
Depixelizing Pixel Art - wmwong
http://research.microsoft.com/en-us/um/people/kopf/pixelart/index.html
======
imurray
Earlier comments: <http://news.ycombinator.com/item?id=2601347>
<http://news.ycombinator.com/item?id=2578706>

Some of the previous discussion isn't great (squabbling about dupes, not being
able to download the pdf). A common comment was "hasn't this been done
before". Many existing tools output higher-res bitmaps, this tool outputs
vector images. They did run comparisons to a variety of algorithms, including
potrace, which also generates vectors.

~~~
petercooper
When we get stories like this that get repeated multiple times on Hacker News
(a few others spring to mind recently) it's a minor annoyance if you're an
ardent HN reader but a significant indicator of what HN readers _really_ find
interesting on the whole since it's getting voted up each time by a different
subset of users who hadn't seen it before.

Things involving novel presentations of algorithms and well presented 'undry'
academic papers seem to do _very_ well in this regard..

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bane
Even though it does a terrible job staying true to the source material, I'd
bet playing an old game rendered through a vector magic filter would have an
interesting abstract aspect to it.

~~~
eru
In the discussion to one of the previous submissions, somebody posted a
depixelated video of Super Mario World.

~~~
joshzayin
For reference: <http://www.youtube.com/watch?v=o2Fd-4NzB0w>

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JonnieCache
Here's a page where you can compare various algorithms, including this new
one, over many classic pieces of pixel art:

[http://research.microsoft.com/en-
us/um/people/kopf/pixelart/...](http://research.microsoft.com/en-
us/um/people/kopf/pixelart/supplementary/multi_comparison.html)

~~~
tripzilch
Beautiful! I especially love the bits near the end, where they apply it to
oldskool Windows 3.1 icons :D

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CognitiveLens
I like the algorithm, but the hq4x seems to produce better fine shapes such as
eyes and skeleton bones (albeit in bitmap form) - it would be interesting to
see some sort of hybrid algorithm taking the best features of both to produce
a vector output.

~~~
mambodog
I feel like hq4x is probably a better choice for upscaling videogames, as it
feels like it better maintains the original 'intent' of the art, which was,
after all, designed with low-res in mind. The Microsoft algorithm, on the
other hand, seems like it would be really useful for recovering graphics that
have been downsampled algorithmically (as opposed to graphics originally drawn
at low resolutions).

~~~
imurray
Except that the doom example in the paper (figure 11) shows that down-sampled
images aren't recovered well. The posted work is designed for pixel art.

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tomerico
I wonder how difficult is it to generalize the algorithm to 3d voxels, and
apply it on Minecraft.

~~~
Deestan
The Minecraft voxels are decorated by textures that are designed to fit the
cube form. A devoxalization is going to look like crap.

~~~
personalcompute
I think he means disregarding all that and looking at the raw voxels then
applying a modified version of this algorithm, similar to marching cubes.

~~~
Deestan
I know. But when displaying the Minecraft landscape afterwards you either have
to leave the disregarded textures out, which looks like crap, or apply them
stretched, which looks like total crap, or apply a smoothed gradient, which
also looks like crap compared to the original landscape. :-)

Given that he suggested Minecraft terrains, I opined on how Minecraft would
look with such an algorithm applied.

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tejask
This is an interesting paper. Though I only read the abstract, it seems like
real-time performance could be achieved by utilizing GPUs for B-spline
calculations. Would be awesome for video games if real-time performance can be
achieved!

~~~
antifuchs
Needing a high-end gaming machine to run Super Mario World or Space Invader at
acceptable frame rates would be fun, for a change (-:

~~~
liuliu
Can you run the algorithm on graphic resource first to produce vector graphics
and then do the emulator stuff? Seems to me feasible and you can run two
copies of the game (one with vector graphics one without in the background to
ensure the correctness of emulator).

~~~
tejask
If one were to port a game, then before displaying the buffer, one can
generate vector graphics before sending it to the frame buffer. While you can
potentially display both the buffers, I am sure the vectorization phase will
be computationally intensive (thus low fps).

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arturadib
Sorry about the anti-climatic question, but I'm genuinely curious: What's the
main application of this research, other than prettifying old video games?

~~~
pavel_lishin
At a guess, it might make CSI-style "zoom in, enhance" manipulations of images
and videos more plausible.

~~~
nicolasp
This algorithm is specifically designed for pixel art. One of the examples in
the paper shows that it doesn't do very well on anti-aliased graphics.
Therefore it probably wouldn't be of much use on blurry pictures or videos.

------
nicolasp
Previous discussion: <http://news.ycombinator.com/item?id=2601347>

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jhuckestein
Wouldn't this be much harder if the background had more than one color as
well? If that is the case, this new technique may not be applicable to
emulators

~~~
tripzilch
Well, in the paper they do describe some heuristics for separating figure and
ground.

Additionally, a lot of old videogame machines have special built-in routines
to place sprites over a background. So if you'd apply the vectorizing
algorithm separately for the sprite drawing routine--by not just processing
the entire screen after it's rendered, but doing the elements separately--
you'd at least not run into the problem that lines from foreground sprites
meld with background details.

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barefoot
What is the @article block at the bottom of the page?

~~~
vetler
A BibTeX entry: <http://en.wikipedia.org/wiki/BibTeX>

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potomak
great job, I'd like to see it applied on <http://draw.heroku.com> drawings

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bradpineau
Love it.

