In some disciplines image comparison is an important approach for understanding different works. IIIF can help enable image comparison in ways other than just side-by-side viewing in viewers like Mirador.
You can use Leaflet to compare two images:
What do you see that's different.
Compariscope Example: X-Raying Balenciaga
Take a look at these x-rays of Balenciaga garments. Be sure to click on "enable x-ray" and then mouse over the image.
Compariscope Example: Hadleigh Castle
Hadleigh Castle by John Constable, 1776–1837, British
Below are links to a sketch and then a finished painting. By comparing these two paintings we can see how the painter changed the scene.
You can try these images in the Compariscope.
Here's a video of creating this kind of comparison:
And here's what the result for the user looks like:
Painting and Place
If you tour Arles, France, you can take the Van Gogh walk where reproductions of paintings are placed from the perspective of where they were painted. With IIIF it would be possible to do similar with tools like those above.
Van Gogh Walk links:
We'll see more later about how Mirador can be used for image comparison even with images across institutions.
Take a look at how the Boxwood Project from the Art Gallery of Ontario uses Mirador to compare objects.