Hi,<br>I am trying to convert a GIF image into a GeoTiff image. <br>Input GIF image information:<br>Projection: Polar Stereographic from North Pole, Cente meridian=97W, Height=0<br>Corners' Lower Left 19.9N 119.6W, Upper Right: 44.5N 59.5W<br>
<br>FWTools_2.0.6 commands used.<br>I used these commands to convert the map from GIF -> GeoTiff<br># Convert lat/lon corner points to X/Y points<br>cs2cs +proj=latlon +to +proj=stere +lat_0=90 +lon_0=-97 -r <<EOF >./pts_stere_xy.dat<br>
+46.4 -140.0 <br>+21.4 -79.0<br>EOF<br># Following points created by previous command cs2cs<br>ulx=-3484887.50<br>uly=-3737084.31 <br>lrx=2686546.21<br>lry=-8268339.04 <br><br>ifn=my_image.gif<br>ofn=US_SIGWX_LOWLVL_SFC-400_PIXEL.tif<br>
gdal_translate -of GTiff -co PROFILE=GeoTIFF -co INTERLEAVE=PIXEL -a_srs '<br>+proj=stere +lat_0=90 +lon_0=-97' -a_ullr $ulx $uly $lrx $lry $ifn $ofn<br><br>ISSUES:<br>The GeoTiff image obtained can be viewed using Openev but the lat/lon points don't look right(Used geodetic lat/lon preference to read lat/lon). I was not able to view the image using Udig.<br>
<br>Images uploaded:<br><br>GIF map: <a href="http://dl.dropbox.com/u/31095936/my_image.gif">http://dl.dropbox.com/u/31095936/my_image.gif</a><br><br>GeoTiff map: <a href="http://dl.dropbox.com/u/31095936/US_SIGWX_LOWLVL_SFC-400_PIXEL.tif">http://dl.dropbox.com/u/31095936/US_SIGWX_LOWLVL_SFC-400_PIXEL.tif</a><br>
<br><br>Q1: Could somebody let me know what I am doing wrong when creating the geotiff with wrong lat/lon points?<br>Q2: Does anyone know why I am not able to see it using Udig?<br><br>Thank you <br><br>