I'll check it soon
EDIT: cannot reproduce. Tested with AVX2, AVX-only, SSE4.1 only builds. (Win10)
Code:
Function Diff(clip src1, clip src2)
{
return Subtract(src1.ConvertBits(8),src2.ConvertBits(8)).Levels(120, 1, 255-120, 0, 255, coring=false)
}
source=ImageSource("test.png").Info().trim(0, 100) # 256x224 RGB24
c8=source.Spline16Resize(512,384)
c16=source.ConvertTo16Bit().Spline16Resize(512,384).ConvertTo8Bit()
StackVertical(c8,c16,Diff(c8,c16))