结构可知的非局部图像彩色化优化框架
Structure-Aware Nonlocal Optimization Framework for Image Colorization
-
摘要: 以用户的稀疏线条涂画作为交互输入,提出了一个基于非局部能量最优化的结构可知的交互式图像彩色化方法.该方法不仅能够把用户所涂画的颜色扩散到亮度连续的邻近区域,还能扩散到不相邻的纹理相似区域,而无需借助显式的图像分割技术.非局部性颜色扩散原则通过查找每个像素在其高维特征空间中距离最近的K个像素实现.该特征空间不仅包括图像像素的二维空间坐标和亮度值,还包括基于方向对齐的Gabor滤波器所得到的纹理特征值.运用结构图缩放纹理特征值以避免在高对比度边界区域出现的颜色睱疵.多组实验结果和对比演示了本文方法在图像彩色化、选择性重彩色化和去彩色化、渐进式图像颜色编辑等方面的有效性.Abstract: This paper proposes a structure-aware nonlocal energy optimization framework for interactive image colorization with sparse scribbles. Our colorization technique propagates colors to both local intensity-continuous regions and remote texture-similar regions without explicit image segmentation. We implement the nonlocal principle by computing K nearest neighbors in the high-dimensional feature space. The feature space contains not only image coordinates and intensities but also statistical texture features obtained with the direction-aligned Gabor wavelet filter. Structure maps are utilized to scale texture features to avoid artifacts along high-contrast boundaries. We show various experimental results and comparisons on image colorization, selective recoloring and decoloring, and progressive color editing to demonstrate the effectiveness of the proposed approach.