5 ms·

Depixelizing Pixel Art

74 points by jhack 15y ago

burgerbrain 15y ago
Anybody happen to have a mirror of the PDF?
- acqq 15y ago
  I've found only Google cache: http://webcache.googleusercontent.com/search?q=cache:15iKIgSAkDwJ:johanneskopf.de/publications/pixelart/paper/pixel.pdf+http://johanneskopf.de/publications/pixelart/paper/pixel.pdf&cd=1&hl=en&ct=clnk&source=www.google.com http://webcache.googleusercontent.com/search?q=cache:15iKIgS...
  - wlievens 15y ago
    Unfortunately it lacks images, which is critical in this case :-/
- wlievens 15y ago
  I managed to download it. Where could I mirror it? If I give out my dropbox public link, will I get lynched?
  - anateus 15y ago
    Try http://www.scribd.com/ http://www.scribd.com/
  - deleted 15y ago
    [deleted]
- ansgri 15y ago
  It does download successfully if you wait long enough (~5 min).
- AnthonBerg 15y ago
  http://www.scribd.com/doc/56137278/Depixelizing-Pixel-Art http://www.scribd.com/doc/56137278/Depixelizing-Pixel-Art
  - ColinWright 15y ago
    If you put it on Scribd don't you have to declare that you have the right to do that? Don't you have to declare that you are the copyright holder, or that the work is free to copy?
jng 15y ago
Awesome stuff. This is the link to the PDF: http://johanneskopf.de/publications/pixelart/paper/pixel.pdf It takes a while to start, but I just downloaded it now...
ansgri 15y ago
BTW, there's a video of some Mario game upscaled with this algorithm. Looks very modern! http://johanneskopf.de/publications/pixelart/supplementary/video_ours_4x_h264.mp4 http://johanneskopf.de/publications/pixelart/supplementary/v... (3MB)
- sek 15y ago
  alt here: http://ifile.it/gj1tlk5/video_ours_4x_h264.mp4 http://ifile.it/gj1tlk5/video_ours_4x_h264.mp4
  - pezh0re 15y ago
    Alternate alternate mirror here: http://www.filesonic.com/file/1061063604/video_ours_4x_h264.mp4(I http://www.filesonic.com/file/1061063604/video_ours_4x_h264.... had trouble with ifile.it at work)
    - dspillett 15y ago
      "You may have reached this page due to a known problem with some UK ISPs" with absolutely no description of what that known problem that they know about actually is. Very bad UI decision there. I'm pretty sure I can guess what the problem is (the IWF filter, no doubt) but if I were an ISP and got a pile of reports from users simply parrotting that message I'd block the site completely until they improved it. It is like me as a programmer getting "I gots an error message" from a user who then says "oh, I didn't read it all" when I ask what the error message actually was.
mrspeaker 15y ago
I love the image caption regarding anti-aliased cases: A less successful case. Anti-aliased inputs are difficult to handle for our algorithm. “We are doomed...”
hackermom 15y ago
This is actually nothing new. Without meaning to criticize the author's efforts, the whole paper has a strong feel of being "reinventive". There are several algorithms for this in use since long (almost all of which were made specifically to improve video game console emulators) such as the early EPX algo from 1992, and the newer MAME algorithms and hqx. http://en.wikipedia.org/wiki/Pixel_art_scaling_algorithms http://en.wikipedia.org/wiki/Pixel_art_scaling_algorithms
- pygy_ 15y ago
  Actually, it is in a completely different league. The algorithms you linked to output bitmaps. Kopf and Lischinsk's algorithm is a vectorizer, optimized for old school graphics. This means that its outputs is resolution-independent. Similar tools include Potrace[1] (open source, but for black and white images) and Vector Magic[2] (multicolor, but proprietary). However, the use of Voronoï diagrams is AFAIK original, and their results are superior to hqNx at similar resolutions. [1]http://potrace.sourceforge.net/ http://potrace.sourceforge.net/ [2]http://vectormagic.com/home http://vectormagic.com/home
- AnthonBerg 15y ago
  They compare their results to hq4x, and arguably come out ahead. Has the same algorithm been proposed before? (I take it that it hasn't. So it is indeed new ...)
- mykhal 15y ago
  you obviously did not get it..
demonicus 15y ago
Here's the document in image format: http://imgur.com/a/gRXPJ http://imgur.com/a/gRXPJ
ColinWright 15y ago
Further discussion in a duplicate submission a week later: http://news.ycombinator.com/item?id=2601347 http://news.ycombinator.com/item?id=2601347

