Strategy for obtaining larger service image/file (isShownBy), from OAI-PMH feed (UCSC)

[aturner]

See cells R46 and R47 at https://docs.google.com/spreadsheets/d/1u2RE9PD0N9GkLQTFNJy3HiH9N5IbKDG52HjJ6JomC9I/edit#gid=265758929

Example record:
https://54.84.142.143/couchdb/_utils/document.html?ucldc/127--oai%3Acdm16019.contentdm.oclc.org%3Ap265101coll25%2F100

1. isShownAt:
   We'll have to fish out the URL to the object, which appears in one of the several source metadata dc:identifier fields, and gets mapped over to sourceResource:identifier. Example from the object above:
   http://cdm16019.contentdm.oclc.org/cdm/ref/collection/p265101coll25/id/100

2. isShownBy:
   Two ways to get at this:

• To generate a small thumbnail, replace "cdm/ref" (from isShownAt URL) with "utils/getthumbnail"
  http://cdm16019.contentdm.oclc.org/utils/getthumbnail/collection/p265101coll25/id/100
• Force CONTENTdm to provide a larger sized image, using this URL syntax. Plug in the collection number into "CISOROOT" and item number into "CISOPTR" (extracting those values from the isShownAt URL), and add the parameters:
  http://cdm16019.contentdm.oclc.org/utils/ajaxhelper/?CISOROOT=p265101coll25&CISOPTR=100&action=2&DMSCALE=125&DMWIDTH=512&DMHEIGHT=512&DMX=512&DMY=0&DMTEXT=&DMROTATE=0