Black and white dynamic range problem - selective color change?

Discussion in 'Digital Cameras' started by Peabody, Nov 5, 2009.

  1. Peabody

    Peabody Guest

    Well, I don't mean B&W in that sense. I mean I'm trying to take a
    picture of a black grand piano located in a fairly small room with
    white walls, and when the piano looks good, the walls are blazing,
    and you feel an urge to reach for sunglasses.

    I'll try to solve this with lighting if I can, but I wondered if
    there is FREE software that would let me approximately select areas
    of the picture with the mouse, which the software would finish
    selecting precisely based on color, and then let me change the
    color, or at least the brightness, of the selected areas.

    I'm using XnView for general corrective stuff, but it doesn't do
    anything like that unless there's a plugin somewhere. So for XP, is
    this where Gimp comes in? Is there anything with less of a learning
    Peabody, Nov 5, 2009
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  2. Free trial of Photoshop, 30 days,
    John McWilliams, Nov 5, 2009
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  3. Peabody

    Toxic Guest
    Toxic, Nov 5, 2009
  4. Peabody

    tony cooper Guest

    It's cheating to some extent, but you could download the free 14 day
    trial of the Topaz "Remask" program. It's probably the simplest way
    to do a knock-out with Photoshop. I don't know if it's compatible
    with Gimp but it seems like it would be.

    The problem that I see is that you would have to familiarize yourself
    with program you've never used - Gimp or Photoshop - for one
    photograph. Neither are easy programs to learn.

    You wouldn't select by color, by the way. You'd make a selection of
    the piano, knock out the background (walls) on a layer containing the
    selection, have one layer with the piano and a second layer with
    everything beneath that, and adjust each layer with Curves or Levels.
    Pretty simple for an experienced Photoshop user.

    If it's one photograph, you should consider paying someone who is good
    with Photoshop to do the post-processing and give you back a .jpg.
    tony cooper, Nov 6, 2009
  5. If your camera can produce a RAW image, then this is an easy job for a
    RAW converter, and the RAW converter that came with the camera will
    probably be the easiest to use for the job. You want to compress the
    dynamic range between most of the darkness of the piano and most of
    the lightness of the walls. This could be done globally by changing
    the luminance translation curve, or locally by using some kind of
    local dynamic range optimiser, if the RAW converter offers that.

    There are some third party dynamic range converters that will
    automatically try to do that for you on that kind of image, and will
    often do quite a good job. For example Picasa's RAW converter (free
    from Google) does that, and if that doesn't do enough, allows you to
    tweak it a bit more with the shadow fill slider.
    Chris Malcolm, Nov 6, 2009
  6. Peabody

    Peabody Guest

    David J Taylor says...
    Thanks very much. In fact has an example of what
    I want to do using what they call the Magic Wand. So I may
    give that a try. But first I have to install .NET 3.5 :-(
    Peabody, Nov 6, 2009
  7. Peabody

    Peabody Guest

    David J Taylor says...
    No, sorry, I should have said. It's a Canon A590. CHDK
    will make it do raw, but I've never tried that, and I don't
    know if any of the raw processors could deal with those
    files. Anyway, it's only 10-bit as I understand.
    Peabody, Nov 6, 2009
  8. Peabody

    Peabody Guest

    Chris Malcolm says...
    Well, it's a Canon A590, and CHDK can get raw files from it,
    but there's no Canon processor for them, and I don't know if
    things like Picassa would recognize those files either. In
    fact, it's not clear how you're supposed to process those
    files. Anyway, for now I'm just using 8mp super-fine jpegs.

