Fail to detect scan of print and scan of negative as duplicates

[Rayden]

I have some photos that are scanned colour negatives and some scanned colour prints. The images (both positive) are virtually identical except in some cases the colour is a bit different, for example one might be darker than the other. I can not get Duplicate Cleaner Pro 4.1.4 for detect that these are the same or even a loosely similar image. Is there a setting or option that I could use that would help me with this?

I have loads of folders of images scanned over the years and I want to sort them out.

[DigitalVolcano]

Are they cropped identically? It may not match if they are too different in cropping and alignment. You can submit a couple of examples to support if you like and we'll take a look.