A Texture-Based Approach for Hatching Color Photographs

We present a texture-based approach that hatches color photographs. We use a Delaunay triangulation to create a mesh of triangles with sizes that reflect the structure of an input image. At each vertex of this triangulation, the flow of the image is analyzed and a hatching texture is then created with the same alignment, based on real pencil strokes. This texture is given a modified version of a color sampled from the image, and then it is used to fill all the triangles adjoining the vertex. The three hatching textures that accumulate in each triangle are averaged, and the result of this process across all the triangles form the output image. This method can produce visually pleasing hatching similar to that seen in colored-pencil strokes and oil paintings.