Vision Through Rain and Snow

恶劣的天气会严重限制计算机视觉在户外的实用性。算法（分割、跟踪、识别等）在今天的视觉系统中使用的没有装备来处理天气的不利影响。为了使户外视觉系统在所有条件下都能很好地工作，它们必须明确地考虑天气的各种影响。 不同天气条件产生的视觉效果大致可分为两类：稳定（雾、薄雾和霾）和动态（雨、冰雹和雪）。 本研究项目致力于动态天气效应的建模与分析。 研究的第一阶段是开发雨滴和雪花的紧凑和描述性的光度和几何模型。这些模型将用于开发先进的模型forthe动力学和统计特性的雨和雪。 利用这些模型，将开发有效和强大的算法来检测和消除视频中的雨雪。 提出的模型也将用于开发算法，以快速和逼真的渲染雨和雪。此外，开发的模型将被用于设计和实现基于视频摄像机的实时雨雪测量仪。与目前气象科学中使用的仪器相比，这种仪器将非常便宜，但在估计天气参数时将提供高精度。预计拟议研究的结果将对研究和教育产生广泛和切实的影响。从研究的角度来看，这些结果有望影响户外视觉系统的鲁棒性和计算机图形学所能达到的真实感。项目期间开发的模型、算法和数据库将及时广泛传播。在教育方面，PI目前正在开发一门名为“通过大气层的计算机视觉”的课程，这项调查的结果将大大有助于课程的内容。

Bad weather can severely limit the usefulness of computer vision inthe outdoors. The algorithms (segmentation, tracking, recognition,etc.) used in today's vision systems are not equipped to handle theadverse effects of weather. For outdoor vision systems to perform wellin all conditions, they must explicitly account for the diverseeffects of weather. The visual effects produced by different weatherconditions can be broadly classified into two categories: steady (fog,mist and haze) and dynamic (rain, hail and snow). This researchproject is devoted to the modeling and analysis of dynamic weathereffects. The first stage of the study is to develop compact and yetdescriptive photometric and geometric models of raindrops andsnowflakes. These models will be used to develop advanced models forthe dynamical and statistical properties of rain and snow. Usingthese models, efficient and robust algorithms will be developed fordetecting and removing rain and snow from videos. The proposed modelswill also be used to develop algorithms for fast and realisticrendering of rain and snow. In addition, the developed models will beused to design and implement real-time rain and snow gauges based onvideo cameras. Such gauges will be very inexpensive compared to onescurrently used in meteorological sciences, and yet will provide highaccuracy in the estimation of weather parameters.The results of the proposed research are anticipated to have a broadand tangible impact on both research and education. From theperspective of research, the results are expected to impact therobustness of outdoor vision systems and the realism that computergraphics can achieve. The models, algorithms and databases developedduring the project will be broadly disseminated in a timelyfashion. With regards to education, the PI is currently developing acourse titled ``Computer Vision through the Atmosphere,'' and theresults of this investigation will contribute significantly to thecontent of the course.