I agree with Yushin for practical reasons specific to testing. The various objective metrics all have somewhat tentative relationships to actual human perception, and can only be used with awareness of their limitations. The primary limitation being the fact that different classes of artifacts are not penalized consistently, and so the metrics cannot be used as a black box to compare the relative worthiness of completely different techniques or codecs.
Although multiscale encoding is undeniably useful, it further complicates testing by technique into the mix that the objective metrics are known to fail particularly badly at grading. They handle blurring only slightly better than they handle color*. We may need to account for that and come up with a way to grade it anyway. But it will be work, and there's a good case to be made against designing or modifying our own metrics. It's a task empirically demonstrable to be harder than building the codec itself. Monty (*which is to say, they don't take chroma into account at all) _______________________________________________ video-codec mailing list [email protected] https://www.ietf.org/mailman/listinfo/video-codec
