GTIFGetProj4Defn (and listgeo.exe) : incomplete proj4 string for Proj4 (version>=4.6)

[giorgiomugnaini]

The function GTIFGetProj4Defn in geo_normalize.h/geotiff_proj4.c is not able to produce a complete and correct proj4 string.

In particular the lack of suitable code producing "+datum" is manifest examining the code.

Parameter "+datum" is mandatory for Proj version > 4.6 in case of pj_transform() requiring datum shifts. So such function cannot be fruitfully employed with pj_init().

I.e., for an UTM33 tiff the incomplete proj4 string :

+proj=utm +zone=33 +ellps=WGS84 +units=m

will be produced, whereas the correct string should be:

+proj=utm +zone=33 +ellps=WGS84 +datum=WGS84 +units=m