[XviD-devel] Global Motion Compensation

[Marco Al]

Christoph Lampert wrote:

>> Least median of squares seems to be the most popular method.
>
> Smolic starts with "structured" blocks only and uses a Maximum-Likelihood
> approach after that. He claims results are very good (and fast).

That might be nicely combined with a MB classifier for adaptive quantization. He
uses a faster (but slightly less-) robust estimator than LMedS.

Since you talked with him ... why does he in the "Real Time ..." paper only use
the robust estimator for finding an estimate for the translation and not the
other parameters of the affine transform? He does do so in his thesis for
finding global motion from the MPEG-2 motion vectors, but he does not refine
them afterwards for some reason ... he must have considered it, estimating all
parameters before gradient descent search, but Id still like to know the reasons
why it was not a good idea :)

Marco