[Digikam-devel] raw problems

[Guillaume Castagnino]

Hi,

For your 16bits test, patch will NOT solve the dark image issue :
To change this, you will have to use a good ICC profile.
For example here : 
http://digikam3rdparty.free.fr/ICCPROFILES/CameraProfiles/BBP.4.9.5/

I see you have a Canon camera :
To use the right profile, I have this table for Canon (not complete 
but...) :
Canon EOS 10D  canona.icm
Canon EOS 20D  canon9.icm
Canon EOS 300D  canona.icm
Canon EOS 350D  canon9.icm
Canon EOS 400D  canone.icm

Applying the good icc profile will lead you to a well exposed image in 
16bits mode ;)

Regards,
Guillaume

Le mardi 4 septembre 2007, Arnd Baecker a écrit :
> Hi,
>
> I was about to test the patch
> http://bugs.kde.org/show_bug.cgi?id=142055
> but before I wanted to look at that current status
> to see the difference.
>
> There are various problems in the following situation:
> Take the same image in the two versions RAW and JPG
> (as they come out of the camera, Canon EOS 350D for this example),
> with no color management enabled.
>
> Tests A:
> "RAW Files Decoding Settings"
> - 16 bits color depth
> - interpolate RGB as four colors
> + White balance: "Use camera white balance"
> + Automatic color balance
> + Highlights: Solid white
> + Brightness: 1.0
> + Interpolation: Bilinear
> - noise reduction
> - enable chromatic aberrations
>
>
> Tests A - results for the comparison of RAW vs. JPG
> ---------------------------------------------------
>
> - the thumbnails look very similar
>   (the histogram of a screenshot for each thumb
>    show only a small variation)
>
> - The histogramms for RAW and JPG differ considerably
>   (for the raw one all its weight is near small values).
>
> - BUG:
>   first going to the CR2 is fine, histogram is computed
>   (takes long!) and shown.
>   Then go to JPG - ok.
>   Then back to the CR2 - the "Histogram" TAB says
>   "Loading image" and this never finishes.
>   (will file a separate BKO for this)
>
> - Then, in preview mode (Setting: extract embedded preview)
>   going back and forth between JPG and RAW
>   one sees that RAW and JPG differ in width slightly
>   (Colors etc. are essentially identical)
> - With setting:  "Embedded preview load full image size"
>   the colors are different
>   (the raw one appears much more green).
>
> - Loading the images into the editor,
>   they look pretty much like
>   those from the preview (when "Embedded preview load full image
> size" is activated), i.e. the raw one appears much more green.
>
>
> Tests B - results
> -----------------
>
> change in the setting:
> + 16 bits color depth
>
> Everything as in A), but:
> In image editor: in 16 Bit: almost dark image
> (which corresponds to the histogramm seen before ;-)
>
> With patch
> ----------
>
> Applying
> http://casta.nerim.net/digiKam/digikam-kde3-WB-ufraw-multiplier.patch
> (which did not change anything?)
> and
> wget http://casta.nerim.net/digiKam/libkdcraw-kde3-dcraw-WB.patch
> wget http://casta.nerim.net/digiKam/digikam-kde3-dcraw-WB.patch
> wget http://casta.nerim.net/digiKam/kipi-plugins-kde3-dcraw-WB.patch
>
> Hmm, I don't see a different behaviour compared to A).
> So presumably I am looking for an effect at the wrong place
> (Just showing off that I haven't understood how to work with
> raw under digikam ...;-)
>
> Best, Arnd
> _______________________________________________
> Digikam-devel mailing list
> Digikam-devel at kde.org
> https://mail.kde.org/mailman/listinfo/digikam-devel



-- 
Guillaume Castagnino
    guilc at laposte.net / casta at xwing.info
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