[Digikam-users] Timeline view: creation vs modification date

[Gilles Caulier]

2008/5/22 Marcel Wiesweg <marcel.wiesweg at gmx.de>:
>> Hello everybody,
>>
>> when working with the timeline view (in the current svn kde3 version), the
>> tool selects those pictures which were last changed in the entered time
>> interval. However, I would rather like to select those pictures which were
>> taken in the selected time range (and maybe modified later). Is it possible
>> to configure this somewhere?
>>
>> Best, Gandalf
>
> In the KDE3 version we have only one "date" field in the database, usually
> creation date I think but I am currently not familiar if there are cases
> where this is the file system modification date.
>
> In the upcoming KDE4 release, we will have three distinct date fields: File
> system modification date, metadata creation date and metadata digitization
> date. The timeline tool is then based on the creation date.
> The metadata field for finding out this date are, in order, which field is
> found first:
>
> Exif.Photo.DateTimeOriginal
> Exif.Photo.DateTimeDigitized (*)
> Exif.Image.DateTime
> Xmp.exif.DateTimeOriginal
> Xmp.exif.DateTimeDigitized (*)
> Xmp.photoshop.DateCreated
> Xmp.xmp.CreateDate
> Xmp.tiff.DateTime
> Xmp.xmp.ModifyDate
> Xmp.xmp.MetadataDate
> Iptc.Application2.DateCreated
> Iptc.Application2.TimeCreated
> Iptc.Application2.DigitizationDate (*)
> Iptc.Application2.DigitizationTime (*)
> File system creation date
>
>
> (*)
> Gilles:
> I am wondering if e.g. Xmp.exif.DateTimeOriginal should not have priority over
> Exif.Photo.DateTimeDigitized if we are explicitly looking for the creation
> date, and not the digitization date. Perhaps we split out a method
> getCreationDateTime(), and then getImageDateTime() first calls
> getCreationDateTime() and secondly getDigitazationDateTime()?

Following the Exif spec, DateTimeOriginal and DateTimeDigitized must
be set at the same value.

But this is not the case with all camera. I have seen several cases
parsing my huge photo repository:

1/ DateTimeOriginal = DateTimeDigitized
2/ DateTimeOriginal is only set in Exif
3/ DateTimeDigitized is only set on Exif
4/ DateTimeOriginal and DateTimeDigitized are not available (and a
private tag is set on Makernote (why ???)
5/ DateTimeOriginal and DateTimeDigitized are null date (00:00:00
01-01-1970) => camera clock failure

But in all case, i have never seen DateTimeOriginal != DateTimeDigitized

This way can be follow with XMP exif tags of course, but i don't know
a camera which set XMP metadata.

Best

Gilles