图像特征保持的圆点绘制方法

图像圆点绘制问题指用圆点去逼近图像得到近似马赛克填充的效果.点画是在世界范围内流行的艺术形式,图像圆点绘制算法就是受艺术家创作的点画作品启发而提出的一种非真实感渲染算法.首先对图像进行分割,提取分割后图像的轮廓边界线并获取原始图像的特征线,生成图像上的方向场,使得图像的每个像素点位置都存在一个方向值;之后设计密度函数,刻画待摆放的圆点半径大小随着图像梯度的变化;最后结合方向场和密度函数根据一定的规则开始圆点的摆放直至铺满图像区域.此外,后续的补洞优化使得画面更加饱满.采用上述算法在大量图片上进行实验的结果表明,图像圆点绘制算法能够生成与图像特征和颜色相适应的圆点逼近结果,圆点的排列与原图片的特征保持了高度的一致,而且画面整体颜色与原图像十分接近.

A Feature-Aware Method for Dot Painting on Images

Dot painting is a technique of painting which uses small dots of color to form an image.Dot painting is a popular art style,and the dot painting method proposed in this paper is inspired by dot painting artworks created by artists.In our method,we segment an input image and extract the outline of the segmented image firstly and then get the feature outline of the original image.With this two kinds of outline,we generate an orientation field on the image,which ensures that there exists a direction at the location of each pixel to guide the dot placement.Next we design a density function to reflect how the dot size changes as the gradient of the image changes.At last,we put circles in the image region based on the orientation field and the density function mentioned above,and the algorithm ends when the image domain is filled with dots.Besides,we fill holes left to make the results look better.Experimental results show that our circle dot painting method can generate proper results reflecting the features and colors of the input image.The generated dots adhere to the features of the input image and the colors of the dots are very close to the input image colors.