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Re: tag for edited file

Cross-posted to 3 groups.

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On 17/07/2020 22:21, dale wrote:
> What about a tag in an image file indicating it is not the original?

Utterly pointless. Anyone that understands the file formats can tell if 
something has been through one of the common image editing programs and 
many cameras include enough meta information and use custom quantisation 
tables in their JPEGs to effectively have signed the original image.

You cannot stop someone producing a convincing edited fake that looks 
entirely authentic using already existing tools.
> 
> Taking it further, what about including each edited image in the file?

If you want the file size to grow exponentially then why not?

Strangely NASA have a bug in their workflow that means sometimes they 
publish images which contain two or three identical thumbnails with a 
brace of original images concatenated. Unclear how or why they do it.

Mickeysoft Word does that sometimes to corporate documents where users 
drag and drop images into report templates originally written in a 
legacy version. The document grows exponentially in size each time it is 
edited with different versions of Word as more and more orphaned image 
data accumulates in the file with each iteration.

-- 
Regards,
Martin Brown

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tag for edited file dale <dale@dalekelly.org> - 2020-07-17 17:21 -0400
  Re: tag for edited file "Carlos E.R." <robin_listas@es.invalid> - 2020-07-18 00:45 +0200
    Re: tag for edited file nospam <nospam@nospam.invalid> - 2020-07-18 11:37 -0400
      Re: tag for edited file "Carlos E.R." <robin_listas@es.invalid> - 2020-07-21 15:03 +0200
        Re: tag for edited file nospam <nospam@nospam.invalid> - 2020-07-21 10:13 -0400
          Re: tag for edited file "Carlos E.R." <robin_listas@es.invalid> - 2020-07-21 21:33 +0200
            Re: tag for edited file nospam <nospam@nospam.invalid> - 2020-07-21 18:45 -0400
  Re: tag for edited file Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2020-07-18 16:34 +0100
  Re: tag for edited file dale <dale@dalekelly.org> - 2020-07-23 15:54 -0400
    Re: tag for edited file nospam <nospam@nospam.invalid> - 2020-07-23 16:04 -0400

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