Discussion in 'Digital Cameras' 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
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  2. 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
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  3. 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
  4. 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
  5. 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
  6. Caien

    Ed Ruf Guest

    Why are you not choosing to save in the native format of your graphics
    Ed Ruf ()
    Ed Ruf, Mar 21, 2007
  7. 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
  8. 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
  9. 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
    HEMI-Powered, Mar 21, 2007
  10. 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
    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
  11. 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
  12. 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
  13. Caien

    Mardon Guest

    I use Photoshop, so I'll speak to that software. If you plan to do all of
    your editing in a single session, then it is unecessary to save your work
    to a lossless format before editing. As others have suggested, it is a
    good idea to always work on a duplicate copy of the original jpeg image and
    save that original in a safe place. Saving to jepg does not cause the
    image that is still being worked on within the editing software to lose
    quality. The quality loss that people are talking about occurs during the
    process of saving the image to jpeg. If you save an image to a lossy
    format like jpeg, and subequently load that image into your editing program
    to do more editing, then you will be working on an image that has had loss
    introduced and this is not a good thing to do. Supposing, however, that
    you want to save a jpeg image to two different sizes. You can save the
    larger image first, then resample to a smaller image and save that one.
    This does not introduce anymore loss than if closed the program after
    saving the first file and reloaded the original image before resampling for
    the smaller file. BTW, it does help a bit if you shoot in Adobe RGB color
    space and don't convert to sRGB until the final file is saved.
    Mardon, Mar 21, 2007
  14. Caien

    alex Guest

    Definitely. I would use your favorite editor's format for this.
    I would avoid this and save edited photos in a standard, lossless,
    compressed format (png is my first choice, tiff a distant second).

    Standard, so you are not tied up to a specific program or OS. Further,
    if 50+ years later your kids want to see those pictures they will not
    have to fish for some obscure software that was written by a company
    long gone and only runs on hardware that has not been made for decades.

    Lossless. When saving in JPEG the errors accumulate. With lossless
    format you can continue making small changes in the future.

    Compressed, so the files are (somewhat) smaller.

    You pay for losslessness with bigger files (maybe 1.5MB per MP, ~15MB
    for a 10-MP image, YMMV), but with current prices for hard drives the
    additional cost for extra storage and backup is minimal.

    For specific format choice: I like png, tiff is OK as well. There is an
    OK (compression-wise) lossless mode in JPEG 2000 but it is not too
    popular. Finally, some basic operations (rotation, cropping) can be
    done losslessly for JPEG and there are free programs to do this.
    alex, Mar 21, 2007
  15. Yet, did not the OP ask about saving in TIFF? So how much different is this
    compared to saving in PSP or PS native file formats?
    Ed Ruf (REPLY to E-MAIL IN SIG!), Mar 21, 2007
  16. Caien

    HEMI-Powered Guest

    Today, Ed Ruf (REPLY to E-MAIL IN SIG!) made these interesting
    comments ...
    They are clearly different depending on whether TIFF compress is
    or is not used and PSD vs pspimage both vary widely depending on
    the content of what is being stored. But, my comment stands, at
    least for myself. When I want full capability, which is VERY
    rare, I use pspimage, else JPEG. Why is that so much heresy to
    you and ther other purists around here? It isn't the format that
    is at all important, it is the content of the image both
    artistically and technically.
    HEMI-Powered, Mar 21, 2007
  17. Why? Since it would seem your editing technique apparently does not make
    use of adjustment and/or mask layers why would you waste 2x as much space
    as using say JP2K in lossless mode to save for even your full capability
    Maybe because some of us have seen the benefits to have graduated to making
    our edits in 16 bit space? But I see you have all ready begun your classic
    escalation posting technique and begun the name calling. What's next the
    foul language ridden posts?

    Believe it of not many folks who visit this forum are actually interested
    in printing their photos and want the prints to be the best they can. It's
    funny though you don't get the 8 vs 16 bit editing issue since all you care
    about is viewing on a monitor, which can more easily show the limitations
    of this. And if you don't get this, you'll never understand why some shoot
    raw for some things.
    Ed Ruf (REPLY to E-MAIL IN SIG!), Mar 21, 2007
  18. Caien

    HEMI-Powered Guest

    Today, Ed Ruf (REPLY to E-MAIL IN SIG!) made these interesting
    comments ...
    You are an elitist and a prima donna who cannot bring themselves
    to even consider alternative views than your own, so enjoy
    yourself as you do things and I will do the same.
    HEMI-Powered, Mar 22, 2007
  19. Caien

    Signal Guest

    I don't know if this is what you're after (this is rather basic and
    you sound like you have expereince) but here's a little guide to using
    Signal, Mar 22, 2007
  20. Caien

    Signal Guest

    The "fine" JPG images coming out of my camera have worse artifacts
    than RAW images which I convert manually. :(
    Signal, Mar 22, 2007
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