Wen Sijia, Zheng Yinqiang, Lu Feng
IEEE Trans Image Process. 2021;30:7280-7291. doi: 10.1109/TIP.2021.3104188. Epub 2021 Aug 20.
Since specular reflection often exists in the real captured images and causes deviation between the recorded color and intrinsic color, specular reflection separation can bring advantages to multiple applications that require consistent object surface appearance. However, due to the color of an object is significantly influenced by the color of the illumination, the existing researches still suffer from the near-duplicate challenge, that is, the separation becomes unstable when the illumination color is close to the surface color. In this paper, we derive a polarization guided model to incorporate the polarization information into a designed iteration optimization separation strategy to separate the specular reflection. Based on the analysis of polarization, we propose a polarization guided model to generate a polarization chromaticity image, which is able to reveal the geometrical profile of the input image in complex scenarios, e.g., diversity of illumination. The polarization chromaticity image can accurately cluster the pixels with similar diffuse color. We further use the specular separation of all these clusters as an implicit prior to ensure that the diffuse component will not be mistakenly separated as the specular component. With the polarization guided model, we reformulate the specular reflection separation into a unified optimization function which can be solved by the ADMM strategy. The specular reflection will be detected and separated jointly by RGB and polarimetric information. Both qualitative and quantitative experimental results have shown that our method can faithfully separate the specular reflection, especially in some challenging scenarios.
由于在实际采集的图像中常常存在镜面反射,导致记录的颜色与物体固有颜色之间产生偏差,镜面反射分离对于多个需要一致物体表面外观的应用具有优势。然而,由于物体的颜色受光照颜色的显著影响,现有研究仍然面临近乎重复的挑战,即当光照颜色接近表面颜色时,分离变得不稳定。在本文中,我们推导了一个偏振引导模型,将偏振信息纳入设计的迭代优化分离策略中以分离镜面反射。基于对偏振的分析,我们提出一个偏振引导模型来生成偏振色度图像,该图像能够揭示复杂场景(例如光照多样性)下输入图像的几何轮廓。偏振色度图像可以准确地对具有相似漫反射颜色的像素进行聚类。我们进一步将所有这些聚类的镜面反射分离结果用作隐式先验,以确保漫反射分量不会被误分离为镜面反射分量。借助偏振引导模型,我们将镜面反射分离重新表述为一个统一的优化函数,该函数可以通过交替方向乘子法(ADMM)策略求解。镜面反射将通过RGB和偏振信息联合检测和分离。定性和定量实验结果均表明,我们的方法能够如实地分离镜面反射,尤其是在一些具有挑战性的场景中。