Hahne Christopher, Aggoun Amar
IEEE Trans Image Process. 2021;30:6757-6771. doi: 10.1109/TIP.2021.3095671. Epub 2021 Jul 28.
Light-field cameras play a vital role for rich 3D information retrieval in narrow range depth sensing applications. The key obstacle in composing light-fields from exposures taken by a plenoptic camera is to computationally calibrate, align and rearrange four-dimensional image data. Several attempts have been proposed to enhance the overall image quality by tailoring pipelines dedicated to particular plenoptic cameras and improving the consistency across viewpoints at the expense of high computational loads. The framework presented herein advances prior outcomes thanks to its novel micro image scale-space analysis for generic camera calibration independent of the lens specifications and its parallax-invariant, cost-effective viewpoint color equalization from optimal transport theory. Artifacts from the sensor and micro lens grid are compensated in an innovative way to enable superior quality in sub-aperture image extraction, computational refocusing and Scheimpflug rendering with sub-sampling capabilities. Benchmark comparisons using established image metrics suggest that our proposed pipeline outperforms state-of-the-art tool chains in the majority of cases. Results from a Wasserstein distance further show that our color transfer outdoes the existing transport methods. Our algorithms are released under an open-source license, offer cross-platform compatibility with few dependencies and different user interfaces. This makes the reproduction of results and experimentation with plenoptic camera technology convenient for peer researchers, developers, photographers, data scientists and others working in this field.
在窄范围深度传感应用中,光场相机对于丰富的三维信息检索起着至关重要的作用。从全光相机拍摄的曝光图像中合成光场的关键障碍在于对四维图像数据进行计算校准、对齐和重新排列。已经提出了几种尝试,通过定制专门针对特定全光相机的流程并以高计算负载为代价提高视点间的一致性来提高整体图像质量。本文提出的框架取得了比先前更好的成果,这得益于其新颖的微图像尺度空间分析,可实现独立于镜头规格的通用相机校准,以及基于最优传输理论的视差不变、经济高效的视点颜色均衡。以创新方式补偿了来自传感器和微透镜网格的伪像,以在具有子采样能力的子孔径图像提取、计算重聚焦和倾斜校正渲染中实现卓越的质量。使用既定图像指标的基准比较表明,我们提出的流程在大多数情况下优于当前的先进工具链。瓦瑟斯坦距离的结果进一步表明,我们的颜色转移优于现有的传输方法。我们的算法以开源许可发布,具有跨平台兼容性,依赖项少且用户界面多样。这使得同行研究人员、开发人员、摄影师、数据科学家以及该领域的其他工作人员能够方便地重现结果并对全光相机技术进行实验。