I started out trying to merge some geotiff topo maps of a state. I kept getting results that were all black. It seems that style was palletee unique values and that merge could not handle that. So I converted them to multiband color using gdal_translate. Some of the merged topos were not lining up next to each other as they should. It seems that they were on the edge of a UTM region, each one in a different one. So I decided to convert them to WGS84 latitude and longitude. I can partially do that but when I display the files the coordinates seem to be in utm instead of latitude and longitude. Here is info on one such file:
Original out2 Name out2 Source /tmp/out2.tif Provider gdal CRS EPSG:4326 - WGS 84 - Geographic Extent 212740.2107839999953285,3630863.9934609998017550 : 413984.4187070000916719,3772545.1990390000864863 Unit degrees Width 7923 Height 5578 Data type Byte - Eight bit unsigned integer GDAL Driver Description GTiff GDAL Driver Metadata GeoTIFF Dataset Description /tmp/out2.tif Compression Band 1 STATISTICS_MAXIMUM=255 STATISTICS_MEAN=238.21578824081 STATISTICS_MINIMUM=131 STATISTICS_STDDEV=37.09178797644 More information AREA_OR_POINT=Area TIFFTAG_DATETIME=1996:10:29 16:21:10 TIFFTAG_IMAGEDESCRIPTION=USGS GeoTIFF DRG 1:250000 Quad of Tularosa. Product:487866 TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch) TIFFTAG_SOFTWARE=USGS CD Archiver program tif2usgsdrg v.1.0 TIFFTAG_XRESOLUTION=250 TIFFTAG_YRESOLUTION=250 Dimensions X: 7923 Y: 5578 Bands: 1 Origin 212740,3.77255e+6 Pixel Size 25.4,-25.4 Its coordinates are EPSG:4326, but they display as UTM and not latitude and longitude. It is as if the pixel data coordinates were not converted but everthing else one. I have tried gdaltransform and gdal_translate. So how do I do this? Maybe I am forgetting a parameter. Here is what I ran on the command line after the gui did not work: gdal_translate -a_nodata 0.0 -ot Byte -a_srs "EPSG:4326" -expand rgba -of GTiff /srv/data/nm_topo/scale_250k/c33106a1.tif /tmp/out2.tif gdalwarp -ot Byte -s_srs "EPSG:4267" -t_srs "EPSG:4326" -of GTiff /srv/data/nm_topo/scale_250k/c33106a1.tif /tmp/out2.tif I am using the latest version of qgis. If I try to use -expand in the processing gui for translate it says that it is an invalid parameter. It works on the command line though. _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
