RAW Management and Conversion in Linux

Today, I was playing around with Linux, and RAW management. Not wanting to carry a laptop just for photo editing (i.e. I plan on travel without my MacBook Pro, and beautiful Lightroom, Aperture, iView Media Pro [okay, Microsoft Expression Media now], and Photoshop CS2), I figured I should make Linux up to scratch.

My favourite photo browser, is GQview. Its not standard software any longer, but its pretty old, and it works fairly well. It however, doesn’t support RAW. Today I discovered f-spot (ok, I discovered it ages ago, but I didn’t like its iPhoto-ness, where it wants to import stuff for you). Never fear, that’s what

    f-spot --view <path>

is for. Shortcut wise, its a little different, so I just use the up/down arrow keys to browse.

Now to convert the RAW files to JPGs, with preservation of EXIF data. I played around with the commands manually after reading the man page for dcraw, and figured there must be a better way. So I hopped on over to Yahoo!, did a little search, and came up with Jamie Zawinski’s mvpix. After changing the script a tad bit to suit my environment, I have images! RAW, JPEG, and copies of the JPEGs in an EDIT folder. mvpix also works on OS X.

The options being passed to dcraw seem to be simple: -w for using camera supplied white balance, -t 0 for no tilting, and -c for writing decoded images to stdout. Its passed to cjpeg, and run at 95% quality. However, the images seem to be a tad different, and I have no idea why.

On left, is when the camera was shooting in RAW+JPEG, and on right is the JPEG generated from the RAW file (click for larger image). These are 100% zooms.

The colour differences befuddles me. Why does the camera come out with “brighter” RAW, and dcraw come up with paler tones?

On left, is what the in-camera JPEG gives, when you’re shooting in RAW+JPEG, in the middle is what UFRaw sees from the RAW file, and on the right is what the converted JPEG looks like, after being parsed through dcraw+cjpeg (click for larger image).

What gives? Are there better options in dcraw to give me an as-close-to-in-camera JPEG experience? Are the converted images better/more true coloured? I’m not sure which to pick, and I’m not sure what’s the correct setting, to be honest.

Now about the photos. Apologies to the girl pictured here, all I know is that she’s probably a student at the Caulfield Campus of Monash University (so no, I don’t know her name). She was randomly picked for some quick studio photos, which was really just a bunch of us playing with a few studio strobes, and having the power of wireless triggers. These photos all rolled off an EOS 350D digital back, with a 50mm/1.4 lens attached to it, shot at f/1.6, at 1/25s. Sure, this should have really been made at f8, but there was no time to coax the girl.

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  1. s2 says:

    some questions 1st, Colin if I may?

    1. What colour profile have you got your camera set to?
    2. What monitor profile are you using
    3. Does the software you use permit you to import any profiles or add them from your camera?

  2. I agree with s2. RAW images are usually saved as Adobe RGB color profile, and they’ll look dull in profile blind systems like Linux, Windows, or even Firefox on the Mac. Convert your image into sRGB and see the colours improving :)

  3. Thadeus says:

    A year later and it is still like that. Using F-Spot they come out better, but converted from dcraw they look horrible!