Pixel Art with Interpolation

Pixel art is a digital art form, that's about creating images out of visible pixels. A lot of the appeal comes from old video games that had small color spaces and low resolutions. The "Bottom Up" approach to pixel art is defining a color space and drawing an image pixel by pixel. We recently learned about an intriguing "Top Down" approach where you start with an image or photograph with a good resolution and create pixel art by repeatedly reducing the resolution using interpolation. Here are a few examples:

The first step is to choose a high resolution image that you want to turn into pixel art. To get a retro video gamey look you may want to start by selecting a small  set of colors and change your image such that it only contains colors of your set. You may even choose an "actual "color set, like e.g. all colors the commodore64 was able to show.

Once your color set is choosen you want to reduce the resolution. A good interpolation method to do that is the nearest-neighbor method. When combining several pixels into one, instead of computing a new value in a weighted sum, the nearest-neighbor method simply picks the value that is the most common among the old pixels. Another trick is to reduce the resolution not at once but in several steps. That way you get several versions of your pixel art and you can choose which one you like best. Here are a few castles with different resolutions along side their originals:

We were also recommended a great software that can perform most of the steps necessary to create such pixel images. Aseprite is not just an image editor, it can also be used to animate frames and is aimed at creating video game sprites and characters. We used aseprite to pixelate both photographs as well as drawn/comic images: