Depixelizing Pixel Art

像素风格画的矢量化 主讲：钱博磊 2012-01-04

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研究对象

矢量图 -轮廓 轮廓所封闭区域的颜色 像素风格画 图像特征为像素级别

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实现步骤

1. 图像重构 reshape the pixel cells 2. 轮廓提取及拟合 edge detecting and fitting curves 3. 图像绘制 rendering

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图像重构

1.1 重构像素单元格 reshape pixel cell 目标：解决像素图连接模糊性问题，使有 相同颜色与相同特 征 的pixel至少拥有一条共享边

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图像重构

1.1.1 构造相似图 similarity graph

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图像重构

1.1.1 构造相似图 similarity graph curves sparse pixels islands

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图像重构

1.1.2 调整像素单元格 voronoi diagram

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实现步骤

1. 图像重构 reshape the pixel cells 2. 轮廓提取及拟合 edge detecting and fitting curves

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轮廓提取及拟合

2.1 edge detecting and fitting T-junction 问题 • • 连接仅包含vanlence-2结点的可见边 用quadratic B-spline curve拟合 shading edge contour edge

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轮廓提取及拟合

2.3 曲线优化 optimizing the curves 求解: relaxation procedure 局部最优

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轮廓提取及拟合

2.3 防止过优化 corner detection

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图像绘制

3.1 Rendering Truncated Gaussian influence function we place truncated Gaussian influence functions ( = 1, radius 2 pixels) at the cell centroids and set their support to zero outside the region visible from the cell centroid.

The final color at a point is computed as the weighted average of all pixel colors according to their respective influence.

4.1 计算速度 •

结论

4.2 实验结果 •

结论

see the paper