[Digikam-users] Building a better raw conversion tool for digiKam ?

[Mark Greenwood]

On Wednesday 23 Dec 2009 20:34:18 Linuxguy123 wrote:
> This thread is a continuation of the "How do you generate good quality
> jpegs from raws, quickly, automatically ?" thread I started earlier
> today.
> 
> I was surprised to hear just about everyone reply that it was not
> possible to get jpegs from raws that rivaled the jpg embedded in the raw
> without a lot of manual tweaking.
> 
> I am interested in improving the raw conversion tool in digiKam.
> 
> Who has ideas ?
> 
> For starters, which raw conversion tools (regardless of brand, OS or
> not, platform) do a good job of generating jpgs from raws ?

Well, hang on, I don't think it's that simple. I'm about to sound like I'm contradicting my earlier statements here, but I'm not.

Digikam can do a good job, a very good job. As far as I know, both ufraw and digikam use dcraw to actually do the raw decoding.

dcraw is the only raw decoding tool that applies NO corrections of any sort to its output. All other tools on all OSes apply some kind of preset gamma and/or curve - so their initial output will look "better" but to my mind it is defeating the object of using RAW in the first place. I *like* the fact that I get, er, RAW in the raw, as it were :) ufraw does stuff to the output from dcraw that I don't understand, so that is why it looks "better" than Digikam.

Now, it takes longer to get good results because of this, but I've been doing a lot of comparisons of tools recently and I have to say that Digikam gives me the best results, but with the most effort. I've hesitated to say this before now because I was struggling to understand colour management but thanks to this discussion today I've realised I don't need it, so that's good :)

As an example, let me describe how it works with my Nikon. If I use Nikon CaptureNX I can pump RAW files through it with a preset of, say, "Vivid" and it will pump out JPEGs that look great. But I can get *Identical* results by shooting in JPEG with the camera settings set to "Vivid". So why bother with RAW at all? To my mind the whole point of RAW is that I want to adjust each picture individually. If you want to apply the same settings to every picture, shoot JPEG and let the camera do it.

In Digikam, I open the RAW file in the editor and tweak White Balance, saturation, noise, and sharpness until I'm happy. I use different settings for each picture.

What you, I think, want is a plugin or filter that can save a set of default RAW conversion parameters and pass a queue of files through it. This is a completely different proposition than changing the raw import tool. You would either need sensible presets for every make of camera out there, or permit the user to save a selection of various tool settings as a preset. I think that would be useful, especially in your case, and would leave the current RAW editing workflow unchanged.

Mark

> 
> Thanks 
> 
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