Active Computational Imaging Using a Dense Array of Projectors and Cameras

尽管照相机阵列以各种形式存在了一个多世纪，但投影仪阵列受现有技术的限制，只能使用少量设备。随着可以组装成阵列的投影机数量的增加，人们可以开始将阵列产生的照明视为光场-辐射作为射线在自由空间中的位置和方向的函数。许多研究者对光场进行了抽象的研究；然而，产生光场的物理系统在分辨率上受到投影仪的成本和尺寸的严重限制。研究人员正在建造一个由128个微型、vga分辨率的视频投影仪组成的阵列，并将这些投影仪与现有的128个摄像机阵列交织在一起，从而生产出一种既能记录又能产生光场的设备——这是一种全新的能力。这些新技术将产生基于图像的建模、检查和动作捕捉的新方法，并将在娱乐、考古、训练和任务排练的建模和模拟等领域得到应用。利用现有的相机阵列，研究人员研究了几种类型的高性能成像，包括高速摄像、合成光圈摄影和平铺全景成像。使用新的混合阵列，他们将探索两个额外的问题：(1)同时从每个方向测量物体的3D形状，这意味着平行捕获物体的所有侧面。目前还没有技术可以做到这一点，至少在光学波长上不行。目标是运动物体的近瞬时形状捕获和运动物体的全形状运动捕获。(2)对物理物体进行非逼真的照明，以增强人类观察者所看到的外观。例子包括重新上色、遮蔽或光照，这些都是垂直于物体表面的。

Although arrays of cameras have existed in various forms for more than a century, arrays of projectors have been limited by available technology to small numbers of devices. As the number of projectors that can be feasibly assembled into an array increases, one can begin to treat the illumination produced by the array as a light field - radiance as a function of ray position and direction in free space. The light field has been studied abstractly by numerous researchers; however, physical systems for generating light fields have been severely limited in resolution by the cost and size of projectors. The investigators are building an array of 128 miniature, SVGA-resolution video projectors, and will interleave these projectors with an existing array of 128 video cameras, thereby producing a device that can both record and generate light fields - a fundamentally new capability. These new techniques will yield new methodologies for image-based modeling, inspection and motion capture and will have applications in areas such as in entertainment, archaeology, and modeling and simulation for training and mission rehearsal.Using the existing camera array the investigators have studied several types of high-performance imaging, including high-speed videography, synthetic aperture photography, and tiled panoramic imaging. Using the new hybrid array,they will explore two additional problems: (1) Measuring the 3D shape of an object from every direction at once, meaning capturing all sides of the object in parallel. No existing technology can do this, at least not at optical wavelengths. The goals are near-instantaneous shape capture of a moving object and full-shape motion capture of moving objects. (2) Illumination of physical objects non-photorealistically, to enhance their appearance as seen by a human observer. Examples include recoloring, cloaking, or illumination that is everywhere-perpendicular or everywhere-grazing to the surface of the object.