Abstract: Medieval stained glass windows are a stylized artform that has not previously been thoroughly treated in the computer graphics literature. In this paper, we present an automated method for transforming an arbitrary image into a stained-glass version of that image. The key issues in designing a stained glass window are the tile boundaries and tile colors. We use erosion and dilation operators to manipulate and smooth an initial region segmentation tiling; we choose tile colors from the palette of heraldic tinctures; and finally, we render a displacement-mapped plane to obtain our final image.