Geometric Smoothing of Pixel Arts on Basis of Saliency of Colors

Abstract

We present a simple technique for upscaling small pixel-arts. First, an input image is upscaled on the basis of the saliency, i.e., the local majority of each color. The corner of blocks is rounded and jaggy noise on color boundaries is smoothed. Using our method preserves every color in the original image, i.e., smoothes images only geometrically. The upscaling procedure is reversible, i.e., the original pixel-art is easily obtained from the upscaled output. We show with experiments that our method does not produce the unnatural patterns that appear when using the EPX method and the smoothness of edges is also superior.