I have a DEM raster image in .img format. I am thinking about converting it (through Export Data in ArcMap) to the .tif format.

Will that change the quality or any pixel values?

  • 2
    If you'll create a tiff file that has the same bit depth and is either uncompressed or compressed with some lossless method (LZW, deflate, packbits...) the quality will not change. – user30184 Mar 7 '18 at 20:31
  • 3
    The lossy method for GeoTIFF is JPEG which doesn't apply to 32bit float data types so, no, you won't loose any quality provided you don't change the cell size or use a renderer but the question is why? What does TIFF do that ERDAS IMG format doesn't? If you must change the format I wouldn't use Export Data I would use Raster to Other Format or Copy Raster geoprocessing tools; not that Export Data has any problems but I wouldn't lock up an ArcMap session for something that can be done equally as well in ArcCatalog - unless you need to use the advanced options in the exporter. – Michael Stimson Mar 7 '18 at 21:39
  • What happens when you try to do this on a test image (or your real one, if it is small enough to be used for its own test)? – PolyGeo Mar 11 '18 at 22:04