Automatic Colorization of Freehand Line Drawings Based on Reference Color Images

2015 Fiscal Year Final Research Report

• Project/Area Number: 25330317
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Kansei informatics
• Research Institution: Utsunomiya University
• Principal Investigator: Shoji Kenji 宇都宮大学, 工学(系)研究科(研究院), 教授 (70143188)
• Co-Investigator(Kenkyū-buntansha): MORI HIROSHI 宇都宮大学, 大学院工学研究科, 助教 (80538447)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 手描き線画 / 自動彩色 / ドロネー三角形分割 / 平滑化

Outline of Final Research Achievements

For a freehand line image drawn on a PC screen where a user-selected reference image, e.g., a color photograph, as a guide is faintly displayed with low contrast, we proposed a method for automatic coloring with a constrained Delaunay triangulation that divides the image into small triangles. Using a prototype system based on the proposed method, users can complete impressive pictures by only drawing lines. Our coloring method begins with the triangulation for the set of sampling points on the drawn lines, followed by sampling of color in each triangle on the reference image, smoothing of color among neighboring triangles conditionally, and painting of each triangle with the smoothed color.

Free Research Field

画像処理