• Article Type: General
• Product: Primo
• Product Version: 3

Desired Outcome Goal:
Create Primo thumbnails from the jpegs (access files) not the preservation master files.

Procedure:
1. The algorithm for selecting a REP (representation) for thumbnail generation is as follows:
Derivative copy
REP with no AR (access rights)
Any other REP

If there is no derivative copy, the system will create thumbnails from the first REP it encounters that does not have any AR.
If all REPs have AR, then it will select a random REP.

2. To control the REP from which thumbnails are generated, do one of the following:
a. Create a derivative copy
b. Set the AR (i.e. "everyone") on all REPs except the REP to be used for thumbnail generation.
The METS structmap determines the order of the thumbnails, not the REP to use for thumbnail generation.
The intention is to minimize thumbnail delivery failure due to AR.
The assumption is that derivative copies will always have the lowest level AR and will likely be the smallest (i.e. fastest) thumbnail generation, and if not, Rosetta will try to find a REP without AR, etc.
Note that all IEs require an AR policy; but REPs do not.
Thus, there is no difference between a REP with no AR policy and a REP AR (i.e. "everyone").
If a REP has AR and requires thumbnail generation, one might consider removing the AR from the REP, especially if it's "everyone".

3. To remove the AR from the REP, create a task chain with an "Un-assign AR Policy from Representations" task (parameters below):
Preservation Type: Modified Master
Label (optional)
Representation Code: None
Representation Entity Type: None
Rosetta will likely try to match on all three, assuming these IEs are created uniformly.

If METS with REP AR are not being created (or assigned during enrichment), they won't have any AR.
There's no inheritance on an AIP level, although from a functional aspect there is, since delivery must pass IE AR before REP AR are checked.
If an IE has no REP-level AR, there's no way to control which REP the system picks up first.
In this case it's recommended to assign AR (i.e. "everyone" or otherwise) to the REPs that won't be used for thumbnails (or, create derivative copies).