Rethinking Tags

[m.Th.]

In the DB we have the table 'Images' which has for each image the field 'Tag' of type INTEGER.

However, the architecture isn't very good. Since 'Tag' is a sparse field (ie. very few tagged files in a sea of untagged ones) the best solution would be to move the 'Tag' field in another table to hold only the tagged files.

Benefits: (Much) faster. Allows the implementation of 'Albums' or 'Projects' (more or less temporary collections which usually users create for different purposes). A neat feature present in Lightroom, Zoner Photo Studio and IDImager.

However, in a catalog with 22598 images (mine) with the current architecture it works ok.

What do you think?

[xnview]

Something like ImageID, Tag

[oops66]

+1, ... Yes, good suggestion and "product improvement" too

[m.Th.]

Something like ImageID, Tag

Yes, sort of.

Database layer:

I will speak in SQL (not tested):

Code: Select all

-- first we'll create the Albums

Create Table Albums (AlbumID Integer Primary Key Autoincrement, AlbumName Text Not Null Unique);
Insert into Albums values(null, 'Tag'); -- the 'null' here will became 1 due of autoincrement. Do also a trigger or use the GUI to disallow the delete operation on this item

-- and now we'll use them in DB

Create Table AlbumsLink (AlbumID, ImageID, UNIQUE (AlbumID, ImageID));

Create Index Albums_ImageID_idx on AlbumsLink(ImageID);

Presentation (GUI) layer:

When one will tag/untag a photo, you will add/delete a record with the respective ImageID and AlbumID=1 (magic value)

Albums management

For the other albums you can have

1. a simple list like in Lightroom when you'll add/rename/delete albums (aka Collections in Lr terminology)

- or -

2. an entire browser like in Zoner Photo Studio:

ZPS.PNG (50.75 KiB) Viewed 1457 times

- or -

3. tabs at the bottom of the form like in IDImager (you can see also the right-click management menu)

IDI.png (11.51 KiB) Viewed 1457 times

Also, IDImager implements the notion of the temporary album which is emptied at the end of session (as you see, it is called Image Basket - someting similar can be configured in XnViewMP with Tags)

Of course, as I said, you will take care to show in your GUI metaphor only albums which have AlbumID>1 (ie. Select AlbumName from Albums where AlbumsID>1 order by AlbumName).

Photos management:

In each case adding a photo to an album/collection is done by dragging the selected file(s) over the list item/folder/tab.
Removing the photo is done by having the collection selected and chose from the right-click popup menu the "Remove selection from the current collection"

HTH

[oops66]

...Also, IDImager implements the notion of the temporary album which is emptied at the end of session (as you see, it is called Image Basket - someting similar can be configured in XnViewMP with Tags)

... And it's sorted by default by the "EXIF date taken" (or if not : XMP, or IPTC, or creation date,...) probably, for having a pertinent chronology ... no ?

[m.Th.]

...Also, IDImager implements the notion of the temporary album which is emptied at the end of session (as you see, it is called Image Basket - someting similar can be configured in XnViewMP with Tags)

... And it's sorted by default by the "EXIF date taken" (or if not : XMP, or IPTC, or creation date,...) probably, for having a pertinent chronology ... no ?

As you wish. Usually these systems are working like this (adapted for XnViewMP ):

1. The user clicks on the Temporary Album. (by convension the Temporary Album(s) take internally negative IDs in order to be easily wiped by delete from AlbumLinks where AlbumID<0)
2. Extract IDs from DB (in my proposal Select ImageID from AlbumLinks where AlbumID=-1) in a comma list string (let's call them imgIDs
3. Extract EXIF - Select Meta from Images where ImageID in (imgIDs) - and based on this build my own internal data structure (usually a linked list/collection of objects with all the values in place)
4. Extract the thumbs - Select Data from Datas where ImageID in (imgIDs) - see why it is very good to have different DBs for metadata and thumbs?? This could be run in parallel.
5. Sort the in-memory structure from step 3 according with GUI settings.
6. Render / Display

AS YOU SEE ON STEP 5 it is entirely upon you how to display this.

As an aside, yes, I have the default setting in my thumbnail browser in almost all DAMs the 'EXIF date taken".

PS: Pierre, if you do something else compared with the steps above then perhaps you can have performance penalties. Especially if you issue more queries that above. Tell me and I'll have a look.

[xnview]

Ok, i'll change tag for 0.57, and will add albums in a future release