[Digikam-users] How do you generate good quality jpegs from raws quickly, automatically ?

[Martin (KDE)]

Am Mittwoch, 23. Dezember 2009 schrieb Linuxguy123:
> This is a follow up to my "How does digiKam do raw conversions for
>  the slide shows ?" post from earlier today.
> 
> So... I shot 600 raws at a wedding last weekend.  In digiKam the
> previews of these files look awesome.  Apparently they come from a
>  jpg embedded in the raw file.
> 
> I need to convert the raws to jpegs.   I also have another 2,000 or
>  so raws to convert.
> 
> The problem with converting raws to jpegs automatically is that
>  they almost never look as good as the preview images.  Please
>  don't tell me to shoot jpgs alone because when I spend a lot of
>  time on an image I can get it looking a lot better than than the
>  preview image, especially if the white balance is out and I
>  happened to shoot a grey card image from which to adjust the white
>  balance.  This happens frequently when I shoot in mixed lighting
>  situations, which happens from time to time.
> 
> If I were a lazy man I would just extract the jpgs from the raw
>  files. But that seems like a waste given that we have all these
>  fancy raw converters and all the glorious raw pixel data sitting
>  in the raw file.
> 
> I've used a number of tools (ufraw, Raw Studio and the digiKam
>  tools) and they usually come out looking pretty horid.  I can't
>  figure out why. The white balance is usually way out, the
>  saturation usually needs adjustment and sometimes even the
>  exposure is off.  I can fix all this stuff, but it takes a lot of
>  TIME.  I'm looking for something that doesn't take a lot of hand
>  tweaking.
> 
> This raw conversion issue is a big problem for me.  Its the main
> bottleneck in my whole photography workflow, now that I have
>  digiKam anyway.  Before everything was a bottleneck.  Now only raw
>  conversion is.  digiKam rocks !
> 
> FWIW, I have raw images from a D50, 40D and 450D.
> 
> So how do you convert your raws to jpgs automatically and get a
>  good result, ie something close to the preview jpg ?  I would
>  prefer to use the tools in digiKam but will consider using outside
>  tools and eventually write a plugin to use them in digiKam.

I usually use UFRaw to set exposure, white balance etc. and safe it as 
ID file only (ID file contains settings only and is much faster to 
save than a jpeg or png). After that is done, I run ufraw-batch with 
the ID files (which can take very long).

I have created a curve which matches (almost) the EOS30D one. I use 
the EOS standard icc profile with gamma set to 0.45 and linearity to 
0.1. Additionally I set saturation to 1.1 and enabled auto black-point 
adjustment.

Most raw files looks pretty good with this settings. If many pictures 
can be developed the same way, you can use one ID file for many raw 
pictures. But I take the extra time to set some values for every 
picture.

My results mostly looks better than the embedded jpegs. Color is a 
little less intensive but I think more accurate.

Martin

> 
> 
> Thanks
>