Depixelizing Pixel Art

Two researchers (Johannes Kopf and Dani Lischinski) have created a novel algorithm that turns old 8-bit artwork into impressive upscaled vectors. As you can see from the Super Mario World dolphin below, the results are incredibly good.

Depixelising Pixel Art

“Our algorithm resolves pixel-scale features in the input and converts them into regions with smoothly varying shading that are crisply separated by piecewise-smooth contour curves. In the original image, pixels are represented on a square pixel lattice, where diagonal neighbours are only connected through a single point. This causes thin features to become visually disconnected under magnification by conventional means, and it causes connectedness and separation of diagonal neighbours to be ambiguous. The key to our algorithm is in resolving these ambiguities. This enables us to reshape the pixel cells so that neighbouring pixels belonging to the same feature are connected through edges, thereby preserving the feature connectivity under magnification. We reduce pixel aliasing artifacts and improve smoothness by fitting spline curves to contours in the image and optimizing their control points.” – Johannes Kopf

For a better idea of just how accurate their algorithm is, you should look at the other samples here – http://research.microsoft.com/en-us/um/people/kopf/pixelart/supplementary/multi_comparison.html

So what does this research mean for gamers? First of all, the algorithm isn’t always successful. Some of their other examples display its current shortcomings. The other problem with Depixelizing Pixel Art is that to many fans of retro gaming, there is nothing wrong with pixels. Pixel art is ever growing in popularity, so to many enthusiasts there is no need for smoothing of graphics. From personal experience, I often turn off these modes in re-releases on the Xbox and PlayStation.

Boo - Super Mario Brothers

What is does mean is that researchers are beginning to perfect upscaling techniques and at some point in the future we may be able to have retro games re-visualised in HD vectors, without losing the charm and character of the original graphics. The potential is that the upscaling could be performed in realtime, making it quicker and easier for companies such as Nintendo to re-release classic games without worrying too much about how to display them on modern displays and resolutions.

I love pixel art, but this is certainly very interesting. You can read more about Depixelizing Pixel Art on their website – http://research.microsoft.com/en-us/um/people/kopf/pixelart/

 

Matt has been hooked on games since he received his first console (a SEGA Mega Drive) for his 7th birthday. He now spends most of his time on the Xbox One, Xbox 360 and Nintendo 3DS, but will use any excuse for a retro gaming night.


Posted on April 29, 2014 | Last modified: 29th April 2014