thx Even for explanation. Also I see the real important for some software is the presence of this section:
Keyed_Information: GTRasterTypeGeoKey (Short,1): RasterPixelIsPoint End_Of_Keys. It can have two possibl values: RasterPixelIsPoint or RasterPixelIsArea Seem that without a value for GTRasterTypeGeoKey some software don't work. Is possible configure gdal to add this values when converting a tif+tfw to a geotiff ? Andrea. 2014-08-03 10:49 GMT+02:00 Even Rouault <even.roua...@mines-paris.org>: > Le samedi 02 août 2014 23:48:54, Andrea Peri a écrit : >> Hi, >> >> I have transform many old tiff+tfw rasters using this gdal transformation: >> >> gdal_translate -ot Byte -of GTiff -b 1 -a_nodata none -stats -co >> COMPRESS=NONE -co INTERLEAVE=PIXEL -co PROFILE=GDALGeoTIFF -co >> TILED=YES -co BLOCKXSIZE=256 -co BLOCKYSIZE=256 -co SPARSE_OK=TRUE -co >> TFW=NO filein.tif fileout.tif >> >> They are wrking correctly with qgis and with mapserver for several months. >> >> Now I need to use this geotiffs with another program. >> But this program say that these images are not realy GeoTiffs. >> >> I test them using listgeos and have this result: >> >> TIFFReadDirectory: Warning, Unknown field with tag 42112 (0xa480) >> encountered. Geotiff_Information: >> Version: 1 >> Key_Revision: 1.0 >> Tagged_Information: >> ModelTiepointTag (2,3): >> 0 0 0 >> 559417.445637 4927786.430528 0 >> ModelPixelScaleTag (1,3): >> 0.5 0.5 0 >> End_Of_Tags. >> Keyed_Information: >> End_Of_Keys. >> End_Of_Geotiff. >> >> Some people say me that this is not a true geotiff because are missing >> several tags. >> I reported a supposed response from a real geotiff: >> >> Geotiff_Information: >> Version: 1 >> Key_Revision: 1.0 >> Tagged_Information: >> ModelTiepointTag (2,3): >> 0 0 0 >> 673347 4298291 0 >> ModelPixelScaleTag (1,3): >> 1 1 1 >> End_Of_Tags. >> Keyed_Information: >> GTModelTypeGeoKey (Short,1): ModelTypeProjected >> GTRasterTypeGeoKey (Short,1): RasterPixelIsArea >> GTCitationGeoKey (Ascii,37): "NAIP 2012 >> m_3808409_sw_16_1_20120607" >> ProjectedCSTypeGeoKey (Short,1): PCS_NAD83_UTM_zone_16N >> PCSCitationGeoKey (Ascii,21): "NAD83 / UTM zone 16N" >> ProjLinearUnitsGeoKey (Short,1): Linear_Meter >> End_Of_Keys. >> End_Of_Geotiff. >> >> PCS = 26916 (NAD83 / UTM zone 16N) >> Projection = 16016 (UTM zone 16N) >> Projection Method: CT_TransverseMercator >> ProjNatOriginLatGeoKey: 0.000000 ( 0d 0' 0.00"N) >> ProjNatOriginLongGeoKey: -87.000000 ( 87d 0' 0.00"W) >> ProjScaleAtNatOriginGeoKey: 0.999600 >> ProjFalseEastingGeoKey: 500000.000000 m >> ProjFalseNorthingGeoKey: 0.000000 m >> GCS: 4269/NAD83 >> Datum: 6269/North American Datum 1983 >> Ellipsoid: 7019/GRS 1980 (6378137.00,6356752.31) >> Prime Meridian: 8901/Greenwich (0.000000/ 0d 0' 0.00"E) >> Projection Linear Units: 9001/metre (1.000000m) >> >> Corner Coordinates: >> Upper Left ( 673347.000, 4298291.000) ( 85d 0'12.06"W, >> 38d48'58.87"N) >> Lower Left ( 673347.000, 4290632.000) ( 85d 0'18.99"W, >> 38d44'50.54"N) >> Upper Right ( 679532.000, 4298291.000) ( 84d55'55.75"W, >> 38d48'54.41"N) >> Lower Right ( 679532.000, 4290632.000) ( 84d56' 2.92"W, >> 38d44'46.10"N) >> Center ( 676439.500, 4294461.500) ( 84d58' 7.43"W, >> 38d46'52.50"N) >> >> ----- >> >> I'm a bit confused. >> Because I have produced my GeoTiffs using gdal. And if it fail to >> produce a real geotiff I have a trouble. >> >> So the main question is a geotiff ith only the tags reported a real geotiff >> ? > > Andrea, > > The difference between the 2 geotiff is that the first one does not have > information on the spatial reference system, but only the geotransform that > comes from the .tfw file. > Skimming quickly through the GeoTIFF specification ( > http://www.remotesensing.org/geotiff/spec/contents.html ) doesn't immediately > show if it is valid or not, although it would be best if readers are robust to > missing information. > If you know the SRS of the maps, you can try adding -a_srs EPSG:XXXX or -a_srs > wkt_string. > You could also try -a_srs "LOCAL_CS[\"Unknown\"]" if you don't know the SRS at > all. This will write a few geotiff keys to define a unknown CRS, but it is not > obvious that your reader will like it. > > Even > > -- > Geospatial professional services > http://even.rouault.free.fr/services.html -- ----------------- Andrea Peri . . . . . . . . . qwerty àèìòù ----------------- _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev