Raster background value isn't all 255s.

[martywilliams1]

I have a raster dataset that I'm trying to clip the background on. I've set the "display background value" to all 255s and it make some of the background disappear, but not all. When I clip on portions of the remaining background I get varying results like (248,249,247), (253,252,253), etc. I need to either change everything above 245 to 255 or change the background clipping so that the range it sees as background to a wider range.

Any help would be appreciated.

Thanks,

Marty

[DanPatterson_Retired]

Have you looked at the histograms in symbology? 

Do you have an image showing what you mean?  It could just be image variations for nodata or a white color

[DarrenWiens2 · Accepted solution]

You can add a mask raster function, where all values > 245 are interpreted as NoData: Mask function—ArcGIS Pro | ArcGIS Desktop 

[martywilliams1]

Darren,

That's exactly what I was looking for.  Thank you very much. I now have a clean aerial to work with.

Dan, If you want an image I can still upload one. I basically had a white band around my aerial. Some of it was (255,255,255), but most of it was less than that, but still white and should've been interpreted as "no data".

Thank you both very much.

Marty