How to correctly import a raster file with these metadatas into Tilemill?

Question

I have a GeoTIFF file for which gdalsrsinfo reports this:

PROJ.4 : '+proj=utm +zone=32 +datum=WGS84 +units=m +no_defs '

OGC WKT :
PROJCS["WGS 84 / UTM zone 32N",
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,
        AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4326"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",9],
PARAMETER["scale_factor",0.9996],
PARAMETER["false_easting",500000],
PARAMETER["false_northing",0],
UNIT["metre",1,
    AUTHORITY["EPSG","9001"]],
AXIS["Easting",EAST],
AXIS["Northing",NORTH],
AUTHORITY["EPSG","32632"]]

If I try to import that file into Tilemill, I cannot view it properly. If I chose to let Tilemill autodetect the SRS, it fails:

Unable to determine SRS for layer "antani2" at /home/strappanai/antani2.tiff

If in Tilemill I specify a Custom PROJ.4 string instead, that is, the one I get from gdalsrsinfo (and from QGIS as well), that is

+proj=utm +zone=32 +datum=WGS84 +units=m +no_defs

then the layer actually gets imported, but it is showed significantly tilted to the right - not as expected.

I don't know if this may matter to any extent, but QGIS imports and visualizes the file perfectly fine.

I also tried to reproject the source file as instructed here: https://www.mapbox.com/tilemill/docs/guides/reprojecting-geotiff/

But gdalwarp returns this error a thousand times and then fails:

ERROR 1: Too many points (441 out of 441) failed to transform,
unable to compute output bounds.
Warning 1: Unable to compute source region for output window     3593619,2225230,6394,6394, skipping.
More than 1000 errors or warnings have been reported. No more will be reported from now.

EDIT: This is the Layer Extent given by QGIS.

Layer Extent (layer original source projection) 638153.2011202700668946,5115644.8502587005496025 : 662908.4373886700486764,5132649.3878203006461263

Here's an identically behaving file: sample file

And here's how it's pictured in QGIS and in Tilemill (QGIS reads the SRS from the file, I specify the PROJ.4 string into Tilemill as stated above as it can't read it out from the TIFF).

Answer 1

I tested a bit with your example file. The solution was the following. I reprojected the file to WGS84 using QGIS and then added it to my Tilemill project defining the projection as WGS84.

The gdal command is as follows:

gdalwarp -overwrite -s_srs EPSG:32632 -t_srs EPSG:4326 -of GTiff antanired.tiff antanired_warp_WGS84.tiff

As you can see in the example it works with your provided data. But it failed leaving the settings on auto detect srs.

The tilting of the image to the right it only caused by srs differences. While the image is perfectly rectangular in UTM it will be a bit squeezed when it is shown in WGS84. The same will be true if you do it the other way around.

UPDATE

You might get rid of the black background by passing

nodata="0"

to the Advanced field during raster upload. As it is shown for Landsat data here

To give you the final answer to your question: The import is absolutely correct! Part of your error was the missing understanding of raster files and projections. I hope the trick with nodata definition works.