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CDS2 Developer Guide

CDS2 Developer Guide

Owned by Seong-June Kim
Last updated: May 19, 2021
6 min read



Getting Object Information

Manifest

https://manifests.collections.yale.edu/{unit}/{object_type}/{object_id}

object_type corresponds to assets.cmstype in the TMAN database and object_id to assets.cmsid.

Example:

https://manifests.collections.yale.edu/ycba/obj/38803

https://manifests.collections.yale.edu/yuag/obj/211386

https://manifests.collections.yale.edu/ypm/nat/2

Getting IIIF Images

IIIF image info

https://images.collections.yale.edu/iiif/2/{unit}:{uuid}.tif/info.json

Example:
https://images.collections.yale.edu/iiif/2/ycba:c5bad9c0-24f7-482c-9852-f6a554a4314a/info.json

IIIF image

https://images.collections.yale.edu/iiif/2/{unit}:{uuid}.tif/{region}/{size}/{rotation}/{quality}.{format}

For detailed explanations for parameters region, size, rotation, quality, and format, please refer to IIIF Image API.

Example:

Full(max) size image: https://images.collections.yale.edu/iiif/2/ycba:c5bad9c0-24f7-482c-9852-f6a554a4314a/full/max/0/default.jpg
Width 280: https://images.collections.yale.edu/iiif/2/ycba:c5bad9c0-24f7-482c-9852-f6a554a4314a/full/280,/0/default.jpg
Height 280: https://images.collections.yale.edu/iiif/2/ycba:c5bad9c0-24f7-482c-9852-f6a554a4314a/full/,280/0/default.jpg
Crop x=500, y=400, width=500, height=480: https://images.collections.yale.edu/iiif/2/ycba:c5bad9c0-24f7-482c-9852-f6a554a4314a/500,400,500,480/max/0/default.jpg

Private image (Unit Access Only)

Attach a JWT to the request as the Authorization header. To encode it, each unit will share a “secret” (see ENV['YPM_SECRET'] in the code below) with ITS.

Send an API key to the request as a bearer token in the Authorization header. Each unit will share an API key (see ENV['YPM_SECRET'] in the code below) with ITS.

A curl example:

with TOKEN replaced with the actual value of the API key

An example in Ruby:


Getting Stock TIFF Images

Example:
https://media.collections.yale.edu/tiff/ycba/c5bad9c0-24f7-482c-9852-f6a554a4314a.tif

Ingest of Images and Image Data

TMAN Database

  • production: traffic-manager-prd.cnh4zslmvwh7.us-east-1.rds.amazonaws.com:1433

  • development: traffic-manager-dev.c7exm1chla3f.us-east-1.rds.amazonaws.com:1433

New Database Fields

  • cds_access_master (type string, default: N): N (no access) or P (public)

  • cds_access_tiff (type string, default: N): N or P

  • cds_access_jpeg (type string, default N): N, U (unit access), or P

  • cds_maxsize_tiff (type integer, default: 0)

  • cds_maxsize_jpeg (type integer, default: 0)

Rules on Max Sizes

  • If max size is not specified or the value is 0, the image will maintain its original size.

  • If max size is bigger than the original size, the image will maintain its original size. 

Image Conversion to Pyramidal TIFF

  • Pyramidal TIFF contains copies of the original image at various scales. 

    • Each copy is created using JPEG compression at the quality level of 90%.

  • Images are converted to the ICC color profile "sRGB IEC61966-2.1".

Image Conversion to Stock TIFF

  • Images are converted to the ICC color profile “Adobe RGB 1998”.

Results

Result from processing each content is gets saved to TMAN database columns assetstatus.cds2_status and assetstatus.cds2_error.

The possible values for cds2_status are:

507

Image processing was successful. Manifest builder has been notified to update the manifest for the content.

607

Image processing failed.

807

Image processing was successful and the manifest for the content has been updated.

907

Image processing was successful but manifest build failed.

 

Ingest of Object Data via Activity Stream

Metadata for objects to be delivered in the form of IIIF manifests gets harvested by CDS2 harvester. Each unit should implement an activity stream for that. We will use a subset of the protocol defined in IIIF Change Discovery API.

Note

  • The stream is to be published via HTTP(s).

  • As long as it follows the API, the implementation detail is not important. For example, it can be an application that accommodates HTTP GET requests, or it can be a set of files served from an HTTP addressable store such as S3. 

  • All data to be downloaded and parsed by the harvester MUST be encoded in UTF-8.  

Collection

A collection is the highest level document that (recursively) contains links to all other necessary documents. The harvester only has to know the URL of the collection.

Example

Attributes



 



 

id

All "id" attributes in the activity stream must be an actionable URL for the resource

first

Points to the first page document (in time order)

last

Points to the last page document

Page

Example

Attributes



context

description



context

description

type

under "orderedItems"

Type of activity. Must be “Create”, “Update”, or “Delete”. For practical purposes, “Create” and “Update” are handled in the same way and won’t make any real difference.

type

under "object"

Type of the payload (the object that changed).
"lido" for YUAG, "json" for others.

endTime



Timestamp of the activity. The page document must list the activities (in orderedItems) in order, sorted by endTime (earlier activity goes first). 


The time values for the “endTime” attribute should follow the format “YYYY-MM-DDThh:mm:ssTZD”, a.k.a. RFC3339 or ISO 8601.

For example, “3:25 p.m., December 4, 2019, EST”, should be presented as “2019-12-04T15:25:00-05:00” or  “2019-12-04T20:25:00Z”.

 

Payload

Document ("object") referenced by an activity item in the page document. It contains the real data for the object in question.

Example

Attributes



 





 



unit, cmsType, cmsId

 

These three values together uniquely defines an object, corresponding respectively to unitcode, cmstype, and cmsid in the dbo.assets table of TMAN database.

metadata

 

  • An ordered list of items, each of which has a "label" and a "value".

  • All entries are optional, except "label", "logo", and "Attribution" are required.

  • Any combinations of “label” and “values” can be added here, and each item will be added to the top level “metadata” field of the manifest as it is, with the exception of the “special” labels below, which are interpreted differently.

label

becomes the “label” for the whole manifest

 

Rights URI

goes to the top level “rights” field

 

Rights Description

goes into the top level “requiredStatement” field

 

Copyright Statement

 

 

Image Use Rights URI

 

 

Image Use Rights

 

 

logo

goes to the top level “logo” field

 

homepage, seeAlso

goes to the top level “homepage”, “seeAlso” field respectively. Since these can have great variability among units, this field should be entered verbatim as should appear in the manifest, according to the API. See

 




 

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