When I last got my Australian passport renewed, the guy in front of me had his photo rejected because it had been edited. They had some sort of automated analysis that I presume worked off spotting weird JPEG aliasing.
If there are signs it's edited, they'll tell you to come back with a different photo. (In this case, there was a photo shop a block away they had an arrangement with.)
Presumably that would only work if you hand over the digital photo. Converting it to analog (printing it) would lose all this data. You could then also rescan from the analog and receive a clear jpeg that should pass most tests depending on how good your scan was.
You submit physical photos, which Australia is insanely picky over. My most recent renewal took me three tries across three separate camera stores before I found pictures they were happy with.
The review process seems to be manual as far as I could tell, or at least it took O(days) each time for the results to come back.
If there are signs it's edited, they'll tell you to come back with a different photo. (In this case, there was a photo shop a block away they had an arrangement with.)