CIF: Small: Lens-Free Imaging: Can Signal Processing Replace Lenses?

相机的基本设计几个世纪以来一直保持不变。为了获取图像，使用透镜将来自场景的光聚焦到图像传感器上。这种设计在广泛的应用中为用户提供了很好的服务，镜头构成了当前成像实践的基石。不幸的是，透镜也引入了许多限制。首先，虽然图像传感器通常很薄，但由于透镜的复杂性以及实现聚焦所需的透镜和传感器之间的大距离，相机最终会很厚。第二，而摩尔？虽然随着时间的推移，图像传感器的成本呈指数级下降，但镜头和相机并没有从这种指数级缩放中受益，特别是在红外线和紫外线波长更远的地方，无法使用廉价的玻璃和塑料。第三，基于镜头的相机总是需要后期组装，导致制造效率低下。在这个项目中，PI开发了完全免除镜头的新相机架构。无透镜相机保留了基于透镜的相机的高光通量，具有薄的形状因子，并且在宽光谱范围内操作时易于直接制造。该设计将透镜替换为一系列编码掩模，这些掩模几乎直接放置在裸露的传统传感器顶部，并使用计算算法从传感器测量中恢复图像。该项目的目标是一个基于现代信号处理的框架，用于设计、优化和开发无透镜和无折射光学成像系统，该系统将建立成像的基本限制。这将彻底改变成像能力，并首次实现可以使用传统半导体制造工具直接制造的薄型相机。

The basic design of the camera has remained unchanged for centuries. To acquire an image, light from the scene is focused using a lens onto an image sensor. This design has served users well in a broad range of applications, with lenses forming the bedrock of current imaging practice. Unfortunately, lenses also introduce a number of limitations. First, while image sensors are typically thin, cameras end up being thick due to the lens complexity and the large distance between the lens and sensor required to achieve focus. Second, while Moore?s Law has cut the cost of image sensors exponentially over time, lenses, and thus cameras, do not benefit from this exponential scaling, particularly at wavelengths further into the infrared and ultraviolet, where inexpensive glass and plastics cannot be used. Third, lens-based cameras invariably require post-fabrication assembly, resulting in manufacturing inefficiencies.In this project, the PIs develop new camera architectures that dispense with lenses completely. Lens-free cameras retain the high light-throughput of lens-based cameras, have a thin form factor, and are amenable to direct fabrication while operating over a wide spectral range. The design replaces the lens with a series of coded masks placed almost immediately atop a bare conventional sensor and uses a computational algorithm to recover the image from the sensor measurements. The goal of this project is a modern signal processing based framework for the design, optimization and development of lens free and refractive optics-free imaging systems that will establish the fundamental limits of imaging with such systems. This will revolutionize imaging capabilities and, for the first time, enable thin, cameras that can directly be fabricated using traditional semiconductor fabrication tools.