Automatic Closing of Sketch Boundaries — Opening Doors to Coloring Fun

Coloring a rough sketch gives visualization to our ideas and thoughts. Modern drawing tools that use pen and touch based devices allow for dynamic content creation. Filling colors in a hand drawn sketch requires the sketch boundary to be completely closed, else the fill algorithms leak the color outside the boundary. While sketching may be fun, paying attention to minor gaps requires precision and can be stressful. This paper proposes an efficient algorithm to automatically fill the gaps so as to make the artist focus on the art. The unsupervised learning and clustering technique is applied to identify the disconnected clusters of sketch strokes followed by backtracking algorithm to find the end points to be connected by a closest point search algorithm. Results show an accurate and fast performance for simple sketches.