Okay, definitely depends on resolutions, specifically the ratio of original to final size.
For example, I created a white-filled 1600x1600 RGB image and tried scaling to a few different sizes:
1/4: 1600x1600 => 400x400 Okay 1/5: 1600x1600 => 320x320 Artifacts 1/8: 1600x1600 => 200x200 Okay
In my original image I was scaling each side to approximately 1/4.7 the size. So it seems that it's at least around this ratio that the bug appears.
Okay, definitely depends on resolutions, specifically the ratio of original to final size.
For example, I created a white-filled 1600x1600 RGB image and tried scaling to a few different sizes:
1/4: 1600x1600 => 400x400 Okay
1/5: 1600x1600 => 320x320 Artifacts
1/8: 1600x1600 => 200x200 Okay
In my original image I was scaling each side to approximately 1/4.7 the size. So it seems that it's at least around this ratio that the bug appears.