME_PEN=0.1p > out.ps
ps2raster out.ps -Tt -W+ -V

(which executes this command)
gdalwarp -s_srs "+proj=stere +lat_0=-60 +lon_0=-55 +k=1 +x_0=0 +y_0=0 +a=6378137.000 +b=6356752.314245" out.tif out.tiff


But when I compare the gdalinfo output of the two files they do not agree.
Why are the LR coords from the geotiff file different from the tif + .tfw?
And where do they come from?

Thanks

Joaquim Luis

# ----------  THE .TFW CONTENTS
677.678633953751	# x_inc
0.0
0.0
-677.201365837256	# y_inc
-1389588.373683023000	# X-UL
1335922.909317081300	# Y-UL

# -------------------------------------------
# WHAT DOES GDALINFO SAY ABOUT THE .TIF + .TFW
gdalinfo out.tif
Upper Left  (-1389927.213, 1336261.510)
Lower Left  (-1389927.213,  329263.079)
Upper Right ( -188402.995, 1336261.510)
Lower Right ( -188402.995,  329263.079)

# -------------------------------------------
# WHAT DOES GDALINFO SAY ABOUT THE (GEO).TIFF
gdalinfo out.tiff
Upper Left  (-1389927.213, 1336261.510)
Lower Left  (-1389927.213,  329523.865)
Upper Right ( -188074.869, 1336261.510)
Lower Right ( -188074.869,  329523.865)