    I've been using XnView, which has a number of global options
    for changes, including contrast. And others have suggested
    HDR software for this. But the problem is that the piano
    itself looks good, including the black case, the white keys,
    and the highlights coming off the polished brass pedals,
    etc. So I really don't want to compress that. I'm pretty
    new at this, but I still think I just want to knock back the
    walls, and leave the rest alone.
    Peabody, Nov 6, 2009
  9. Peabody

    Peabody Guest

    Peabody, Nov 6, 2009
  10. Peabody

    More Info Guest

    Photoline has always opened any of the CHDK cameras' RAW files just fine.
    With various interpolation algorithm options as well. If you don't use that
    advanced editor then use CHDK's in-camera DNG conversion to save your RAW
    file data (DNG4PS intermediate computer step no longer required). Then you
    can open the files direct from the camera in more rudimentary adobe
    products or other editors. 10-bit or 12-bit, depending on camera model.
    More Info, Nov 6, 2009
  11. Peabody

    Peabody Guest

    Floyd L. Davidson says...
    Yes, this whole project has turned out to be about lighting
    much more than anything else. But the close-up shots (the
    under-carriage, the bridges, the dampers, the tuning pins)
    so far haven't been nearly as difficult as the shots of the
    whole thing. I think that's primarily because the walls are
    so close in, and so white. And of course it's easier to
    maneuver the lights on the closeup stuff without having to
    break out the stepladder.

    I will try your suggestions. Thanks very much.
    Peabody, Nov 6, 2009
  12. Peabody

    Peabody Guest

    More Info says...
    Doesn't there need to be a specific profile of some kind for
    each camera model? Or are you saying a DNG file will open
    up in such an application no matter what camera it came

    I have a vague memory of reading somwhere that camera X
    wasn't supported yet by Adobe Camera Raw, so that camera's
    raw files couldn't be opened. (It might have been the LX3.)
    So I assumed the processing software had to specifically
    support the A590's raw format or I couldn't use it.
    Peabody, Nov 6, 2009
  13. Peabody

    Peabody Guest

    Savageduck says...
    Thanks, Mr. Duck, but I don't know what a white balance
    profile is, or how I would create it, or where I would use
    it. And if the answer in any way involves Photoshop, then
    it's just not within my frame of reference right now.
    Thanks for doing that. But I think I need to either replace
    the background completely in the picture, or do something
    completely different with the lighting so I don't have to do
    Peabody, Nov 6, 2009
  14. Peabody

    More Info Guest

    DNG is a standardized RAW format that most editors can open and use.
    Photoline's authors use some RAW file format basics, even being able to
    open RAW formats that aren't on the market yet. (Surprisingly discovered
    when I tested several new RAW formats before there was even an update to
    Photoline to support those makes and models of cameras.) There is the more
    common Import Digital Camera RAW option in Photoline for standard digital
    photography, as well as the Import RAW Image Data option. The latter being
    used to open any unconventional RAW file formats that are found only in
    obscure digital imaging and science circles. Allowing you to select your
    color-space options, bit-patterns (8/16-bit, big/little Endian, etc.), line
    overflow lengths, and header-sizes on the RAW Image Data import dialogue.

    If using their Import Digital Camera RAW reading feature, just be sure to
    set the gamma for Camera RAW files in the setup options to reflect the
    gamma of your workspace (for PCs this is typically 2.20.) If your RAW
    filename's extension (user selectable in CHDK cameras) is then associated
    with Photoline, it will open them up just fine from Explorer by
    double-clicking on the RAW file, using the last settings you used in the
    Import Digital Camera RAW panel. The Photoline authors are also quick to
    update their software to open any new RAW formats that are unique. Rather
    than waiting half a year or more, you usually get the latest RAW formats
    supported in the next release of Photoline, which can sometimes be several
    times a month. E.g. there have been 2 official updates in the last month.
    10 official updates this year so far. Many intermediate updates posted more
    often depending on importance, often not logged as official version
    updates. Check installer filesize, if different it's an update.
    Adobe's software does. They'd rather invent their own proprietary
    conventions and make everyone dependent on them to wait for an update,
    sometimes making their users and supporters pay to do so. Others editing
    software authors do not. Though adobe will support all DNG files (available
    as a RAW default from all CHDK compatible cameras), DNG is one of the few
    things that adobe did somewhat correctly.

    See above.
    More Info, Nov 6, 2009
  15. Peabody

    Bob Larter Guest

    The whole point of DNG is that it's a generic RAW format, so yes, any
    DNG should open on any program that supports DNG.
    Bob Larter, Nov 7, 2009
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