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

[Mikolaj Machowski]

Dnia środa 29 sierpień 2007, Marcel Wiesweg napisał:
> Hi,
>
> It is a long-planned task for the next release to store more information
> than currently in the database.
> We are currently collecting which fields exactly we want to add.
>
> To qualify for inclusion, IMO a field should fulfill one of these two
> criteria:
> - the field can be of interest in connection with the image it belongs
> to - searching for the field is a considerable feature
> AND this criterion:
> - the information is usually available for images in a common usage
> pattern of digikam

I think we can split all data about image in 3 parts:

- information about file
- information about image ("hardware")
- metadata, here I think the best choice (as industry standard) is "IPTC
  Core"
>
> Currently I have these fields on my list:
>
> - comment
> - rating
> - creation date
> - modification date
> - size ( dimensions in pixels)
> - color depth (8, 16)
> - color model (RGB, CMYK, ...)

- If px size is included why not weight (size in KB/MB)? I know it can
  be read from filesystem but putting info in db could make some queries
  faster
- all path related things (Album path, name of file)

> - make of the camera
> - model of the camera
> - aperture
> - focal length
> - focalLength as for 35mm film
> - exposure time
> - exposureMode
> - exposureProgram
> - sensitivity
> - flash
> - whiteBalance
> - orientation

- metering mode
- focus mode
- file number (although it can have different formats so its usefulness
  can be questionable)
>
> - GPS:
>  - latitude
>  - longitude
>  - altitude
>
> - similarity searching with a Haar-like algorithm matrix
>
>
> Not included is compression, as no real information for this is availabe
> from the low-level libs for most image formats (nothing for jpeg,
> nothing for png)
>
> There was a discussion about multiple comments; what is the status about
> this?
>
> Do we want to store make/model as strings for each entry, or use a
> dedicated table "Cameras"?
>
> If you have remarks and additions, now is the time!

Big question is handling of metadata. I'd like to see whole IPTC Core
put into database... For fast querying of those items and making it
independent of actual images.

m.

ps. Disclaimer: I work in photo department of big museum in Poland
    and my primary responsibility is dealing with management of
    digital photographs and digital versions of analog materials.
    Usually my comments, wishes, etc. are biased from that
    perspective. I'd really like to use Digikam in my work :)