The algorithm first scales the image to 8 times its original size with a modified Scale2× algorithm which treats similar (rather than identical) pixels as matches. It produces far fewer artifacts than nearest-neighbor rotation algorithms, and like EPX, it does not introduce new colors into the image (unlike most interpolation systems). RotSprite is a scaling and rotation algorithm for sprites developed by Xenowhirl. Here is an example of a sprite in the original size, upscaled by factor 3 without interpolation and then rotated by 30° with linear interpolation:

But that's usually still just a lazy substitute which doesn't reach the quality you can reach with manual work. To avoid your sprites from getting blurred while in original orientation, always ensure that the drawing position is rounded to the nearest integer (some graphic engines/frameworks/libraries allow you to draw sprites on floating-point coordinates which often results in blurring). If you use a faux-retro look where your sprites are actually in a far higher resolution than they look, you can sometimes get away with upscaling them by an integer factor without interpolation in your graphic editor and then rotating them in linear interpolation at runtime. If you want to maintain the pixel-art aesthetics you usually won't get around redrawing your art in each angle. Automatic rotation of pixel art by other angles than 90° usually goes wrong.

Pixel art in krita