Re: [Shotwell] GSoC idea: Shotwell parametric RAW development

[Adam Dingle <adam yorba org>]

On 03/26/2012 02:37 PM, Camilo Polymeris wrote:
> Hello all,
> my name is Camilo, I am a student&  amateur photographer.
> I'd like to propose an idea for GSoC 2012: Implementing parametrized
> RAW development in Shotwell.

Hello Camilo - thanks for getting in touch.

> A bit of background: I use shotwell for classifying&  sorting photos
> everyday, both raw&  jpeg. Additionally i develop the former using
> rawstudio. This is an excelent tool, but I would rather have
> everything unified -- UI, export possibilities, saving behaviour, etc.
>
> Also, my needs regarding RAW development are quite simple: adjust the
> tonal curves (contrast, saturation, temp, etc...) crop, straighten,
> lens correction&  sometimes a bit of denoise. Even if only a subset of
> these could be done directly in shotwell, it would be a great
> improvement.
> I believe I am not the only one who would benefit from this, and its
> interface could be hidden away from the basic user, so to not
> complicate their workflow.

We agree this would be a nice enhancement to Shotwell sooner or later.  
Your proposal more or less corresponds to this Shotwell ticket, which 
we've had open for a couple of years now:

http://redmine.yorba.org/issues/1625

> I am currently writting a more detailed proposal, but would welcome
> any comments on this idea, in particular:
>
> a) Do you think this can&  should be implemented as a plugin?

Shotwell's plugin system is currently limited: a plugin can only 
implement an import source, a publishing destination or a slideshow 
transition.  There's no way that these enhancements could be a plugin 
today, and I don't think it makes sense to try to fit them into a plugin 
anyway - if we implement this it should be part of the Shotwell core.

> b) My work plan includes spending the first GSoC term adding the
> necessary hooks and parameters to the shotwell core&  the second term
> developing the UI&  each tool's particular behaviour. All in all, do
> you think that is a good approach?

I think this would be a pretty challenging summer project.  We've been 
impressed with the patches you've sent us so far in 
http://redmine.yorba.org/issues/4940 and so you may well be up to the 
task, but I think you should spend some time looking at the code to 
convince yourself that you think this is really doable in a summer.

One issue is that RAW support in Shotwell is currently slightly broken.  
In 0.11 we added the ability for the user to switch between the camera's 
development of a RAW photo (in an embedded or paired JPEG) and 
Shotwell's development generated using libraw.  But we were on a tight 
schedule and weren't able to iron out all the bugs either for the 0.11 
release or for the following 0.12 release (where the GTK 3 port took up 
tons of time).  So this area of Shotwell remains buggy - see, for example

http://redmine.yorba.org/issues/4261
http://redmine.yorba.org/issues/4262
http://redmine.yorba.org/issues/4692

I hope we can improve the situation this spring, but these bugs might 
still intersect with your work a bit.

Here are some things to ponder: in Shotwell's enhance dialog, which of 
the adjustments there could be made in libraw?  Which adjustments will 
need to be made later in the pipeline?  Does libraw have all the 
customizable parameters we need today, or will we need to propose 
changes to libraw itself to make all this work nicely?  Can the enhance 
dialog look exactly the same for RAW photos as it does for JPEG photos, 
or will we want to add some bells and whistles for RAW?  Or should there 
be an entirely separate dialog for RAW adjustments?  With your proposed 
changes, will the user still be able to open a RAW photo in an external 
RAW editor?  If they have adjustments both in Shotwell and the external 
RAW editor, which take precedence?  I think we'd want to have pretty 
good answers to all these questions before deciding to embark on this 
project.

> c) If you are a shotwell developer, would you be willing to mentor this project?

Yes - either I or others on the team at Yorba could mentor.  :)

adam