A Stained Glass Image Filter

1. A Stained Glass Image Filter David Mould University of Saskatchewan

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

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

6. Voronoi regions • Mosaics; Photoshop filter

7. Stained Glass Tiles • Tile boundaries match image edges • No large tiles • No small tiles • No “weird” tiles

8. Stained Glass Tiles (2) • Tiles should be “approximately convex” – no bottlenecks • No “island” tiles

9. Segmentation

10. Morphological Operators • Erosion • Dilation

11. Region Smoothing

12. Region Smoothing

13. 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.

14. Completed Cartoon

15. Completed Cartoon Large regions split Bottlenecks split

16. Backgrounds

17. Backgrounds

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

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

20. Heraldic Tinctures

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

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

23. Rendered Images

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

30. Questions?