Unmodifiable Image Format - is there such a thing?

Discussion in 'Digital Photography' started by August, Sep 12, 2003.

  1. August

    August Guest

    Is there such a format for images that is equivalent to a .PDF? We
    would like to switch to digital photography for our chain-of-custody
    photographs but our SOP states that the negatives (digital or not)
    cannot be modified in any way- view and view only such as conventional
    chemical photography negatives. Unfortunately, case-by-case, we only
    process a dozen, or two at most, images so it is not cost effective to
    burn each session to a CD-R. We need a way to store them in a "safe"
    format until enough are gathered to burn them.
    Any ideas?
    If possible, please respond off-group to

    Thanks so much,
    August, Sep 12, 2003
    1. Advertisements

  2. August

    JackD Guest

    With CD-R available for something like $0.30 a disk that works out to less
    than 2 cents an image given the number of images you are taking about. It
    would cost more in labor to create the file and then later burn it to CD
    than it would to just burn to CD to begin with.

    JackD, Sep 12, 2003
    1. Advertisements

  3. CDR in bulk are like a dime a piece. That's too expensive?
    Andrew McDonald, Sep 12, 2003
  4. August

    Ed Ruf Guest

    Hate to tell you that this view of PDF is sadly uninformed. PDF protection
    is a joke propagated by Adobe. Ghostscript and other freely and widely
    available tools can be used to defeat Adobe's "protection" in a matter of
    No, you ask a question on usenet, you get a reply on usenet. Don't want
    that, then don't come here.
    Ed Ruf Lifetime AMA# 344007 ()
    See images taken with my CP-990 and 5700 at
    Ed Ruf, Sep 12, 2003
  5. Watermarking might give you some sort of protection, but if you're worried
    about the costs of cd-rs, no point even looking into if it could serve that

    Oh, wait, what about those strange cd-rW things?

    Honestly, you're pinching the wrong pennies if the process needs to be
    Jason O'Rourke, Sep 12, 2003
  6. August

    Adam R Guest

    Use PGP to apply a digital signature to the JPEGs. Then when it comes time
    to present them as evidence, re-verify the signature.

    So long as the security of the signing key is not compromised, you have no
    problem. For additional defence-lawyer-proofness, you could sign with
    multiple keys, with separate individuals responsible for the keys.


    ps agree with the sentiment: Ask a question on usenet, get a reply on
    usenet. This is a non-commercial, non-proprietary forum with the goal of
    sharing knowledge.
    end of rant.
    Adam R, Sep 12, 2003
  7. August

    Frankhartx Guest

    Is there such a format for images that is equivalent to a .PDF? We
    The only way is to encrypt the files-the format is not the problem nor the
    answer. Encryption provides security and there are levels of encryption
    available that would stymie even the NSA
    Frankhartx, Sep 12, 2003
  8. It seems you'd have to have some sort of documentation
    that certified that the image had gone directly from the
    camera to an encrypted format to a CD. The biggest
    cost will be the documentation, I imagine -- some sort
    of notary-public-equivalent-witness with technical expertise to
    witness the process and sign off on it. Or a pair of same.
    The witness would need technical expertise so that
    some geek wouldn't be playing flim-flam games with
    the imagery.

    Myself, if I were a judge, haha that ain't ever gonna
    happen in this lifetime, but if I were, I wouldn't trust
    pictures of anything anymore.
    Stanley Krute, Sep 12, 2003
  9. August

    PlaneGuy Guest

    I believe that Canon has an optional accessory on one (or maybe more) of
    their DSLRs that uses cryptographic techniques to digitally sign the images
    created with the camera. I think it is either the 1D or 1Ds.
    PlaneGuy, Sep 12, 2003
  10. August

    Graham Guest

    Surely burning a dozen images to a 50c CD-R is more cost effective than
    buying, developing and printing a roll of 35mm film?

    And surely a mostly empty CD-R is no more expensive to store than a
    packet of prints and developed negatives?
    Graham, Sep 12, 2003
  11. August

    GrahamH Guest

    But a CD-R is not secure. It is trivial to copy the image from the CD,
    modify it and write back to a new CD. Some (all?) blank CDs are marked with
    a printed serial number that could recorded in the audit trail.

    Usual evidence handling rules must apply of course - sealed containers, full
    audit trail etc.

    Best option is cryptography applied in the camera as mentioned, or as close
    to it (in a processing sense) as possible. For video images use a DVR (or
    other system) with encryption built in.

    A goggle on "digital image evidence law" turns up some interesting links

    GrahamH, Sep 12, 2003
  12. August

    Dave Balcom Guest

    On 11 Sep 2003 17:20:30 -0700, (August) wrote:

    }Is there such a format for images that is equivalent to a .PDF?

    How about keeping the original RAW files? That is supposed to be like
    a film negative. Any modifications to a RAW file are stored in non-RAW
    formats so the original remains unchanged. You could use some type of
    digital signature like someone else suggested on the RAW file for
    double protection.

    Being in law enforcement myself, a photo is supposed to be used as a
    tool in a trial, supporting the testimony of actual people who saw
    what was photographed. Digital is certainly easier to manipulate than
    film, but it was not impossible to doctor a negative either. That is
    where the human element comes in.

    Dave Balcom, Sep 12, 2003
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.