Support additional thumbnail resolutions

This feature requires license version 11.2 or higher.

Whenever a thumbnail is generated when a file is loaded into the Digital Assets module, the thumbnail will be generated in three resolutions:

• Name: small | resolution: 120px | suffix: '_st'
• Name: medium  | resolution: 240px  | suffix: '_mt'
• Name: large  | resolution: 360px  | suffix: '_lt'

This change coincides with the removal of Azure Cognitive Services 'Smart Cropping' feature. Instead, the source file resolution is scaled according to thumbnail resolution required, and the the source file's original aspect ratio will be preserved in the thumbnail.

The thumbnail pixel size will apply to the larger of the image's dimensions (e.g. if an image is 1000 pixels wide and 1200 pixels high, the small thumbnail will be 100 wide x 120 high).

In the Enquiry module,

• Brief Display sets will use the medium (240px) thumbnail
• record Full Display will use the large (360px) thumbnail

In the OPAC, the thumbnail to be used for Brief/Full Display may be configured using the Thumbnail size parameters in the Brief Display & Full Display sections of the OPAC HTML Configurator.