Calligraphic guideline generation via contour-guided brush fitting

Guidelines play an important role in calligraphy study since they allow beginners to get an idea of how the calligraphic strokes are formed and how to write a calligraphic stroke. However, manually generating guidelines for calligraphic characters is tedious, so only limited calligraphic books with guidelines provided are available. To automatically generate the guidelines, one needs to first decompose the strokes from the character and then automatically generate guideline for each stroke. However, this is very challenging since the existing guideline generation methods only mimic the shapes of the guidelines but generally cannot produce precise guidelines that can be practically used for amateurs to trace the calligraphic strokes. In this paper, we first adopt a state-of-the-artstroke segmentation method based on the information of stroke categories. Then we propose a novel guideline generation method by fitting ellipse-shaped brushes to each stroke based on contour tangents. Extensive visual and quantitative experiments have been conducted to validate the effectiveness of our method. Results and statistics show that our method outperforms existing methods both visually and quantitatively.