Hi Adam,
sure this is possible! There are two locations/ways to define NoData on a MosaicDataset:
OPTION 1: On the MosaicDataset Level in the Properties (General Tab, NoData Value Propertie) or/and
OPTION 2: as introduced when using the "Define MosaicDataset No Data" GP Tool. This will result in a "Mask" Process added to the individual rasters in your MosaicDatset.
In case of the setting in OPTION 1, all you have to do is edit the propertie
In case of OPTION 2 it gets a little bit more complicated, since I do not know for WHICH rasters you have defined NoData ... a selection, primary rasters BEFORE building overviews, ALL rasters including overviews ...
Lets start very general and come back to the solution a little later: If "NoData" does not show/produce clear and flawless results, it is because of your data. "Speckling" might be, because you have JPEG Images, where (intruduced by the lossy jpeg-compression) artifatcs are in your data. Try to use data (like uncompressed, TIFF-LZW-compressed, ...) where there is still a clear lossless definition of all content - define NoData there, then do whatever you want with it and always build the overviews AFTER you have defined no Data!
Now to your solution for OPTION 2: You need to select all rasters that have this Mask-process introduced by your NoData calculation, then use the "Batch Edit Raster Function" routine in the context menu of your MosaicDataset Footprint table (see description here) to remove the "Mask" function. And your done 🙂
Regards
Guenter
