I have a TIF Image in EPSG:31467 and need to reproject it to EPSG:25832 and convert to ECW format. I have to do this with FME2017 as ESRI does not write to ECW without the ECW licence. After transforming, I then load the image into ArcGIS 10.3.1 and see that the resulting image gets the coordinatensystem EPSG: 2632 (NUTM32) assigned to it. Where does this NUTM32 System come from?  If I do the same with a SHP from 31467 to 25832 it works fine and shows the right coordinatsystem in ArcGIS.

Why does this work differently for images?