howto get thumbnail from EXIF

Discussion in 'Digital Photography' started by cartoper, Mar 26, 2007.

  1. cartoper

    cartoper Guest

    I know that a lot of images have tiny thumbnails images, like 180x120,
    but I also know that some have medium sized thumbnails embeded
    somewhere else in the EXIF. Does anyone know where/how t get to this
    larger thumbnail? I am working in C/C++.

    cartoper, Mar 26, 2007
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  2. cartoper

    Richard H. Guest

    Check out ExifTool. It already has this implemented in Perl.

    What's embedded in EXIF can vary by camera, but as example a Nikon RAW
    file has 2 JPEGs (one full-size, high-compression; one thumbnail) in
    addition to the raw.

    Richard H., Mar 26, 2007
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  3. cartoper

    ForrestPhoto Guest

    I could tell you if you were working in C#, but...

    Did you look through the documentation for the exif format? It's
    pretty horrid stuff to try to follow, but might have what you need.
    ForrestPhoto, Mar 26, 2007
  4. cartoper

    Paul Mitchum Guest

    Paul Mitchum, Mar 26, 2007
  5. cartoper

    cartoper Guest


    I took a quick look at ExifTool, I don't care for the license. But
    libexif looks like it might do the trick.

    It is funny that you mention Nikon RAW, that is the only one I know
    for sure that does it. Do you know how to extract the full rez, high
    compression jpeg from the Nikon RAW file? I get the impression that
    Nikon has placed a special tag in the EXIF that contains the full rez,
    high compression jpeg. Do you know what that tab might be? Is it a
    generic tag that others might also use?

    Oh, I have the Nikon D2H, the second jpeg is not full rez, it is about
    600x400 or something like that. It is what CaptureOne displays, which
    is why CaptureOne only shows small images with my D2H.

    cartoper, Mar 26, 2007
  6. cartoper

    Jim Townsend Guest

    There are fee public libraries that allow you to do all sorts of
    stuff with EXIF info. Just include what you need with your code.
    Jim Townsend, Mar 26, 2007
  7. cartoper

    bugbear Guest

    Your choice of GPL or "artistic"

    What's not to like?

    bugbear, Mar 26, 2007
  8. cartoper

    ray Guest

    dcparse will extract previews from kodak raw images - that is part of
    dcraw or ufraw. I would expect that imagemagik would have that ability.
    ray, Mar 26, 2007
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