Categories and XnView.db usage and portability

[bryandrenner]

I'm evaluating XnView MP, and I'd like to know a bit more about XnView.db, especially with regard to maintaining a categorized photo library that can be backed up and restored easily. I'm aware of the "Export DB Category to XMP Subject and IPTC Keyword" setting. My questions are as follows:

- After I assign a category to an image, when does it get written to the image file?
- After I assign a category to an image, why doesn't the category appear in the dialog when I choose "Edit IPTC/XMP"?
- When does information about a particular image file get recorded in the database? For example, does information about an image get stored the moment I browse to its folder? Or after I first click / preview the image? Or after I first open the image? Or after I make a change to the image metadata?
- I noticed that the database seems to have entries for a lot of folders and files I've never browsed to in the application. For example, I see folder and file entries for random bits of my music library. How does XnView MP decide what files and folders to record in the database? Is there a way to limit it to a specific folder?
- Is there a way to have the database track images using relative file paths? I'd like to configure a base path as the root folder of my image library, but leave open the possibility of moving the whole library to another folder or machine. If the database tracks each file using an absolute path, this could be perilous, especially for backup-and-restore.

[michel038]

Hi briandrenner

- After I assign a category to an image, when does it get written to the image file?

-select an image, assign a category, release selection ...
Then, database is updated, and depending on settings in "Tools, settings metadata", iptc or xmp keywords will be created or updated

- After I assign a category to an image, why doesn't the category appear in the dialog when I choose "Edit IPTC/XMP"?

A "category" in Xnviewmp is a tool used to write keywords and update database.
The "Edit IPTC/XMP" window reads only IPTC metadata, or only XMP metadata depending on the first word chosen in "Option", "Mode" box.
And "IPTC Category" is an old metadata that no one uses anymore.

- When does information about a particular image file get recorded in the database?
For example, does information about an image get stored the moment I browse to its folder?

Yes, only if option "Import XMP subject or IPTC keyword to DB Categories" is enabled (Tools, options, metadata)
You can also : select a set of images, and click in "View, Update catalog from files"

Or after I first click / preview the image? Or after I first open the image?

no

Or after I make a change to the image metadata?

With "Edit IPTC/XMP window ? I'd like the author answers this question

- I noticed that the database seems to have entries for a lot of folders and files I've never browsed to in the application. For example, I see folder and file entries for random bits of my music library. How does XnView MP decide what files and folders to record in the database? Is there a way to limit it to a specific folder?

I never found folders that were not browsed, in my database ...
You can manage folders in "Tools, Options, Catalog" (Add, delete, Excluded/Included tab ...)

- Is there a way to have the database track images using relative file paths? I'd like to configure a base path as the root folder of my image library, but leave open the possibility of moving the whole library to another folder or machine.

There were some bugs with "Tools, settings, catalog" "Base path" field in previous versions.
I dont know if all problems are solved in new version.

If the database tracks each file using an absolute path, this could be perilous, especially for backup-and-restore.

Yes

In "Categories" panel, there are some useful tools (the small black down arrow)
- Categories management, export categories file ... creates a TXT file with only the names of categories : it's your "keywords dictionnary" ou "thesaurus"
-"Files's categories, Export" . This one creates a XML file with filenames and their location, and categories linked. Very interseting...
It's a way to backup categories DB. But stars and color labels are not saved. You can edit this file with a notepad.

Instead, you can copy xnview.db file. It's a whole backup of DB.