I believe Simpleresize has a bug...

[Katie Boundary]

...that causes it to shrink the image slightly, as if negative cropping was being performed before the resize, at least when downscaling.

This is disappointing, as I was fond of using Simpleresize as a computationally cheap but more accurate substitute for Reduceby2.

[poisondeathray]

It looked ok for me on a downscale from 1024x1024 to 512x512 on a quick test

Can you post a demo or sample script to reproduce the issue ?

EDIT: I can see the issue when upscaling 720x480 16:9 to 1920x1080 - compared to a "traditional" resizer, the simpleresize results appear zoomed in more , or lose some border pixels

[Katie Boundary]

That makes sense. My best guess is that the filter treats the centers of the edge pixels, rather than the edges of the edge pixels, as being the edge of the image, so you'd get a zooming-out when downscaling and a zooming-in when upscaling.