What program is best at JPEG compression?

Discussion in 'Digital Photography' started by u235bomb, Jul 19, 2007.

  1. u235bomb

    u235bomb Guest

    Are some graphics programs better than others for compressing JPEG?
    A friend swears that Image Ready is the best for getting the
    smallest file with same quality.
    But I see a few companies have made utilities purely for
    compressing pictures, and claim they obtain better
    compression than the top tier graphics programs.
    I presume there are different numerical routines used by
    different companies in their software, but I would guess
    maybe 5% variation in file size at best.
    I know there was a comparison done several years ago,
    but the website with the pictures seems to be kaput.
    (www.imagecompress.com ?)
    Is there a recent comparison of different programs to see
    who offers the best compression?
    That is, best quality for same size, or smallest size
    for same quality.
     
    u235bomb, Jul 19, 2007
    #1
    1. Advertisements

  2. u235bomb

    CSM1 Guest

    Jpeg compression is a big subject, since JPEG is a lossy compression scheme,
    there are always trade offs. File size vs. amount of compression and
    artifacts.

    The better Graphic programs give you a choice of the amount of compression
    used.
    The de facto best Photo editor it Adobe Photoshop. The full version is about
    $650 or $150 for the upgrade.

    Photoshop Elements is a consumer grade Photo editor that costs much less
    money ($100) and does most of what Photoshop CS does.
    http://www.adobe.com/products/photoshopelwin/
     
    CSM1, Jul 19, 2007
    #2
    1. Advertisements

  3. u235bomb

    Scott W Guest

    I have a program called Advanced JPEG Compressor, it gives you far more
    control in how the compression is does and allow you to use different
    amounts of compression in different areas of the image. It can do a
    better job, but takes a fair bit of use to use and the gains are fairly
    small. I only use it when posting to the web and where I am really
    trying to limit the file size of the photo.

    Scott
     
    Scott W, Jul 19, 2007
    #3
  4. There is an old plugin available for any of the ACDSee viewers and editors,
    called "RealOptimizer". I don't know if you can find it anymore, I got it years
    ago. You may have to hunt the pirate and warez resources on the net to run
    across it again. I'm not sure what RealOptimizer is doing but I consistently get
    much much smaller image sizes with virtually no detail lost nor artifacts
    introduced, even at 50% compression.

    If retaining the most detail is needed for the smallest possible file sizes then
    I go out of my way to use this. I run ACDSee's old "PicaView" program on XP, I
    believe it came included with their "ImageFox" program, so I can just
    right-click on any image file in Explorer to see its thumbnail, then choose the
    RealOptimizer plugin as a stand-alone application from that PicaView menu in
    Explorer.

    In testing a 6 megapixel 2816x2112 image just now with a lot of detail in it
    (foliage and animal fur), the original 3meg file compresses down 416k at
    RealOptimizer's 50% setting with virtually no image degradation nor downsizing
    needed. I wish I knew how it does what it does so I could apply their
    compression method to other JPG optimizers that allow you to set sub-sampling
    options.
     
    GilfordBrimly, Jul 19, 2007
    #4
  5. u235bomb

    Bill Tuthill Guest

    GIMP is probably the best because it gives you all the control you need
    with a relatively simple user interface.
    I doubt anything from Adobe would be good at JPEG.
    Supporting NIH public standards is not their forte.
    Photoshop is particularly poor at JPEG rewriting,
    because it lacks flexibility.
    Using 4:2:2 chroma subsampling saves a lot of space
    without reducing quality.
    Much of the variation comes from preview, header comments, EXIF, etc.
    There is a good article about JPEG on the photo.net site:
    http://photo.net/learn/jpeg/
    Nowadays the discussion is about old JPEG versus JPEG 2000.
     
    Bill Tuthill, Jul 19, 2007
    #5
  6. u235bomb

    Jonathan Guest

    I use one in particular called Adobe PhotoDeluxe that gives options of jpeg
    compression such as Baseline(standard), Baseline Optimized and Progressive
    and then gives an option to save paths. I guess Jpeg is not a simple file
    format.

    I also like IrfanView and Xnview among others.

    Jon.
     
    Jonathan, Jul 19, 2007
    #6
  7. u235bomb

    Bill Tuthill Guest

    I like Irfanview too -- it is a great image and slideshow viewer --
    but it does not control chroma subsampling.

    Xnview is available for Linux, apparently. Do you prefer it to xv?
     
    Bill Tuthill, Jul 20, 2007
    #7
  8. You can turn subsampling off in Irfanview by ticking an option during
    saving.

    I mainly find that useful when there are important red areas in an image,
    because otherwise they come out very poorly in a JPEG.

    I would agree with the person who said that Photoshop is amongst the worst
    - I find I can always shrink a Photoshop-saved JPEG significantly by
    running it through a lossless optimiser (such as Irfanview's) afterwards.
     
    Gordon Freeman, Jul 20, 2007
    #8
  9. u235bomb

    Jonathan Guest

    What is xv? I think I must have missed something somewhere. Like another
    poster related. I only use Jpeg for uploading to usenet and I am not that
    concerned much beyond that point.

