[Digikam-users] trouble with image degradation using DK with kipi-plugin: flickr export

[Jean-François Rabasse]

On Sun, 4 Mar 2012, Antonio Trincone wrote:

> At first glance to this topic I browsed flickr site using chrome and did'nt
> see any difference like Gilles so what I figured out was a monitor issue or
> something like that; but now I compare flickr site using Firefox and chrome
> in two different windows and actually it is clear what Jim observed. Very
> interested in other possible examples also using jpeg produced by digital
> camera and not only scanned images.
> Antonio

Hello...

When Jim signaled the problem, I had a look at his images and I clearly
saw the difference. One image with good looking warm tones, and the other
a bit washed out and with a greenish overall tone.
(And I saw that with my Firefox 10.0.1)

After Antonio's e-mail, I've just did some extra tests and (maybe) found
something interesting :

1. I look at the Flickr image with Firefox, looks good

2. I download the image file on my computer then open the file with
    Gwenview. Looks greenish !

    (See my screen shot here : http://e-artefact.eu/scratch/screenshot-1.jpg
    The Firefox window is on the right of the screen, the Gwenview window
    on the left.)

3. More, I don't use the Flickr site any longer and open the downoaded
    image file from my disk, with Gwenview and with Firefox.
    (I.e.  gwenview <filename> &; firefox <filename> &)
    Same results, see my screen shot :
    http://e-artefact.eu/scratch/screenshot-2.jpg

So what :
    - Not a monitor effect, obviously, my screen is setup on sRGB color space

    - a viewer application effect, clearly. Antonio mentionned Firefox vs.
      Chrome, same with Firefox vs. Gwenview

I had a look at the (downloaded) image file. It embeds an ICC color profile
(Kodak ProPhoto RGB.)

I did and extra test by creating a new JPEG file from the downloaded image,
stripped from ALL what is not image datax (no more APP1, APP2 sections).
Then, the displayed image always looks greenish, whatever the viewer is.

My opinion :
Some applications (e.g. Firefox) are able to display a JPEG image, using
embedded color profiles, some (Chrome or Gwenview) aren't.

Probably, images for the web should be processed in a compatible way to
always provide JPEG data compatible with sRGB space, not relying on the
use of an embedded color profile.

If this could help Jim...

Regards,
Jean-François