[KPhotoAlbum] kphotoalbum method of storing Tags, description

[Andreas Neustifter]

Hi All!

On 30 January 2012 07:22, Miika Turkia <miika.turkia at gmail.com> wrote:
> On Mon, Jan 30, 2012 at 2:24 AM, Karl Schmidt <karl at xtronics.com> wrote:
>> On 01/29/2012 12:50 AM, Miika Turkia wrote:
>>
>> It might not be trivial to write the code to add annotation to a picture,
>> BUT I am absolutely certain it can be done without corrupting the image.
>> <time passes>  I just did it with digikam and verified that it is in the
>> file with exifprobe - all the camera data is intact.
>
> There is no question whether it can be done or not. We used to have
> that feature and might have it also in the future. It just needs some
> developer to pick up the task and code it up (any volunteers?).
> However, internally KPA will still use own "database" as reading tags
> from one file is many times faster than scraping the tags from tens of
> thousands of files and many of our users prefer not touching the
> original images at all.

Some toughts:

I see no way of getting rid of the XML database for several reasons,
not the least of which are speed, reliability and well working and
tested code.

EXIF data is usually read only and contains all the settings and
meta-data that the camera records when taking a picture. Usually
editors should strive to preserve this data, maybe modifying the "last
edited" date, I see no issues for KPA there.

IPCT and XMP are used to store other information (places, people, ...)
and both can be embedded in the files themselves.

I guess KPA could either continuously write XMP and IPCT to the
pictures as well as to the XML-DB (less likely IMHO) or there could be
a "export" dialog including a big fat "backup your files
first"-warning that writes the current tags to the images.

(Just as a side note: It would be best to architect those exports as
"plugins" with a defined interface so that they can be implemented
separately with the help of the appropriate libraries. But that maybe
talking to much into the future...)

Importing from IPTC and XMP should be done on detecting new images or
changes to present images.

What would be quick, fast and easy would be a python script that just
exports from XML-DB to XMP and IPTC, btw.

Andi