    Jon
     
    Jonathan, Jul 20, 2007
    #9
  10. u235bomb

    Steve B Guest

    I don't know if it's the best, probably not, but the Optimizer in the 'Save
    As' options in Paint Shop Pro 9 is really handy for compressing pictures
    down to a small size. It allows you a real-time view of a zoomed crop
    while the compression factor is changed so that artefacts can be seen. That
    way, the max compression for a particular picture is easy to find and it
    also predicts the file size, handy for web posting.
     
    Steve B, Jul 20, 2007
    #10
  11. u235bomb

    Steve B Guest

    Thee only problem with this is that jpg artefacts are usually first noticed
    as blocking in large areas of slightly varying tone like the sky. Were
    there any areas like that in your test photo?
     
    Steve B, Jul 20, 2007
    #11
  12. u235bomb

    Guest Guest


    Jon,

    Don't worry your pretty little head about it. :)
     
    Guest, Jul 20, 2007
    #12
  13. u235bomb

    Mike S. Guest

    The xat.com Image Optimizer, and JPEG Wizard (Pegasus Systems) are two
    similar products that work somewhat differently, and have differing
    additional feature sets - but also allow direct visual manipulation of the
    trade-off between file size and image quality on a per-area basis within
    the image. As you say, mainly for web posting of where size is of absolute
    importance (like when we email photos to relatives using dial-up
    connections).
     
    Mike S., Jul 20, 2007
    #13
  14. u235bomb

    Bill Tuthill Guest

    Do you mean "Disable color subsampling" option in the JPEG/GIF dialog?
    I had not noticed it before, but upon testing, it only switches between
    2x2 (default) and 1x1 chroma subsampling. It can't set 4:2:2 like GIMP.
    And Photoshop's Save For Web produces remarkably lousy quality, allowing
    (if I'm not mistaken) quality 99-100 with 2x2 chroma subsampling, which is
    just stupid. Anything above about Q 85 should use 1x1 or 4:2:2.
     
    Bill Tuthill, Jul 20, 2007
    #14
  15. u235bomb

    Bill Tuthill Guest

    XV is an old Unix/X11 program by Jon Bradley that's much like Irfanview,
    though obviously not as modern. For example, xv 3.10 lacks EXIF support.
    Irfanview is better in some ways, worse in others. I use xv on Linux
    because Irfanview runs only on Windows, and GIMP (like Photoshop) is more
    an editor than a viewer.
    In theory that is the best plan, but my friends are often sending me
    JPEG files from digital cameras incapable of producing RAW. So I have
    learned how to edit JPEG with minimal damage.
     
    Bill Tuthill, Jul 20, 2007
    #15
  16. Irfanview runs just fine under wine.
     
    Allodoxaphobia, Jul 21, 2007
    #16
  17. u235bomb

    imbsysop Guest

    I've always thought jpeg and its compression algorithm were subject to
    a general standard and not to any program makers' fantasy ..????
     
    imbsysop, Jul 23, 2007
    #17
  18. imbsysop wrote:
    []> I've always thought jpeg and its compression algorithm were subject to
    There is a standard, but with a large number of different choices. For
    example, you can change the colour resolution relative to the luminance
    resolution. How different programmers interpret "95% quality" is up to
    them, so it's entirely possible that different programs will better suit
    different images.

    Cheers,
    David
     
    David J Taylor, Jul 23, 2007
    #18
  19. u235bomb

    David Guest

    As with MPEG, JPEG decoders are deterministic (given the
    same input, they all produce the same output), but the
    encoders are not. Choices can be made during encoding even
    for algorithms that produce the same output file size. MPEG
    encoding has even more variance and there can be enormous
    quality differences in the decoded output of a given average
    bit rate. Coders for DVDs do a good job because the encoding
    does not have to be done in real time and multipass encoding
    and larger GOP sizes are used.

    David
     
    David, Jul 23, 2007
    #19
  20. u235bomb

    Martin Brown Guest

    The standard has a large number of free parameters in it. And although
    many applications use a scaled version of the original canonical
    quantisation table given in the standard other encoders have made
    different choices. And in some cases an encoder with all the time in
    the world can find an optimised quantisation table for a specific
    target image. This helps encode physically small dimensioned images in
    a more compact JPEG file.
    Sadly even though the specification of JPEG is fairly precise there is
    still enough latitude for the decoder that there is plenty of scope
    for different decoders producing different images from the same JPEG
    encoded file. The most commonly noticeable implementation differences
    are in the chroma subsampling treatment (seriously broken in PSPro 9's
    encoder). And where for example the IJG codec uses interpolation
    whereas Adobe uses pixel replication - both of these methods have
    their merits and demerits.

    There are other options dating from the bad old days when computing a
    DCT was still hard work that permit various speed for accuracy trade-
    offs (much less of an issue these days with fast hardware floating
    point support).

    Regards,
    Martin Brown
     
    Martin Brown, Jul 23, 2007
    #20
    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.