Johannes Kopf

The authors of this paper also have other amazing image processing/optimization algorithms. Eg: Deblurring, Optimizing Color Consistency, Content-aware Automatic Photo Enhancement, Object Discovery and Segmentation in Internet Images and more: Dani Lischinski's page: http://www.cs.huji.ac.il/~danix/ Johannes Kopf page: http://johanneskopf.de/

This site has a great page that compares various algorithms: http://johanneskopf.de/publications/pixelart/supplementary/multi_compa… While none of them really produce usable results, I love the artistic quality of the Vector Magic algorithm.

Bizarrely, the pixelated stuff in the images you linked look way better. You couldn't use the depixelized whale or dolphin or whatever (our link) in a game, it looks awful. Some of the full comparison is even worse: http://johanneskopf.de/publications/pixelart/supplementary/multi_compa… Mario looks horrid. But you can use literally any of the pixel art'ed images from your link - they all look truly fantastic and production-ready! They're ready to ship now.

This is actually not that great when it comes to Texture Synthesis. This stuff seems better: https://www.think-cell.com/en/pdf/think-cell_article_siggraph2003.pdf https://graphics.stanford.edu/papers/texture-synthesis-sig00/texture.p… http://johanneskopf.de/publications/solid/

It reminds me of a technique for using recursive self-similar tiles to generate pseudorandomly distributed points: http://johanneskopf.de/publications/blue_noise/ The idea is that you can model an infinite set of points generated by an infinitely-deeply-nested tiling, and then efficiently sample from it at arbitrary levels of detail. This lets you do things like zoom in and out while retaining frame-to-frame coherence, and without having to explicitly store the entire point set. (It's worth watching the full 5-minute video, which explains it better than I can.) The implementation in that paper used squares with labeled edges to tile the plane non-periodically. This seems like it could be used to do something similar, except with a periodic but irregular tiling. No idea if that would have any practical benefits, but it's interesting, at least.

See also: https://www.scale2x.it/ https://johanneskopf.de/publications/pixelart/

Had to think of the paper about depixelizing pixel art, fun stuff if you're interested: https://johanneskopf.de/publications/pixelart/paper/pixel.pdf

This one? http://johanneskopf.de/publications/pixelart/index.html It might be apropriate in some cases at least.

Here's the patent http://pdfaiw.uspto.gov/.aiw?docid=20180158227 Here's the prior art from a SIGGRAPH (2011) paper https://johanneskopf.de/publications/pixelart/ What am I missing here?

They compare it to hq4x in their supplementary materials. Theirs is better. http://johanneskopf.de/publications/pixelart/supplementary/index.html

Video is quite neat. http://johanneskopf.de/publications/pixelart/supplementary/video_ours_… Reminds me of some old newgrounds flash animations and games

This page is where all the fun is. But it's also very slow. http://johanneskopf.de/publications/pixelart/supplementary/multi_compa…

when it works it's beautiful but worse cases like mario face are ruined. hq4x isn't as pretty but seems more consistent over the whole gallery of examples http://johanneskopf.de/publications/pixelart/supplementary/multi_compa…

hq4x looks a lot better in the video comparison: http://johanneskopf.de/publications/pixelart/supplementary/video_multi… This method still wins out though.. but interesting never the less.

In their comparison http://johanneskopf.de/publications/pixelart/supplementary/multi_compa… the Vector Magic results appeal the most to me precisely for this reason. For most images they look more like an artists rendition than an attempt to trace the image. Which is good.

The authore of the depixelising algorithm actually also did something like that: "Content-Adaptive Image Downscaling" http://johanneskopf.de/publications/downscaling/ I always thought it was sad that it didn't get as much attention. I think it could also interesting to use in thumbnail generation based on regular photos, for example. Going to ask in that reddit thread if the author is already aware of this algorithm. Might be able to take some cool new ideas from it if they don't! :)

Depixelizing Pixel Art http://johanneskopf.de/publications/pixelart/paper/pixel.pdf I think this paper is very cute and also technically interesting.

Another interesting way of dithering would be http://johanneskopf.de/publications/blue_noise/ but that might take away from the sought aesthetics.

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

It seems like the scribd-mirror has been removed. The original was posted here, but the server is not responding: http://johanneskopf.de/publications/pixelart/paper/pixel.pdf mirrored at http://dl.dropbox.com/u/49901/mirror/pixel.pdf

Source: http://johanneskopf.de/publications/pixelart/index.html submitted as http://news.ycombinator.com/item?id=2578706

Johannes Kopf, the main author behind the original Hyperlapse paper, is one of the researchers behind Localrf discussed here yesterday [0]. I think Hyperlapse Pro [1], which stitched patches from multiple frames together to create new frames after doing some 3D reconstruction and then recreating a smoother camera path was mostly replaced with Hyperlapse mobile [2]. The Pro version was really slow, but the mobile version, which used the original frames from the video, could run in a reasonable time on a phone with almost as good result. Hyperlapse Pro is still available to download [3], Hyperlapse mobile you have to find the APK elsewhere [4]. [0] https://news.ycombinator.com/item?id=36348483 [1] http://johanneskopf.de/publications/hyperlapse/first_person_hyperlapse… [2] https://www.microsoft.com/en-us/research/wp-content/uploads/2016/12/hy… [3] https://www.microsoft.com/en-us/download/details.aspx?id=52379 [4] https://www.apkmirror.com/apk/microsoft-corporation/hyperlapse-mobile/…