TY - JOUR
T1 - Keypoint-driven line drawing vectorization via PolyVector flow
AU - Puhachov, Ivan
AU - Neveu, William
AU - Chien, Edward
AU - Bessmeltsev, Mikhail
N1 - Publisher Copyright:
© 2021 ACM.
PY - 2021/12/10
Y1 - 2021/12/10
N2 - Line drawing vectorization is a daily task in graphic design, computer animation, and engineering, necessary to convert raster images to a set of curves for editing and geometry processing. Despite recent progress in the area, automatic vectorization tools often produce spurious branches or incorrect connectivity around curve junctions; or smooth out sharp corners. These issues detract from the use of such vectorization tools, both from an aesthetic viewpoint and for feasibility of downstream applications (e.g., automatic coloring or inbetweening). We address these problems by introducing a novel line drawing vectorization algorithm that splits the task into three components: (1) finding keypoints, i.e., curve endpoints, junctions, and sharp corners; (2) extracting drawing topology, i.e., finding connections between keypoints; and (3) computing the geometry of those connections. We compute the optimal geometry of the connecting curves via a novel geometric flow - - PolyVector Flow - - that aligns the curves to the drawing, disambiguating directions around Y-, X-, and T-junctions. We show that our system robustly infers both the geometry and topology of detailed complex drawings. We validate our system both quantitatively and qualitatively, demonstrating that our method visually outperforms previous work.
AB - Line drawing vectorization is a daily task in graphic design, computer animation, and engineering, necessary to convert raster images to a set of curves for editing and geometry processing. Despite recent progress in the area, automatic vectorization tools often produce spurious branches or incorrect connectivity around curve junctions; or smooth out sharp corners. These issues detract from the use of such vectorization tools, both from an aesthetic viewpoint and for feasibility of downstream applications (e.g., automatic coloring or inbetweening). We address these problems by introducing a novel line drawing vectorization algorithm that splits the task into three components: (1) finding keypoints, i.e., curve endpoints, junctions, and sharp corners; (2) extracting drawing topology, i.e., finding connections between keypoints; and (3) computing the geometry of those connections. We compute the optimal geometry of the connecting curves via a novel geometric flow - - PolyVector Flow - - that aligns the curves to the drawing, disambiguating directions around Y-, X-, and T-junctions. We show that our system robustly infers both the geometry and topology of detailed complex drawings. We validate our system both quantitatively and qualitatively, demonstrating that our method visually outperforms previous work.
KW - frame field
KW - geometric flow
KW - line drawing
KW - vectorization
UR - http://www.scopus.com/inward/record.url?scp=85135143435&partnerID=8YFLogxK
U2 - 10.1145/3478513.3480529
DO - 10.1145/3478513.3480529
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AN - SCOPUS:85135143435
SN - 0730-0301
VL - 40
JO - ACM Transactions on Graphics
JF - ACM Transactions on Graphics
IS - 6
M1 - 266
ER -