JPG->TIFF->JPG

Discussion in 'Digital Photography' started by Caien, Mar 21, 2007.

  1. Caien

    Caien Guest

    On a recent trip, I took all my photos in high quality JPG's. Does it
    make any sense to convert them to TIFF files for the purposes of
    munipulation, and then convert the finished photo back to a JPG.
     
    Caien, Mar 21, 2007
    #1
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  2. Caien

    Nervous Nick Guest

    I was wondering the very same thing yesterday. I decided that yes,
    that is the way to go, since jpegs recompress each time you re-save
    them and therefore you are losing more data each time you do so.
    Normally I don't worry too much about such issues because the final
    product is only going to be viewed on a monitor, but even if server
    space is the only concern this still seems a sensible practice.
     
    Nervous Nick, Mar 21, 2007
    #2
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  3. Caien

    Martin Brown Guest

    It only makes sense for preventing degradation of work in progress.
    And usually you are better off using the native lossless format of
    whichever package you are using as that can retain other information
    about layers and masks.

    JPG isn't a good choice for saving intermediate results, but unless
    you have shares in a disk driver company you are not gaining anything
    by expanding JPEGs to TIFF files just for the sake of it.

    Regards,
    Martin Brown
     
    Martin Brown, Mar 21, 2007
    #3
  4. Caien

    Bob Willard Guest

    To avoid the loss due to successive recompressions, I try to not
    save intermediate copies. I keep the original .JPG, and then make
    all changes (color correction, rotation, cropping, etc.) before
    committing to one final save. If a correction doesn't work out,
    I either back out of that correction by ^Z, or restart by closing
    without saving and then re-opening the original .JPG.

    And I use save settings for the largest file possible, which means
    minimal compression and minimal loss.
     
    Bob Willard, Mar 21, 2007
    #4
  5. Caien

    HEMI-Powered Guest

    Today, Caien made these interesting comments ...
    Yes and no. First, ALWAYS put the files no matter what format from
    your camera's memory card(s) and put them some place safe, at least
    in a sub-folder under where you intend to save the final versions.
    ALWAYS back the folder(s) up! Now, when you do start on your post
    processing, to whatever workflow you think works best for you,
    ALWAYS work on a COPY of the original. The format(s) you decide on
    really are determined by the feature(s) you want to save. e.g., if
    you want to save layers and vector data, then you must save in a
    lossless format, likely one proprietary to your fav graphics app.
    If you want to share on the web or Usenet, JPEG may be the best,
    although many people also use PNG and TIFF. If you want to save
    EXIF, you CANNOT compress TIFF, they won't carry EXIF.

    As long as you do not perform multiple edit-save-reedit-save-
    reedit-save cycles on JPEGs you won't get any degradation. A MINOR
    re-edit may be OK if you were circumspect on how much compression
    you used in the first place. But, I try to start anew with the
    original if I find I've made a blunder.
     
    HEMI-Powered, Mar 21, 2007
    #5
  6. Caien

    HEMI-Powered Guest

    Today, Martin Brown made these interesting comments ...
    JPEG is fine for intermediate saves IF you change the file name for
    each iteration. It is not uncommon for me to save 2, 4, 6, or more
    versions and delete the obvious baddies when done.
     
    HEMI-Powered, Mar 21, 2007
    #6
  7. Caien

    HEMI-Powered Guest

    Today, Bob Willard made these interesting comments ...
    Intermediate saves to some format, whether it is a simple BMP,
    TIFF, PSD, PNG, something is really quite necessary to avoid either
    an editing blunder or - God Forbid! - Windows or your graphics app
    dies. If you're really concerned, set an auto-backup from your fav
    app to say, 10 minutes.
     
    HEMI-Powered, Mar 21, 2007
    #7
  8. Caien

    Lionel Guest

    That's totally unneccessary, & makes it very easy to lose your
    correction work. (Not a big deal if you've only spent a few minutes on
    it, of course.)
    Just save as an uncompressed format (eg: .ps, TIFF, PNG) & convert to
    your compressed format when you're finished with it.
     
