Automatic Image-Based Pencil Sketch Rendering

This paper presents an automatic image-based approach for convertinggreyscale images to pencil sketches, in which strokes follow the imagefeatures. The algorithm first extracts a dense direction fieldautomatically using Logical/Linear operators which embody the drawingmechanism. Next, a reconstruction approach based on asampling-and-interpolation scheme is introduced to generate stroke pathsfrom the direction field. Finally, pencil strokes are rendered along thespecified paths with consideration of image tone and artificialillumination. As an important application, the technique is applied torender portraits from images with little user interaction. Theexperimental results demonstrate that the approach can automaticallyachieve compelling pencil sketches from reference images.