I'm trying to annotate images. They're only around 6MB, but the interface gets pretty laggy, especially on weaker CPUs. A firefox profile reveals that the entire canvas is re-drawn upon each mouse move, which leads to janky behavior. Here's a link to the profile: https://share.firefox.dev/2OVkInV
Is there a way to fix this? I have already optimised the images to be as small as possible. They cannot become any smaller since they contain text that must remain legible.
Wow, thanks for this next-level reporting, this is super helpful! 
Prodigy definitely shouldn't be redrawing the 6MB image on every move, just the boxes – so that's something we need to fix. I'll look into this. Working with canvas elements can sometimes introduce these subtle performance gotchas.
Workaround in the meantime: You can try setting "image_manual_legacy": true in your config to use the old, SVG-based interface. This will be a lot more efficient, but it only supports a limited set of actions (no freehand shapes, no moving/resizing). But if you're mostly looking to draw some boxes, it should work fine.
Thanks a lot, Ines! We'll try the SVG-based interface. It'll probably work well enough for now 
We have one more question. In the SVG-based interface, how do we "finalise" polygon shapes? We can't seem to figure that out on our own.
Edit: Nevermind, we did figure it out. A double-click will close the current polygon shape.