[vorbis-dev] A different take at video encoding - I'm stuck though

[Lourens Veen]

As I said in the other thread (for people using threaded mail)/in my
last mail (for the rest), I'm working on the "split up the frames into
textured triangles and output textures and coordinates" idea. The idea
is to find edges in the image. So far I have a Sobel edge detector, a
wavelet transformer (to compress the textures, still very incomplete,
transform only), and some miscellaneous stuff. The problem is, the Sobel
edge detector gives back a bunch of grey values (quick explanation, I
calc the X and Y differences between pixels, then do edge = sqrt(xd^2 +
yd^2). Dunno if it's Sobel but it looks the same as in Gimp so I suppose
it is). So what I get is a bunch of grey values one pixel smaller in
both directions as the source image.

Problem is, we need vertices and edges. What I want to do is find out
which edge points are adjacent, so a big circle counts as one edge,
which is just a bunch of points. Then triangulate that cloud of points,
using GTS (http://gts.sourceforge.net) for example.

So I find a point in the Sobel edge map that is above a certain
treshold. Each time a new point is to be considered I take the adjacent
pixels of the last pixel, and calculate a score for them. The pixel with
the highest score is taken, and another new one is added, until the
scores drop below a minimum and there's the end of an edge.

Question: How do I calculate the score? I have the direction of the
gradient at the point, the value of the Sobel edge detect, and the
coordinates of the other points in the edge.

Ideas are welcome.

Lourens

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