CIF:Medium:Space-from-Time Imaging: Fundamental Limits, Algorithms, and Preliminary Demonstrations

几个世纪以来，图像的主要技术含义一直是一种视觉表现或对应物，通过光与镜子和透镜的相互作用形成，并通过光化学过程记录下来。在数码摄影中，光化学过程已经被传感器阵列取代，但光学元件的使用没有改变。因此，这种传统成像的空间分辨率受到光学质量和阵列中传感器数量的限制。该项目通过测量光强度的时间变化来响应时间或时空变化的照明，为实现2D和3D的空间分辨率奠定了基础。这是与传统成像的根本背离，在传统成像中，时间只与固定必须收集光线以获得所需对比度的时间段有关。减少对镜头、反射镜和传感器数量的要求既可以降低成本，又可以实现全新的成像配置。尤其令人感兴趣的是在移动设备中实现3D捕获。从时间到空间成像(SFTI)是基于这样的认识，即场景中感兴趣的信息，例如在各种波长和距离成像设备处的双向反射分布函数，被嵌入到从光源到光传感器的传递函数中。此外，光传输是线性的。因此，SFTI引入了新的反问题，其中至少部分正演模型是线性的。研究人员将应用和推广为其他成像方法开发的分析技术，如计算机断层扫描和合成孔径雷达，以发展SFTI的理论基础。分析将受到概念验证实验的启发和启发。

For centuries, the primary technical meaning of image has been a visual representation or counterpart, formed through the interaction of light with mirrors and lenses, and recorded through a photochemical process. In digital photography, the photochemical process has been replaced by a sensor array, but the use of optical elements is unchanged. Thus, the spatial resolution in this traditional imaging is limited by the quality of the optics and the number of sensors in the array. This project develops the foundations of achieving spatial resolution, in 2D and 3D, by measuring temporal variations of light intensity in response to temporally- or spatiotemporally-varying illumination. This is a radical departure from traditional imaging, in which time is associated only with fixing the period over which light must be collected to achieve the desired contrast. Reducing requirements for lenses, mirrors, and numbers of sensors can both lower costs and enable entirely new imaging configurations. Of particular interest is to enable 3D capture in mobile devices such as cell phones.Space-from-time imaging (SFTI) is based on the recognition that information of interest in a scene, such as bidirectional reflectance distribution functions at various wavelengths and distances from the imaging device, are embedded in the transfer function from a light source to a light sensor. Furthermore, light transfer is linear. Thus, SFTI introduces new inverse problems with at least portions of the forward models being linear. The investigators will apply and extend analysis techniques developed for other imaging methods, such as computed tomography and synthetic aperture radar, to develop theoretical foundations for SFTI. Analysis will inspire and be informed by proof-of-concept experiments.