Re: the basic idea of my codec

> How exactly would you suggest to integrate motion compensation?

Let's assume we have point with given coordinates screen&time space [x,y,t].
When we want to get the left neighbour, it's coordinates are [x-1,y,t], when
we take the upper neighbour it's [x,y-1,t]. Without motion compensation
taking the previous neighbour in time would be: [x,y,t-1]. With motion
compensation: [x+prevx[x,y], y+prevy[x,y],t-1]. The entries from tables
"prevx" and "prevy" form 2-D vector which means: where this pixel was on the
proevious frame. This approach is exactly the same like in:
http://www.microsoft.com/china/research/dload_files/group/imedia/icme01_MCLI
FT-4th.pdf (pixel adressing - that is).


> AFAICS good motion compensation would decorrelate the sequence to
> the point where 3D coding would not make much sense.

Motion compensation does not decorrelate the signal. Example: you have the
panorama shot with caamer panning form left to right. The motion
compensation would build-up information, that the pixel from frame "t" in
the frame "t+1" moved little to left. You just got more infomation. No
signal change.
...but the wavelet transform , taking into account the motion vectors can be
performed in 3D neighbouhood, thus prediction of pixel value is better than
in 1D case (due to larger neighbourhood. in the simplest case 2 pixels in
1D, 4 in 3D and 6 in 3D).


> The perceptual metric from that paper you mentioned seems a little
> roundabout, since you have greater directional sensitivity in the
transform
> would something directly in the wavelet domain ala Bradley's Wavelet
> Visible Difference Predictor not be more appropriate?

I agree. The predictor I gave was just an example. It is not suitable for
rapid evaluation... The Bradley's seems very fit to the task. I'm
investigating the scheme used in jpeg2000. We'll experiment - we'll see. ;-)


Maciek


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