The Harvard Library Viewer is a new image viewing platform based on the open source Mirador project and compatible with the IIIF (International Image Interoperability Framework) standard. Harvard Library Viewer provides access to book-like digital objects (manuscripts, broadsides, photograph albums, musical scores, etc.) hosted by the Harvard Library Digital Repository Service (DRS) or any other repository that is IIIF-compatible. 

What functions are available? 

Besides core page-viewing capabilities such as page-turning navigation, table of contents, full text search and print (PDF download), the Harvard Library Viewer implements frequently-requested features, including:

• Two-page and scroll views
• Improved page image rotation, zooming and panning
• Comparison of IIIF-compatible documents
  

And the new Viewer is a platform that can be expanded in the future to support new capabilities for research and teaching, such as annotation and document portfolios, as well as expanded comparison of compatible text and images from collections at Harvard and internationally.

Switching between the Viewer and Old PDS

The new Viewer interface will automatically display for page-turned objects discovered through Harvard Library catalogs and websites. For the time being, access to the old Page Delivery Service (PDS) interface will remain available via a "View in PDS" link in the Viewer top menu.

Large documents and serials with 5000 pages or more will continue to display in the old PDS interface for now, until migration to PDS list objects is complete.

Navigating an object

This screenshot shows basic options for navigating pages in an image object. Click the image to enlarge.

Changing the view of an object

This screenshot shows options for how an image object can be displayed. 

Searching the full text of an object

Search terms may be combined using the following operators:

and or not near

The default operator is "and", so the following two queries produce identical results:

harvard yard
harvard and yard

which will only match documents that contain both of the terms "harvard" and "yard".

The and operator will match terms that occur anywhere in a document. To search for a phrase, enclose it in quotation marks:

"harvard yard"

which will only match documents containing the phrase "harvard yard".

The near operator will match terms that are within 100 words of each other, regardless of their order.

Tip: Use * as a wildcard. Examples: cat*, oper* and Harv*

Viewing multiple image objects

You can use the Viewer workspace to compare multiple image objects. This can include image objects at Harvard or external sources, as long as they come from a IIIF-compatible repository. At this time, page-turned objects stored in DRS and delivered by the Harvard Library Page Delivery Service (PDS) are IIIF-compatible. 

In this release of the Viewer, compatible image objects can be loaded directly into the viewer if you know the object’s manifest url. This url retrieves a manifest – a collection of presentation and structural metadata that the Viewer uses to display the object.  (A future release will let you search for compatible image objects.)

For DRS page-turned objects, the manifest url format is:

http://iiif.lib.harvard.edu/manifests/drs:[DRS_ID]

E.g., http://iiif.lib.harvard.edu/manifests/drs:50230073

To load another object in the Viewer:

See the next section for a list of compatible image objects to try out in the Viewer.

1. Click the Change Layout grid icon (in upper left corner of workspace). Add a new slot in your preferred location (right, left, above or below the current object).
   
    
   
   Or, click the "Change Layout" option (in upper right corner of workspace). Click into the grid and drag to select the number of slots you want.
   
   
    
2. A new slot containing "Add Item" will display. Click the plus sign to open an object selection page.
3. Insert the manifest url of the new object into the "Add new object from url" box. Press Enter and the object will be added to your selection list.
4. Click your selection to open it in the new slot.
5. To increase viewing area for each image, you can minimize the Table of Contents column. To minimize, click the down arrow above the Contents column.

Note that objects added in this way will remain on your selection list during the current Viewer session but cannot be saved for future sessions.

To close an additional object slot:

1. Click the Change Layout grid icon (in upper left corner of workspace). 
   
   
    
2. Click the x Close option and the slot will disappear (but the object remains on your selection page).

Sample compatible objects

Here are sample IIIF-compatible image objects at Harvard and other repositories that you can open in the Harvard Library Viewer. For Harvard objects, use the "Viewing URL" in a browser and use the "Manifest URL" when loading a new object into an existing Viewer session. 

Harvard page-turned objects

Compatible objects from external repositories