Hello Mark,
Yes this can be achieved. I have utilised raster functions to do this. Usually the alpha channel is 0 & 255.
So what you do is as follows:
- Use the raster function to Extract the Alphas channel from the image (Extract Bands)
- This will give you a single band image of 0 & 255
- Then use the GP tool Raster to Polygon.
- This will give you a vector layer of the image boundary and the image content.
- You can then filter the vector layer by either of the values.
Hopefully this is what you are after. You can even use this shape to replace the footprints in a Mosaic dataset
Cheers
Gordon