Show HN: Trigrad, a novel image compression with interesting results

Post by mc808 » Sun, Jul 05, 2015, 3:18 AM UTC

pezzep wrote: post #55

tjradcliffe wrote: post #50

Earlier quoted context omitted.

This is the traditional model of academic publishing that was driven by the limited communication and collaboration ability of the time. A study like the one you describe would be done by multiple co-authors (I don't think I've written an image processing paper that doesn't have at least three people as authors, all of whom actually contributed to the work one way or another.) Furthermore, the traditional paper would…

> What this model of publication does not (yet) have is a reputation mechanism, but it isn't clear it needs one, because you can see the results (and the code) for yourself. As such, I think the author has not only done something interesting in the image compression space, they are pointing the way on the future of scientific publication. The original post is certainly interesting, but that doesn't mean it extends ou…

Post by 1wd » Sun, Jul 05, 2015, 5:12 AM UTC

CyberDildonics wrote: post #57

JoshTriplett wrote: post #29

Very impressive! How might the final rendering look if it used some of the standard triangle shading techniques? Treat the sample points as coordinates in a mesh, assign colors to those coordinates based on what you sampled, then interpolate colors for the points between those coordinates using something like Gouraud or Phong shading (without the lighting). That might produce a satisfying result with fewer samples. I…

Phong is a lighting model. What you are talking about is barycentric interpolation, which is what this is doing. There are already image resizing algorithms that use triangulation (and something called DDE - data dependent interpolation) so the answer to your question is yes it is absolutely a valid idea.

Post by a_e_k » Sun, Jul 05, 2015, 7:47 AM UTC

atinoda-kestrel wrote: post #41

Hmmm... I wonder if there's potential to use this concept for video. Not this implementation, naturally, but the concept. I'm a little too sleep deprived to think through this entirely, but just off the top of my head, it seems like over the course of a few frames that an edge in motion would wind up as a series of triangles where one of the points remains static while the other two shift away from it -- in other wor…

Post by joshu » Tue, Jul 07, 2015, 6:24 AM UTC

1wd wrote: post #17

joshu wrote: post #14

Some more explanation about barycentric coordinate would be appreciated.

Barycentric coordinates are "weights" (u, v, w) that determine a point P on a triangle (A, B, C) by weighting the triangle corner points. You can calculate the cartesian coordinates of P = u * A + v * B + w * C. Since the weights u+v+w = 1 you actually don't need all three: u = 1-v-w, so P = (1-v-w) * A + v * B + w * C = A + v * (B - A) + w * (C - A).

Post by bastijn » Tue, Jul 07, 2015, 10:02 PM UTC

tjradcliffe wrote: post #50

bastijn wrote: post #35

Earlier quoted context omitted.

I mean the author no harm, nor want to talk bad about his work. His work is very cool and I like the amount of information that he gives. Yet, this is far from comparable to academic work. I am inclined to say that you mixed up the sides in your statement, IMHO. Academic work would have explained the benefit of the algorithm. It would have presented it with a side by side comparison with common algorithms and explain…

This is the traditional model of academic publishing that was driven by the limited communication and collaboration ability of the time. A study like the one you describe would be done by multiple co-authors (I don't think I've written an image processing paper that doesn't have at least three people as authors, all of whom actually contributed to the work one way or another.) Furthermore, the traditional paper would…