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I have quite a number of huge TIFF files, each TIFF file has a TFW file associated. gdalinfo shows that the TIFF files are not real GeoTIFF (no embedded data). I know the TIFF's are in WGS84, UTM format. I was able some time ago to load these files into CompeGPS, which created properly calibrated images in that software.

Now I need them converted to MBTILES to use with AlpineQuest on Android. I can create the mbtiles with this command:

gdal_translate test.tif test.mbtiles -of MBTILES

The problem is that the map is not correctly calibrated!

It should sit around 45N/7E, but if I open the MBTILES in QGis or in AlpineQuest I see it around 40N/1E.

I suspect the problem is with the source image, since also the TIFF+TFW will create a similarly misplaced image in QGis.

Now I am quite an amateur in GIS matters, so I am puzzled and really don't understand what I am doing wrong or what I should be actually doing?

Can somebody help me undestand what I am doing wrong?

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You need to tell gdal_translate what projection your input/output data is in (since it can't work it out as there are no .prj files. To do this you use the -a_srs option with the EPSG code of your data.

You can use epsg.io to look up the EPSG code if you don't know it.

  • Yes! That was it. The difficult part for me was find the right code, since i had no precise idea. It turns out it is the EPSG:7791! – WillyGardiol Jul 16 '18 at 14:28

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