In this paper we propose a novel, highly flexible camera. The  Virtually all cameras today have lenses. Lenses are useful as they focus the light from the scene on the image plane to form bright and sharp images. We are so accustomed to cameras with lenses that we often overlook their fundamental limitation; lenses severely constrain the geometric and radiometric mapping from the scene to the image. The goal of this paper is to develop a new approach to imaging that facilitates a new class of mappings from the scene to the image, thereby enabling the camera to perform a wide set of imaging functionalities. We propose in this paper a novel, flexible video camera that does not have a lens. The camera design is simple. It consists of two components, an image detector and a special aperture, that are placed at a small distance apart. Figure 1 Conventional apertures can be realized as a special case of this aperture, by using a constant binary transmittance pattern. Figure 1(b) show the aperture in its complete form. A stack of several controllable light attenuating layers at different distances from the detector are used. One way to implement controllable attenuating layers is by using liquid crystal sheets 1 . Figure 2 highlights the difference between a conventional lens camera and our lensless camera. An ideal lens camera, shown in Figure 2(a) , focuses the scene on the image plane. Each point on the image detector integrates light emanating from a single point in the scene. Therefore, the aperture influences only the total brightness of the image and the local blur in defocused areas. In contrast, our lensless imaging system, shown in Figure 2(b) , has no focusing. Each point on the image detector integrates light emanating from the entire field of view. Prior to the integration, the 2D light field associated with each image point is modulated by the attenuating aperture. Therefore, it is the aperture that determines the geometry and photometry of the imaging process. We show that a careful selection of the transmittance pattern of the aperture makes it possible to modulate the light in useful ways that cannot be achieved with conventional cameras. Moreover, since the aperture is controllable, the imag-1 Other spatial light modulators can be used as well such as a Digital Micromirror Device (DMD) or Liquid Crystal On Silicon (LCOS).
Zomet & Nayar REF proposed a volume of light attenuating layers that are controllable in space and time for a lensless imaging system and showed a variety of nonconventional imaging functionalities such as split field of view.
Lensless Imaging with a Controllable Aperture
2006 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'06)
2006 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'06)
Computer Science