[Shacs] Amazing graphics technology

[Dathan Bennett]

A lot of graphical (both 2D and 3D) applications have been developed on 
this class of problems.  Essentially, you define an "energy function" on 
the image (or mesh, for 3D graphics), and then you find a set of pixels 
that define either a global, or more commonly a local minimum or maximum 
of that energy function.  Then you do something with those pixels.  In 
this application, the energy function is basically just the gradient of 
the hypothetical image function, and the minimum of the energy function 
is found by tracing a line across the screen, where from each pixel the 
next pixel in the set is picked from the three-neighborhood of the last 
pixel in the direction of travel (perpendicular to the direction of 
expansion or contraction of the image).

There's nothing really special about the algorithm, aside from the 
ridiculously cool results it gives.  It's very much the same as a host 
of other algorithms in the same domain (you can look at SIGGRAPH for a 
gazillion examples).  The hardest part is coming up with the metric in 
the first place, and then balancing searching efficiency with overall 
performance.  In general, it's computationally infeasible to find the 
set that represents a global minimization of the error metric, so some 
sort of triage is used to decide when and where to search for members of 
the set.  It's a novel idea, but I imagine the implementation is pretty 
mundane.  You just have to have a Ph.D. in math to come up with an 
appropriate error metric in the first place.  (c;


Bronius Motekaitis wrote:
> My coworker and I were talking about that a couple days ago-- indeed 
> it's a smart application of things that already exist.. It has to do 
> with edge detection and sensing general "unimportantness" of an 
> image.  In the video, they use the terms "more energy" and "less 
> energy" referring to more or less sharper edges or contrasts in a 
> given area.  Really smart stuff, and yeah, it will likely be in 
> photoshop.  It will probably make its way as a plugin first-- anyone 
> can write and contribute those....
>
>
> On 8/30/07, *Jonathan Hill* <jonathan.f.hill at gmail.com 
> <mailto:jonathan.f.hill at gmail.com>> wrote:
>
>     This is some of the most amazing computer technology I've ever seen:
>      
>     http://go2web2.blogspot.com/2007/08/fascinating-content-aware-image.html
>     <http://go2web2.blogspot.com/2007/08/fascinating-content-aware-image.html>
>
>     I'm sure the current crop of PUGgers will salivate over this
>     video. :-)
>     According to rumor, Dr. Ariel Shamir has been hired by Adobe to
>     include this in
>     their next version of photoshop. Dr. B may be finally forced to
>     retire! *kidding*
>
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