Increase max image size (from 2048 x 2048 pixels)

[tiwane]

We took a look into this recently.

@markg729

Since bandwidth and hosting costs are now free (https://www.inaturalist.org/blog/49564-inaturalist-licensed-observation-images-in-the-amazon-open-data-sponsorship-program/ ) for iNat photos under CC licenses, those CC photos could be stored at higher resolution with no additional cost to iNat except for development cost of enabling different sized uploads.

Using different sizes/quality for licensed or non-licensed images was deemed too complicated and would create problems if, say, someone changed their default photo license from a Creative Commons license to all rights reserved.

@bsteer

In general I would say it is better to increase the JPG compression rather than decreasing the resolution, but ideally this should be on a sliding scale such that the higher resolution, the more compression is applied (i.e. the lower the JPG quality setting is set)

Currently we use 99% quality for image compression, and I can’t tell the difference between “original” size large images I’ve posted to iNat and 100% 2048px quality jpeg exports from my photo software. If we used 100% quality for our image compression using the current method (not JPG XL), it would increase file size by over 28% with little to no bump in image quality. Increasing image size to 3072px on the log size doubles the image size, using our current method.

@bsteer

JPG XL looks like the best option here since it can be freely converted back to JPG again without any quality loss.

We didn’t test this out but we did test out webp compression. An image with 3072 px on the long side would be 9% smaller than the 2048px images we have using our current compression, but the trade-offs are that compression takes 62% longer and webp may not be broadly compatible yet. We’ll keep looking into it.

Note that if we do change our image compression and resizing specs, we wouldn’t run existing images through that - just newly uploaded ones.