[KPhotoAlbum] looking for RAW work flow suggestions..

[Michael J Gruber]

Jan Kundrát venit, vidit, dixit 13.11.2008 17:34:
> Michael J Gruber wrote:
>> A while ago I posted a mediafiletype patch which implemented
>> subcategories for images and videos by file extension, so you would have
>> jpg, cr2, nef, png, .. subcategories under images and similar under
>> videos. There you have all your usual searching and set operations. For
>> me it was the only half-way reasonable way for working with jpg+raw in
>> KPA, but the patch didn't make it into trunk. It was against a 3.0ish
>> version of KPA. Is that something which would meet your needs?
> 
> I haven't seen this patch, AFAIK, perhaps you made it before I even got
> involved in KPA. Got a link to it?

I can't beat Martin's response on that one ;)

>> I can't promise porting it to KPA 4. I'm kind of fed up with raw
>> thumbnails and display orientation being broken again in KPA 3.1
> 
> Again? Since you submitted (this) patch, we've switched from an older
> built-in snaapshot of dcraw to libkdcraw. I also recall fixing a bug

I know, usage of libkdcraw lead to a completely different codepath in
KPA 3.1, which is why I didn't look into refixing it (with KPA 4 on the
horizon).

> with image orientation and RAW files. How do I reproduce the problem
> you're speaking about in either 3.1.1 or current trunk?

The problem is that it depends on many factors, see below. Since KPA
uses the standard .thumbails, one convincing test is:

- nuke .thumbnails
- browse your raw files in KDE; this generates (hopefully correct) thumbails
- browse your raw files in KPA

For me, raw thumbnails come out right in KDE and wrong (using the same
thumbail files) in KPA. "wrong" means that portrait oriented images come
out landscape.

In fact, the issue is the old one: for portrait orientation, KPA seems
to rotate once when creating the thumbnail (as KDE does) and once again
when displaying it.
If I recreate all thumbs in KPA, they get displayed correctly until KPA
is finished, then suddenly all protraits get rotated again (wrong).
Tested with KPA svn from last week or so.

Factors this depends on:
For thumbails as well as preview as well as full view, KPA may extract
an embedded thumbnail or an actual conversion of the raw file. It
depends on the requested resolution vs. the resolution of the thumbnail.
The latter depends not only on the make of the camera, but also on the
mode! My Canon 350D (Rebel XT) stores full resolution "thumbnails"
inside the cr2 in RAW+JPG mode (which is idiotic because then thumbnail
== external jpg) but limited resolution (roughly 1500x1000) thumbails in
RAWonly mode. Thus, thumbnails, preview and full view may come out with
different rotations.

My first attempt at a fix for current svn suffered from exactly that
problem, it would work for one type of cr2 but not for the other. I may
have tweaked in the wrong place of the code, though. The fact that KDE
(and ufraw) handle my files correctly indicates that it's not my Camera
doing something fishy (such as rotating the thumbnail and not clearing
rotation info).

Ironically, if KPA fails to detect any orientation but (libk)dcraw does
 (I don't know if that is still possible with the current codepath; it
used to be) then things should just work.

Maybe I'll get myself to test more systematically one day... Or maybe
someone can enlighten me and tell me where exactly in the code rotation
is handled
- for creation of thumbnail/preview/full view instances
- for displaying them

Michael