    Lionel, Mar 21, 2007
    #8
  9. Caien

    Ed Ruf Guest

    Why are you not choosing to save in the native format of your graphics
    program?
    -
    Ed Ruf ()
    http://edwardgruf.com/Digital_Photography/General/index.html
     
    Ed Ruf, Mar 21, 2007
    #9
  10. Caien

    tomm42 Guest


    This is not correct, any save with a jpeg degrades the image. If you
    have a refference that supports the change the file name theory please
    let me know, it would mean a major rethink on handling jpegs on my
    part.
    If you can edit a jpeg with one session then you are probably OK. But
    to be safe use either TIF of PSD (if using layers in Photoshop) while
    editing. I can never get the image I want in one edit. As everyone
    has said save your original jpeg and back it up. Hardrives are big and
    cheap, unless you are saving thousands of images there is no reason
    to worry about TIF files. As you said you can go back to jpeg at the
    end anyway. Still like RAW better especially because of the 16 bit
    (really 12bit) file handling.

    Tom
     
    tomm42, Mar 21, 2007
    #10
  11. Caien

    bugbear Guest

    I think HP is merely doing multiple save-as within a single
    editing session (I hope).

    Therefore all the edits are cumulative
    on the original open'd JPEG, and the save-as
    degradation is NOT cumulative.

    BugBear (guessing)
     
    bugbear, Mar 21, 2007
    #11
  12. Caien

    HEMI-Powered Guest

    Today, tomm42 made these interesting comments ...
    Try to read my post carefully, please. Yes, of course, all JPEG
    saves degrade the image, but unless you are a pro and intend to
    sell prints in some outlandish size like 16 x 20 or 24 x 36, it
    is a rare person who can detect damage when the image is properly
    processed. Of course, it matters not what format is used if the
    camera and the person standing behind it are not skilled.

    And, I believe I qualified my comments in the light of more than
    a dozen years of experience in this game, all of it as a
    hobbyist. In my experience, FAR more damage is done by using
    inferior equipment and from not being nearly skilled enough to
    properly post-process their images.

    I suppose now we'll start the perennial "the more mega pixels the
    better the picture", just so much hogwash unless properly
    qualified a dozen ways from Sunday.
     
    HEMI-Powered, Mar 21, 2007
    #12
  13. Caien

    HEMI-Powered Guest

    Today, Ed Ruf <"Ed Ruf (REPLY to E-MAIL IN SIG!)" made these
    interesting comments ...
    Maybe because it may be 10X or more larger in KB for no apparent
    reason? Not everyone is a pro or views themselves as one, or has
    any idea how to take a digital photo and properly post-process it,
    no matter what the final format used. And, unless I missed it, the
    OP gave no clue at all as to what they'd taken pictures of, camera,
    lenses, lighting, etc.
     
    HEMI-Powered, Mar 21, 2007
    #13
  14. Caien

    Ken Lucke Guest

    I think that what he's saying is that he saves copies as he's working
    on it [without closing the original file at any point], rather than
    saving them and reopening them to continue to work, therefore he's
    still working on the *original* image, just saving it in multiple
    versions. There's no more loss doing it that way, because even the
    final version is still a "first generation save" from the original.

    HOWEVER, if he were to have to go back to one of those copies to
    retrace [or vary] his steps at any point, then he starts introducing
    the compound loss errors, because the *copy* he saved, whether it be
    version 2, 4, or 364, DID get compressed when saved, so opening it
    starts from that [lossy] compressed version, introdusing even further
    loss. Not to mention that any layers, paths, masks, or channels that
    might have been created and used in Photoshop (or other such programs)
    are lost when saving to the .jpg format. To me, the savings in disk
    space is not worth that.
    Exactly. He apparently can do that - I rarely can. ;^) I tweak, go
    back the next day and look again, play around some more, lather, rinse,
    repeat.
    You can also save layers in .tifs from PS, but it really boosts the
    filesize over the equivalent saves using .psd files.
    Yes, although the *only* reason I can see to use .jpgs is for the web.
    All my printing (and even my web .jpg creation) is done from Aperture
    (directly from the raw+adjustments) or Photoshop (from .psds made from
    those raw+adjustments and exported from Aperture, so I can apply size
    and media specific sharpening). I wouldn't want to lose even the
    tiniest detail because of compression loss for my prints.
    Agreed.

    --
    You need only reflect that one of the best ways to get yourself a
    reputation as a dangerous citizen these days is to go about repeating
    the very phrases which our founding fathers used in the struggle for
    independence.
    -- Charles A. Beard
     
    Ken Lucke, Mar 21, 2007
    #14
  15. Caien

    HEMI-Powered Guest

    Today, bugbear made these interesting comments ...
    Yes, of course. I did some really large multi-part stitched scans
    yesterday from a car brochure, so I was not only saving in PSP's
    native format to preserve layers, selections, and the like, I was
    also saving to alternates of the same basic file name as I
    continued. This isn't a digicam example, but it serves to make my
    point, which is I ALWAYS save to multiple file names to avoid
    anything at all blowing away a hour or 2 or more worth of work.
    But, since I rarely have the need for any of the exotic stuff and
    I only very, very rarely ever have to do a re-edit, I see no
    visible image degradation.

