Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Depixelizing Pixel Art

research.microsoft.com

Post reply on HN
Print view View original

41–50 of 164 posts

Re: Depixelizing Pixel Art

#41

Post by lloeki »

zeidrich wrote: post #35

This is a pretty old paper, but I hadn't seen the live demo. That's pretty cool. A problem with this algorithm is that it's pretty slow. It would be hard to use it for real time scaling. I think that it's pretty cool though for any precalculated conversion to vector format. It would also be pretty cool if there were software that allowed you to create a pixel art image with a live preview in this format and the abili…

> If you had a program that let you author your sprites under the same conditions, but let you preview an upscaled version

Combine Atwood's law with a proposed law of mentioning ideas on HN being implemented shortly thereafter and there may be a HTML5+JS implementation popping up as a "Show HN" soon.

Re: Depixelizing Pixel Art

#42

Post by ahassan »

bri3d wrote: post #29
rkuykendall-com wrote: post #24

Earlier quoted context omitted.

Do you know if MS is working on Mac-Style resolution independence for W9? I'm currently running a Retina MBP, at 2x res I think, and it works _perfectly_. The first few months some apps didn't work well, but the community adapted very quickly.

Windows has had support for resolution independence where DPI is configurable across a continuum (rather than only available as 1x or 2x scale like on the Mac) for quite some time - the issue is that with a huge legacy application base, a giant morass of drawing technologies, and no shipped "HiDPI" or "Retina" Windows hardware until recently, there's been no real incentive for app developers to support it. In Windows…

@DougBTX: Technically, there are 2 scaling levels. There's 1x for normal screens and 2x for retina. If you want one of the intermediate resolutions, it will actually render at 2x, then scale down.

Re: Depixelizing Pixel Art

#43

Post by jjcm »

jrockway wrote: post #14

I wish they would use this in Windows 8. As far as I can tell, their scaling algorithm for 4k displays is: scale up 2x using nearest neighbor, then randomly drop pixels to get back to 125% or 150%. The result is horrifyingly bad. Not just kind of bad, but unusably bad. (Adding insult to injury, they ClearType the text before scaling.)

While something similar would probably be better, this is heavily optimized for pixel artwork. Lots of curves, shading, and most importantly - limited colors. UI is generally much straighter, less shaded, with far more colors.

Here's an example of UI that's scaled with potrace (a similar algorithm): http://i.imgur.com/jDq4M7e.png (left side is the converted side, right side is nearest-neighbor. Top is 3x, bottom is 2x)

That's with the highest amount of colors/depth that potrace allows. On an i7 processor, it takes a LONG time to compute all of that. Each icon is no longer just a couple hundred pixels, it's a couple hundred vector paths. Even rendering it takes a number of seconds to refresh the screen in inkscape.

Re: Depixelizing Pixel Art

#46

Post by jrockway »

bluedino wrote: post #20
jrockway wrote: post #14

I wish they would use this in Windows 8. As far as I can tell, their scaling algorithm for 4k displays is: scale up 2x using nearest neighbor, then randomly drop pixels to get back to 125% or 150%. The result is horrifyingly bad. Not just kind of bad, but unusably bad. (Adding insult to injury, they ClearType the text before scaling.)

I would guess it's for performance reasons.

I have 4 i7 cores and a $500 graphics card. I feel like it's possible :)

TF2, for example, plays beautifully at 3840x2160@60Hz. Scaling up the graphics for an 800x600 visual novel that plays at 1 frame per 30 seconds is computationally possible.

(The good news is that someone has written an emulator for one VN that I'm working through, so I should be able to play with scaling in that way. If I can get it to compile.)

Re: Depixelizing Pixel Art

#47

Post by glhaynes »

zeidrich wrote: post #35

This is a pretty old paper, but I hadn't seen the live demo. That's pretty cool. A problem with this algorithm is that it's pretty slow. It would be hard to use it for real time scaling. I think that it's pretty cool though for any precalculated conversion to vector format. It would also be pretty cool if there were software that allowed you to create a pixel art image with a live preview in this format and the abili…

A problem with this algorithm is that it's pretty slow. It would be hard to use it for real time scaling.

Even if it's too slow for realtime on today's hardware, I'd love to see some prerendered sample videos.

Re: Depixelizing Pixel Art

#48

Post by Lerc »

sp332 wrote: post #16

I wonder why they all fall down on Peach and Peach 2? None of them look nearly as good (to me) as bicubic.

I think it comes down to your point of focus. With peach and peach 2, The eyes change shape quite a bit. Humans notice that much more than other aspects.

In general, I think the "ours" method could benefit by moving the boundaries between colours in and out until they get an average brightness match with the similar area in the nearest neighbour version. A lot of the "ours" images have a higher proportion of black.

Post reply on HN