[M4IF Technotes] Chroma components in inter4v mode

[Christoph Lampert]

> hi,
> 
> not really completely connected to ME/MC/4MV or MPEG-4,
> but shows how much is the (less) importance of chroma over luma.
> 
> just download this JPEG-2000 related publication.
> 
> http://jj2000.epfl.ch/jj_publications/papers/011.pdf
> 
> see the slides 30-39.

Interesting paper, thank you for the link.
But in YUV 4:2:0 chroma is 1/3 of total uncompressed data, lumi
is 2/3. 
If vectors are chosen such that lumi is compressed better, 
but chroma isn't (maybe even worse), I can't estimate which ration 
of the resulting compressed data chroma is. I'd guess it's more 
than 1/3, because vectors are chosen to minize bits for lumi, not
for chroma. 
I'm not worried about image quality getting worse, because 
it's true that chroma quality is much less important that lumi.
But I'm worried that at a given quantizer the bitstream gets larger 
than necessary, because chroma is motion compensated using a vector that
was never checked to be a good choice for anything. 
Christoph 
-- 
Christoph H. Lampert chl   math.uni-bonn.de | Diese Signature wurde maschi-     
Beringstr. 6, Raum 14 Tel. (0228) 73-2948 | nell erstellt und bedarf
Sprechstunden: keine, aber meistens da    | keiner Unterschrift. AZ 27B-6