Although I set the No Data areas in my grid to display as Transparent, when I bring them into MapInfo or ArcGIS they are not transparent.

A: This is because these GIS programs cannot read the transparency correctly.  If the images are pasted into other programs such as Powerpoint or Word the “No Data” areas will display as transparent.  The No Data colour must be set to transparency within the MapInfo program once the GeoTiff file is imported.  By default the no data cells are changed to white which may cause a problem if the colour stretch applied to the grid contains white for high values. In this instance we recommend making the “no data” colour one that is not used in the colour ramp, eg. black so that it can be selected in MapInfo and then made transparent without affecting any “real” data grid cells.

In ArcGIS it is possible for the transparent cells to be recognised in the raster image by going into the Layer Properties and setting the Alpha Channel to Band_4 under the Symbology tab.

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