bin image mosaic limited to 20 pages

[srstsavage]

The image mosaic is currently hard limited to 20 pages:

https://github.com/WHOIGit/ifcbdb/blob/d35d943c573eb3c0162b47f1b44ed5b496b178fb/ifcbdb/dashboard/tasks.py#L33

As a result not all images are shown in large bins unless users select a larger View Size for the mosaic. Can this limit be eliminated or made configurable?

https://github.com/WHOIGit/ifcbdb/commit/968f89dc499293f08d105516170fdc254edd8278

[joefutrelle]

The rationale here is to prevent expensive computation of pages that have limited if any value to users--which would make rendering the first (and most valuable) page slower. By limited value I mean that those later pages contain large numbers of ROIs that are so small that they are unidentifiable. The trade space here is the user's time, their screen real estate, and their cognitive load.

[joefutrelle]

@shane-axiom feel free to point me to bins in any of your dashboard instances where this limitation is problematic--it looks like you were already hitting the problem of concentration estimates overflowing the y-axis on the plot.

I also want to draw your attention to #351 -- there are known issues with the current mosaic algorithm so fixing them is an opportunity to tweak things if new use cases are coming up.

[srstsavage]

We're hitting these issues on the Bodega Marine Lab IFCB:

https://ifcb.caloos.org/timeline?dataset=bodega-marine-lab&bin=D20220609T172057_IFCB163

The rationale for limiting the pages makes sense, but it would be nice if there was some kind of indication that the number of pages were truncated, maybe with a hint about expanding the View Size to see more...

[joefutrelle]

Thanks, it's helpful to see that and it's certainly not something I've seen before--where 20 pages in at default view settings there are still large ROIs. Agreed that having no indication that a page limit has been exceeded is a problem and that viewing the last few pages is likely to be useful when dealing with data like this--probably more useful than reviewing one of the many intermediate pages.

Plotting is also designed to help with some of these user tasks like "what do the smallest images look like"