A Stained Glass Image Filter David Mould University of Saskatchewan

Stained Glass Filter Goal: transform any image into stained- glass image ?

Stained Glass Cartoon – planned tile layout Leading emphasizes image edges Tiles have simple shapes Few colors used

Voronoi regions Mosaics; Photoshop filter

Stained Glass Tiles Tile boundaries match image edges No large tiles No small tiles No weird tiles

Stained Glass Tiles (2) Tiles should be approximately convex – no bottlenecks No island tiles

Segmentation

ErosionDilation Morphological Operators

Region Smoothing

Tile Repair Bottlenecks detected by progressive erosion. Disconnected components are relabeled and simultaneously dilated into the parent region. Similar approach used to subdivide big tiles.

Completed Cartoon

Bottlenecks split Large regions split

Backgrounds

Backgrounds

Choosing Colors Medieval palette highly restricted Want colors near the image colors, but – bright high contrast from limited palette

Heraldic Tinctures Medieval colorset Corresponds closely to colors available in glass Designed to be vivid and high-contrast

Heraldic Tinctures

Stained Glass Filter Segmentation Region smoothing Removal of small tiles Subdivision of strange-shaped tiles Subdivision of large tiles Tile coloring Rendering

Color Selection Choose heraldic color nearest the original color Map sable to off-white (clear glass)

Rendered Images

Future Work painting glass glass defects – scarring, chipping – as additional channel to match initial image later technology: flashing, etching

Questions?