    Now, on the digital side, I normally shoot at 4 MP on my Rebel XT
    unless I am shooting something simple, like owner's cards or
    signage, then I'll drop to 2 MP. Or, if I want to extend the
    range of my zoom lens(es), I may up the size to 8 MP and crop a
    piece out of the middle. But, unless I know I will be printing
    large, e.g., to 8.5 x 11 or larger, I rarely save my final JPEGs
    larger than about 1600 x 1200. For them who care, even on a
    borderless 8.5 x 11 glossy paper print on my Canon Pixma 6600,
    that is still around 145 PPI, which more than satisfies my needs.
    I take nothing away from them who want more, but I cannot see
    You guessed right. Technically, everyone is right: if one starts
    with a JPEG in their camera even at the least compression, there
    will be some degradation. But, given so many parameters that have
    a much larger effect on ultimate image quality, including
    resizing down, straightening, yada, yada, I can't see any damage.
    I will say this: I ALWAYS immediately open the just-saved JPEG
    and look for damage before blowing away the in-memory bitmap,
    which is essentially formatless. In about 1% of cases, I do see
    some damage even at compressions as low as 5-7 on the standard
    unitless 1-100 JPEG scale. So, I will either drop the number
    lower and/or experiment with changing the Chroma subsampling.

    In the end, it is the OP, and only the OP, who can really say how
    much damage there is or is not, and how he/she feels about it.
    The rest of us are, hopefully, just mentioning our opinions and
    experiences.
     
    HEMI-Powered, Mar 21, 2007
    #15
  16. Caien

    HEMI-Powered Guest

    Today, Ken Lucke made these interesting comments ...
    Since JPEG neither saves layers nor the steps I used, unless I
    save them as what PSP 9 called a Quick Script, if I discover I
    went down the wrong road, I must backup and start again. But,
    there are times when I'm unsure the best way(s) to edit a
    complicated problem, so I may save different versions with some
    descriptor in the file name or EXIF to tell me what I did.
    Optical is around 2 bits for 4.7 gig and HD is about 25
    cents/gig, so backup, backup, backup is the watchword I use - to
    multiple places, one of which is my bank's safety deposit box to
    avoid losing everything should there be a fire or wind storm.
    The format(s) one chooses depends on what they intend to do with
    the images, the particulars of how they edited, and many other
    fators. For me, JPEG performs both my needs and my wants
    admirably.
    I would agree also, if somebody believeable could teach this old
    dog how to use RAW! Cannot find any books about it that don't
    assume I'm using either PS CS or Elements.
     
    HEMI-Powered, Mar 21, 2007
    #16
  17. Caien

    Marvin Guest

    Even better, use a format that keeps the information so that
    you can use the revert function to step back trough the
    changes. In Paint Shop Pro, it is the psp format.
     
    Marvin, Mar 21, 2007
    #17
  18. Caien

    Ken Lucke Guest

    Yeah, this is ONE thing I wish Photoshop would do - keep the history of
    changes saved with the file, or perhaps in an .xmp sidecar file. Not
    enough to make me want to switch programs, but just something I wish
    that it did.

    --
    You need only reflect that one of the best ways to get yourself a
    reputation as a dangerous citizen these days is to go about repeating
    the very phrases which our founding fathers used in the struggle for
    independence.
    -- Charles A. Beard
     
    Ken Lucke, Mar 21, 2007
    #18
  19. Caien

    Mardon Guest

    Why not just use the Photoshop "Edit History Log"? You can choose to
    export the text to an external log file, or you can store the information
    in the metadata of edited files.
     
    Mardon, Mar 21, 2007
    #19
  20. Caien

    HEMI-Powered Guest

    Today, Marvin made these interesting comments ...
    What version of PSP are you using? I wasn't aware that what is
    shown in the History Pallette is saved along with a pspimage file,
    except if one creates a Quick Script to augment it. I am using PSP
    9 and believe pspimage files do not save the history. I've never
    upgraded to X or XI because I don't like what Corel did to my
    former fav program for over a decade.
     
    HEMI-Powered, Mar 21, 2007
    #20
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