plupload defines MAX_RESIZE_WIDTH and MAX_RESIZE_HEIGHT as 8192 pixels each.

If an image is uploaded that has a resolution exceeding either of these, it passes through without being resized. As far as I can read, this behaviour is by design.

We're starting to see phone cameras that exceed this, sometimes dramatically (as in the case of the Samsung S26)

I'm not sure if plupload is still being maintained, but in our instance of phpBB3 I've modified assets/plupload.full.min.js to increase both values to 16384. Tests show the browser is happy with this. It's a shame that plupload doesn't block the upload entirely, not sure how to go about this.