[Digikam-users] digiKam and floating point tiffs and openexr files

[Elle Stone]

On 12/31/2015 01:52 PM, Gilles Caulier wrote:
>
>
> 2015-12-31 19:44 GMT+01:00 Elle Stone <ellestone at ninedegreesbelow.com
> <mailto:ellestone at ninedegreesbelow.com>>:
>
>     Krita, GIMP 2.0/2.10, Blender, the raw processors darktable and
>     PhotoFlow, and also other image editing software have the capacity
>     to open and save 32-bit floating point tiffs and/or openexr files.
>
>     I've accumulated a lot of such files in the course of editing
>     images, to the point where I'd like to find an image viewer for
>     browsing through the images and then opening selected images with
>     various high bit depth image editing programs.
>
>     As far as I can tell, digiKam can't read floating point tiffs and
>     also can't read openexr files. Would filing a bug report/enhancement
>     request be worthwhile?
>
>
> digiKam use a 16 bits color depth integer image data container to edit,
> which will solve 99% of photography case, including RAW files.
>
> floating point image data are very specific case, typically used in pro
> video for ex.

In the past, yes. But I suspect that over the next couple of years more 
and more photographers and digital artists will be editing 32-bit 
floating point images.

>
> You can load this kind of image in digiKam image editor through QImage
> loader, but in 8 bits per color per pixels. that all.
>
>
>     It would be nice if digiKam could be used to not only view but also
>     catalog and tag such images.
>
>
> Cataloging/tagging, etc, is not a problem here. Metadata management is
> delegate to Exiv2, which support TIFF, but not OpenEXR as i know. In all
> case XMP side car is the solution here. Also, no problem with database
> with these kind of image formats.

I put some sample files of various formats in a folder cataloged by 
digiKam, and refreshed the folder, and also closed and reopened digiKam:

The openexr file and the Krita KRA file both failed to show in digiKam.

The floating point tiff and the GIMP 2.9 XCF file both showed up, but 
without any actual image being displayed.

>
>
>     It would be extremely nice if digiKam could also be used to catalog
>     and tag high bit depth GIMP XCF files and also Krita KRA files.
>
>
> Supporting other color depth that 16 bits will be complex and long to solve.

Currently digiKam sort of supports PhotoShop PSD files, at least ones 
that were saved using maximum compatibility. By "support" I mean a 
thumbnail is shown in digiKam.

Would an embedded thumbnail of some sort maybe make it easier to enable 
support in digiKam for showing Krita KRA files and/or GIMP XCF files, 
not for editing with showFoto but rather displaying a thumbnail for 
cataloging and tagging with digiKam?

Elle