74 points by jhack 15y ago

burgerbrain 15y ago

Anybody happen to have a mirror of the PDF?

acqq 15y ago
I've found only Google cache: http://webcache.googleusercontent.com/search?q=cache:15iKIgSAkDwJ:johanneskopf.de/publications/pixelart/paper/pixel.pdf+http://johanneskopf.de/publications/pixelart/paper/pixel.pdf&cd=1&hl=en&ct=clnk&source=www.google.com http://webcache.googleusercontent.com/search?q=cache:15iKIgS...
- wlievens 15y ago
  Unfortunately it lacks images, which is critical in this case :-/
wlievens 15y ago
I managed to download it. Where could I mirror it? If I give out my dropbox public link, will I get lynched?
- anateus 15y ago
  Try http://www.scribd.com/ http://www.scribd.com/
- deleted 15y ago
  [deleted]
ansgri 15y ago
It does download successfully if you wait long enough (~5 min).
AnthonBerg 15y ago
http://www.scribd.com/doc/56137278/Depixelizing-Pixel-Art http://www.scribd.com/doc/56137278/Depixelizing-Pixel-Art
- ColinWright 15y ago
  If you put it on Scribd don't you have to declare that you have the right to do that? Don't you have to declare that you are the copyright holder, or that the work is free to copy?

jng 15y ago

Awesome stuff. This is the link to the PDF: http://johanneskopf.de/publications/pixelart/paper/pixel.pdf It takes a while to start, but I just downloaded it now...

ansgri 15y ago

BTW, there's a video of some Mario game upscaled with this algorithm. Looks very modern! http://johanneskopf.de/publications/pixelart/supplementary/video_ours_4x_h264.mp4 http://johanneskopf.de/publications/pixelart/supplementary/v... (3MB)

sek 15y ago
alt here: http://ifile.it/gj1tlk5/video_ours_4x_h264.mp4 http://ifile.it/gj1tlk5/video_ours_4x_h264.mp4
- pezh0re 15y ago
  Alternate alternate mirror here: http://www.filesonic.com/file/1061063604/video_ours_4x_h264.mp4(I http://www.filesonic.com/file/1061063604/video_ours_4x_h264.... had trouble with ifile.it at work)
  - dspillett 15y ago
    "You may have reached this page due to a known problem with some UK ISPs" with absolutely no description of what that known problem that they know about actually is. Very bad UI decision there. I'm pretty sure I can guess what the problem is (the IWF filter, no doubt) but if I were an ISP and got a pile of reports from users simply parrotting that message I'd block the site completely until they improved it. It is like me as a programmer getting "I gots an error message" from a user who then says "oh, I didn't read it all" when I ask what the error message actually was.

mrspeaker 15y ago

I love the image caption regarding anti-aliased cases: A less successful case. Anti-aliased inputs are difficult to handle for our algorithm. “We are doomed...”

hackermom 15y ago

This is actually nothing new. Without meaning to criticize the author's efforts, the whole paper has a strong feel of being "reinventive". There are several algorithms for this in use since long (almost all of which were made specifically to improve video game console emulators) such as the early EPX algo from 1992, and the newer MAME algorithms and hqx. http://en.wikipedia.org/wiki/Pixel_art_scaling_algorithms http://en.wikipedia.org/wiki/Pixel_art_scaling_algorithms

pygy_ 15y ago
Actually, it is in a completely different league. The algorithms you linked to output bitmaps. Kopf and Lischinsk's algorithm is a vectorizer, optimized for old school graphics. This means that its outputs is resolution-independent. Similar tools include Potrace[1] (open source, but for black and white images) and Vector Magic[2] (multicolor, but proprietary). However, the use of Voronoï diagrams is AFAIK original, and their results are superior to hqNx at similar resolutions. [1]http://potrace.sourceforge.net/ http://potrace.sourceforge.net/ [2]http://vectormagic.com/home http://vectormagic.com/home
AnthonBerg 15y ago
They compare their results to hq4x, and arguably come out ahead. Has the same algorithm been proposed before? (I take it that it hasn't. So it is indeed new ...)
mykhal 15y ago
you obviously did not get it..

demonicus 15y ago

Here's the document in image format: http://imgur.com/a/gRXPJ http://imgur.com/a/gRXPJ

ColinWright 15y ago

Further discussion in a duplicate submission a week later: http://news.ycombinator.com/item?id=2601347 http://news.ycombinator.com/item?id=2601347