Say you have 2 files.
One called Image_259.jpg
and the other called Picture_12.jpg
Now both files are a picture of the SAME exact thing.
Matter of fact it is the SAME picture just put on there twice.......it was copied around, or it was downloaded twice....got copied and renamed.....maybe it was slighty edited and then resaved (which makes a copy in a diff name)
Now the problem is that the duplicate file finder will NOT knwo its the same picture......it only looks at the file name.....and its different....not duplicate.......so its not flagged, and therefore not removed. Leaving a duplicate image.
Thats the inherent problem
So, you would have to do a couple different things.
First do a file duplicator search, and remove duplicates.
THEN, run an image duplicate search......and that can take a LONG time with SO MANY images to go through.
As the image duplicate search is much more indepth, and uses a LOT or CPU power.