image_quality is an official no-reference image_static quality metric. It evaluates prediction frames with the MUSIQ-SPAQ image-quality model and does not require a paired reference rollout.
For each protocol-selected prediction frame Ii, MUSIQ produces a native score qi on its [0,100] scale. WorldAtlas normalizes and clips each score,
si=clip(100qi,0,1),
then averages the normalized frame scores:
SMUSIQ=N1i=1∑Nsi.
Higher is better. The resulting value enters per_metric_summary and the equal-weight seven-metric quality total. The default backend is musiq, with longer preprocessing.