On the digital collections homepage, we showcase a series of “featured topics” (also known as “homepage categories”.) As of 2021, we have nine of them: “Women in Science”, “Instruments and Innovation”, and so on.
When we create a new one, a curator typically provides the developer with a thumbnail cropped from an original TIFF chosen from the digital collections.
Instructions for the curator
To create the thumbnail:
Download a high-resolution original TIFF from the digital collections.
Crop the TIFF so that the resulting file is a square at least 700x700 pixels on each side. (Bigger is fine)
Assume the bottom sixth of the image will be hidden by the label displayed in front of the thumbnail.
Place the cropped TIFF in:
P:\Othmer Library\Digital Collections - External Access\Crops for Hydra Redesign\cropped_tiffs\categories
Instructions for the developer
Use the following imagemagick command to convert the thumbnail to a jpg:convert original_file.tif -density 600x600 -resize 700x new_thumbnail_2x.jpg
The resulting thumbnail checked into the codebase should be:
a jpg
600x600 density (we aren’t totally sure why this matters, but think it’s what we’ve been doing)
progressive JPG (displays better while in process of being loaded by browser)
700 pixels wide x 700 pixels tall (we have a 350pixel spot on the page, and want double density to look good on high-res displays)
with a name ending in
_2x.jpg, consistent with the other files in the featured topics asset directory.
See also
For more technical information on featured topics, see: app/controllers/featured_topic_controller.rb and app/views/homepage/_featured_topics.html.erb .
For examples of past Github issues relating to these, see e.g. water, portraits and people, women in science, and so on.