The upscaler ran for every enlargement, including the ones a plain resample
wins: measured on a 2048px source cropped and blown back up it loses to
lanczos on PSNR and SSIM at 2x and 3x, and its smoothness reads as plastic
skin and lost texture next to it. From 4x — the model's own factor — it
stops losing, so the threshold moves to 4 and the crop no longer drags a
2x export through it.
The resamples it now carries never set imageSmoothingQuality, and the
default 'low' point-samples: a 1px stripe comes out at full amplitude
instead of the average of what it crossed. Both callers ask for 'high'.
Probe on a 2400x1800 source exported at 4K: 299.9s -> 7.8s, correlation
with the source's 1px/2px bands 0.89/0.95 -> 0.98/0.98, grain sd 25.4 ->
47.1 (a plain HQ resize of the same source keeps 16.1).
3dtours
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