One of the reasons for going with Piwigo was I thought I could pull off using metadata (with maybe custom fields) to store basic information within the photo itself making the image "portable" for use in other locations like wordpress.

Here is a use case I want to realize.   

Photos are edited any number of places like any of the desktop (e.g. pyexiftoolgui in linux) or mobile programs that can edit meta data and maybe within piwigo itself.   

In the meta data at the minimum a photo will need these fields (some of which already exist or can be re-purposed within the default fields)

1.  Title
2.  Caption
3.  Date
4.  Extended Description (for say a slideshow)
5   Location
6.  Project Name
7.  Base-Album Name
8.  Tags/Keywords
9.  ....

These could be edited/viewed within any program including piwigo.     Then in say wordpress I can set up shortcodes to extract selected information for display with the photo.  For example the caption.   

Having this basic information be stored within photo is pretty critical to our non-profit.  We have people taking pictures across the globe with and without internet available that need to get particulars down right then not later when they finally get to be part of a database.  This also makes the pictures portable and self-contained if they get pulled away from the db or db gets trashed, etc.

So I already have the write Metadata plugin loaded which is a big help!! with syncing meta data with db.

My questions are

1.  How to view/edit the exiting IPTC fields within piwigo?

2.  How to make/read/write custom fields within piwigo    (well at least how to read custom fields made elsewhere)

3.  Is IPTC metadata the best place or is XMP better used and supported for these fields .  As far as I can tell XMP is the better place and IPTC is the older standard.  In which case is the write MetaData plugin is useless?  Or if I can do my own custom fields does it matter.


Specifics are great, general strategy/advice appreciated, especially if someone has already come up with this use caseon and has tried to implement such.

thx, David

Piwigo version: 2.7.4
Environment

        Operating system: Linux
        PHP: 5.5.9-1ubuntu4.7 (Show info) [2015-04-07 19:36:00]
        MySQL: 5.6.23 [2015-04-07 19:36:00]
        Graphics Library: ImageMagick 6.7.7-10


Piwigo URL: http://photos.healthwrights.org