[XviD-devel] Idea for encoding iframes (or images for that matter)

[Jan Lucas]

Christoph Lampert wrote:
> If you are more interested in your own ideas, not connected to MPEG, maybe 
> xvid-devel isn't the right place for a discussion, but rather the 
> comp.compression newsgroup.

Ack.


>>My idea is that a greyscale block could be also seen as a 3D plane in
>>space. The average value would be the center of mass of the finite
>>plane. However, we can define a perpendicular vector coming from that
>>center, and so we can rotate the plane in 3D to approximate our image.
>>
>>A simple gradient could be stored with just 2 vectors. 
>>
>>Now,
>>Split the square in quadrants, and re-calculate the center of mass and
>>rotation for each, storind their difference to the quadtree.  
>>
>>Repeat the recursion until you get to pixel resolution. 

Here is the problem. A slight modification of your idea could be useful
for coding stuff like anime with large areas sharing the same gradient.
But you would need to stop the recursion before you get to pixel
resolution in these areas. That way you would be able to describe a
large area with just a single gradient vector.

>>Well, at least I know that it "looks" faster than applying DCT, or full
>>wavelets. What do you think?

Faster yeah, but also not nearly as good as DCT.


BTW: What do you people think about adding extensions to XVID that
aren't in MPEG-4?

Adding the H.264 4x4 transform to XVID or FLT, a modified DCT described
in this paper <http://citeseer.ist.psu.edu/dequeiroz00fast.html> could
be interresting. (The FLT is a modified DCT transform, with almost
wavelet like behavior, but without the performance hit)

						Jan