Why does the alpha channel turn the entire mosaic transparent?

Question

Hello,

I am trying to create a mosaic from a number of geotiff images. By default, transparent areas are black. If I select band_4 for the alpha channel in symbology, the entire mosaic disappears.

I have tried creating the mosaic with Mosaic To New Raster, and Create Raster Dataset then Add Raster To Mosaic. Both workflows have the same problem.

If I drag and drop a raster onto the map, it works great. The alpha channel uses band_4 by default and the rest of the image is visible.

Is there an ArcPy equivalent to drag and drop? If so, can that be added to a mosaic? Are there other ways to create mosaics that handle transparency better? Am I missing a step that is causing the transparency problem?

Ultimately this needs to be automated. Any help is appreciated.

Thanks!

mosaic_no_alpha.PNG

mosaic_with_alpha.PNG

CodyBenkelman_3-1715373522992.png

CodyBenkelman_4-1715373522992.png

JesseTemplin2 · Accepted Answer

The solution was to enable "display background value" under the mask tab in symbology, while leaving the alpha channel set to none.