[Digikam-users] Idea for getting in camera quality jpeg conversions... was Re: Building a better raw conversion tool for digiKam ?

[Martin (KDE)]

Am Donnerstag, 24. Dezember 2009 schrieb Milan Knížek:
> Linuxguy123 píše v St 23. 12. 2009 v 19:51 -0700:
> > I did a lot of reading and this might work.  But generating color
> > profiles using an IT8.7 target and using a raw converter that
> > supports the use of color profiles is the ultimate answer.
> 
> Do not get mistaken - using the colorimetric approach only will
>  result in good (hopefully) colours, which is not what the camera
>  does (convert colours with preference of skin-tones, green, etc.,
>  adjust tone curve, saturation). A photographer usually wants to
>  get pleasing (good looking) images, not high-fidelity images.

I think it is a little bit more than that. With such a ICC file you 
get a exact (within the limits of the sensor) copy of the scene, 
including gamma, curve and saturation correction to get it. From a 
technical point of view this is the best you can get.

What you don't get are the emotions in the picture. For this you have 
to adjust several parameters, and sometimes you will add stuff you 
normally avoid to get (like false colours and noise).

But as a base this work-flow may be the best start. I am still trying 
several ways to get the best out of my pictures. And it does not make 
much sense to fix some green (or red or blue) colour in your picture 
if you don't use a colour managed environment. This includes the 
printing stuff as well. Sadly most print labs don't offer colour 
management (at least here in Germany).

> 
> The ICC profile will do only the first step and unless you use an
>  ICC profile editor to store the manual adjustments in the profile,
>  the other corrections are to be done in image editor manually...
> 
> With UFRaw, you have better chances for automation, since you can
>  adjust linear curve (before gamma is applied), lightness curve (in
>  L*a*b* space after gamma/ICC profile is applied), saturation and
>  keep these settings for later use.
> 
> However, you still do not have the possibility of unique colour
> adjustments (e.g. make skin tones warmer and do not affect too much
>  the other colours).

It would be great if ufraw gets this settings. As RawTherapee will 
become GPLed software, the developer may take a look at it. This 
software has some really fine features.

> 
> Regards,
> 
> Milan Knizek
> knizek (dot) confy (at) volny (dot) cz
> http://www.milan-knizek.net - About linux and photography (Czech
> language only)

Martin