[Digikam-devel] What do we want to store in the database?

[Arnd Baecker]

Hi Marcel,

I went through all the messages in this thread
and tried to compare with your DBSCHEMA.ODS
http://websvn.kde.org/trunk/extragear/graphics/digikam/DBSCHEMA.ODS?view=log

I have found a few points which are not listed
(very likely on purpose ;-), but let me still mention them here
(note that this list partially contains verbatim copies
from the original messages):

- Table Tags:
  - comments for tags
    (This would for example allow to provide additional information
     about a person, or animal, or landscape, ...
     I.e., something which would not make sense to
     add to the comment of each of the corresponding
     images, because it is just the same/generally applicable)
     http://bugs.kde.org/show_bug.cgi?id=149372
  - additional boolean flag: visible/hidden
    (i.e. all images tagged by a tag marked
     hidden are not shown, i.e. private images etc.)

- Grouping of images
  http://bugs.kde.org/show_bug.cgi?id=121310
  (Coming from panoramae, or bracketed shots for HDR).
  Within a group it should be possible to select
  which images are visible (i.e also more than one).

  This would also allow to group JPG and RAWs together
  http://bugs.kde.org/show_bug.cgi?id=147427

- And what about to Tag Album as well (to replace "collection"
  properties?) :
  http://bugs.kde.org/show_bug.cgi?id=133011

- ImageInformation or ImageMetadata (?):
  - technical quality tags
    http://bugs.kde.org/show_bug.cgi?id=128333

- Associate a region in an image with a tag:
  http://bugs.kde.org/show_bug.cgi?id=146337

  Note that such a region should not be a property of a tag,
  but a property of an image. Example:
  If there are several persons on one image, one can
  first add the Person's names as tags to that image  (as right now).
  In addition, one may mark the region of the face
  and associate it with the tag.
    Image:
    Tags: - Name1
          - Name2
          - Name3
    Regions: - Region1   --> Tag Name1
             - Region2   --> Tag Name2

  Not sure how to put this in the database scheme ...
  To specify the region: the simplest are rectangles,
  but one should also think of more complicated shapes
  (circle, ellipse, general svg paths) in the longer run.
  So it might be good to keep this in mind already when setting
  up the database scheme.

- Table ImageMetadata:
  - lens type (focal range in 35mm equivalent is available in Makernotes)
  - focus mode
  - macro
  - stabilization
  - focus point (can be quite camera dependent)
    http://bugs.kde.org/show_bug.cgi?id=138704
  - panorama mode
  - perhaps few original informations from pictures taken from camera as
    org. size, org. date, org. filename, cmaera serial number,  UUID of
    media, etc. to perform detection of already downloaded pictures for
    camera gui. This way is under discussion...

- Table GPS data
  - orientation (compass)
  - tilt (nb of degrees with regard to horizontal)
  - roll
  (I.e. to fully specify the position of an image in space,
   horizontal and vertical FOV have to be known, which
   can be obtained from the lense properties.
   and three angles for the direction and the two possible directions
   to tilt a camera in space.
   This can then be used to create photoverlays with googleearth
   http://code.google.com/apis/kml/documentation/kml_tags_beta1.html#photooverlay
   or make use of gipfel
   http://www.ecademix.com/JohannesHofmann/gipfel.html

- not sure about this one:

  Without giving it too much thought, I think a date may be a useful field
  to store too (thinking ahead to comments pulled in from external sources.

  I'd go for a table along the following lines:
  imageid INTEGER
  date DATETIME (optional)
  lang TEXT (optional)
  source TEXT (optional)
  author TEXT (optional)
  comment TEXT

- Another thing which may be important to store in the database is
  information concerning movies:
  length, frame number of the thumnail used, ....

Generell points:
- Only include displayable files in the database:
  http://bugs.kde.org/show_bug.cgi?id=145743

- Action lists:
  http://bugs.kde.org/show_bug.cgi?id=125387
  http://bugs.kde.org/show_bug.cgi?id=103350
  (presumably some more bugs ...)

Best, Arnd