jpegs v/s jpegs?

How to differentiate between jpegs from scanned files and from digital camera?
(Of course there is tagging, meta info and all that.) Scenario: Lets say I saved my file as jpeg (scanned) with no meta data, same for digital camera file.

If there is no EXIF information there's really no way to tell for sure. You may be able to guess based on the general look (digital camera captures are generally cleaner when viewed at 100%) but that's about it.

Guy

In theory, I don't think there is going to be any difference. In practice, you'll be seeing grain in film if you look at it enlarged to 100%. Grain will tend have a slightly darker color than what is in its immediate neighborhood, and not appear to be completely random. Digital will either have nothing, or more noticeable and random color noise. Oversharpening seems will emphasize the difference.

Yes, if you start with a quality 4x5 or larger scan and reduce to a 600 by 750 pixel image size, and do the same with with just about any current high level digital SLR shot at ISO 100, telling the difference may well be impossible.

That may not help, but I think it is the best you are going to do.

I guess my way is too direct. My camera using one numbering system and my scanner uses another. I preserve those along with any titling I do.

For scanned film, I used the number I've assigned to the slide in my slide database program (a five digit number). For digital camera files, I use a numbering system based on capture date and camera file number.