Mailinglist Archive: opensuse (1367 mails)

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Re: [opensuse] Writing coments on photos problem - yes, again! O:-)
On 01/31/2016 04:21 PM, Carlos E. R. wrote:
On 2016-01-31 15:14, Anton Aylward wrote:
On 01/31/2016 09:05 AM, Carlos E. R. wrote:
It appears to read the tags and comments created with shotwell, but I do
not see how to create comments. But only if the photo is jpeg: not on
the .nef/.jpg pairs made by my Nikon reflex camera.

Please see my comment on why comment/author/copyright information should
be embedded as early as possible in those RAW file using exif and not
rely on external sidecar files or external databases.

Both programs write exif tags and comments. The problem appears when
each photo has 3 files:


Ie, the camera generates both XXXX.nef and XXXX.jpg.

Well its not really 3, but I see your problem.
You don't have a single unambiguous "original'.

*YOU* have chose to set your Nikon to generate "RAW+JPG".

The point is that the JPG it generates can be any one of the 'scene" and
manipulation options your Nikon has.,-nef,-compressed-nef,-tiff,-and-jpg-file

You may not have chosen the one best suited to the image you want to
present. Even if it is the one that the name of matches the scene.
That JPG is what the camera's internal algorithms generate from the TAW
data at the sensor.

I read reviews of cameras I think about upgrading to at DPReview, for
example, and see in their detailed reviews many critical analysis of the
RAW-to-JPG conversion in the camera.

This motivates me not to use the "RAW+JPG" and simply to do the
conversion to JPG using Darktable from the single unambitious original
RAW file. Its about quality.

I should point out that darktable also lets me do manipulations that are
way beyond what the camera can do, making, shading, spot elimination,
applying various correction filters, a wider range of "scene" settings,
playing with grey-scale, overlay, and of course it can also produce TIFF
and other 16-bit formats that are less lossy than JPG or GIF.

So my list of files ends up as

original camera generated RAW to which I apply the copyright
darktable generated sidebar file
any number of JPG files generated by darktable
any number of tiff files generated by darktable
any number of JPG-2000 files generated by darktable

and so on.

When shotwell
imports them, it generates another jpg file.

Are you saying that it automatically generates them on import?
I don't like that. But such is your choice.

I think the comments are
saved to the jpg file, but I'm not sure. It can not write to the .nef file.

A photoeditor should NEVER alter the original.
My point about adding copyright to the RAW is that I'm paranoid about
getting in there before any derivatives can be made. If my camera
allowed me to insert the author/copyright information "at source" then I
would use that. It doesn't, so I edit the RAW files with exiftools.


Digikam does not see the comments or tags of these photos. I don't know
yet why. It does see them if made on cameras that generate a single jpg

There are many cameras, not least of the camera capabilities of
cellphones, that ONLY generate GIFs or JPGs. I'm not saying that a
cellphone can't produce a great photographs; put one in the hands of a
professional and he or she will produce consistent quality just as
easily as of were a high end DSLR or a 1950s Kodak box camera.
Ultimately skill and creativity will trump technology. But that's not
what we're talking about here.

Neither does digikam notice that those 3 files are a single photo.

Of course not, its not a semantic scene analyser, some form of AI.
its only a photo editor. if I adopted it after generating 50 to 60
variations on one RAW file, apply various 'scene' pre-sets, using
darktable, it wouldn't recognise those either. The only reason
darktable "does" is that it has its own database and history. So we're
back to something 'external'.

It is *YOU* who have chose to set the camera to produce "RAW+JPG" and it
is *YOU* who selected the scene setting from which the camera's internal
algorithms produced that JPG from the RAW. If you don't like that then
why are you also producing the RAW, uploading it and using an image
editor on it? Why not use just RAW and then "Hmm, that's a flower, OK
apply pre-set flower and see what I get. Hmm, don't like that, go back
to the raw and mask out the foreground and apply "bokeh" filter to the
background. Better. Now lets play with the colour curve of those
petals." BTDT.

A street near me has, fashionable, what looks like old gaslights even
though they are actually electric. A RAW of that taken in brilliant
sunlight on a cloudless day, make B&W in darktable, ad back spots of
colour, highlight grain using solarization to give the effect of rain
and most, , a wonderful "noir" Victorian street at dusk.

Sorry, there's no camera "scene" setting to do that. This is art. The
camera is a tool. While I'm happy to let it do the focusing and for me
and get the exposure close to what I want, that's mechanics. "Render
unto the computer" and all that as Norbert Weiner said.

If I were dong this 40 years ago in the darkroom I had set up in the
basement, with the enlarger, baths of chemicals, different types of
paper, filters, pieces of cotton, mesh and wire and more, the database
would be my notebook. Like they say, YMMV.

So be asking yourself: Why are you using a photeditor at all if you are
taking the camera's idea of what the editing of the RAW to JPG should be?

And if shotwell automatically generates a JPG on loading, then what
algorithm is being used there? And is that a setting you can turn off?

I can tolerate 'automation' making low level decisions for me, when to
turn the furnace on for the heating as the temperature falls, things
like that. But making strategic, creative decisions, that's another
matter. I very much doubt that shotwell could do recognise "ah a single
close-up of a plant..." and apply the example reasoning, evaluation,
masking and choice of enhancement that I gave in the above example.
So why have it automatically generate a JPG you don't want?

A: Yes.
> Q: Are you sure?
>> A: Because it reverses the logical flow of conversation.
>>> Q: Why is top posting frowned upon?

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