Abstract: In exemplary implementations of this invention, light from a light field projector is transmitted through an angle-expanding screen to create a glasses-free, 3D display. The display can be horizontal-only parallax or full parallax. In the former case, a vertical diffuser may positioned in the optical stack. The angle-expanding screen may comprise two planar arrays of optical elements (e.g., lenslets or lenticules) separated from each other by the sum of their focal distances. Alternatively, a light field projector may project light rays through a focusing lens onto a diffuse, transmissive screen. In this alternative approach, the light field projector may comprise two spatial light modulators (SLMs). A focused image of the first SLM, and a slightly blurred image of the second SLM, are optically combined on the diffuser, creating a combined image that has a higher spatial resolution and a higher dynamic range than either of two SLMs.

Abstract: In exemplary implementations of this invention, an automultiscopic display device includes (1) one or more spatially addressable, light attenuating layers, and (2) a controller which is configured to perform calculations to control the device. In these calculations, tensors provide sparse, memory-efficient representations of a light field. The calculations include using weighted nonnegative tensor factorization (NTF) to solve an optimization problem. The NTF calculations can be sufficiently efficient to achieve interactive refresh rates. Either a directional backlight or a uniform backlight may be used. For example, the device may have (1) a high resolution LCD in front, and (2) a low resolution directional backlight. Or, for example, the device may have a uniform backlight and three or more LCD panels. In these examples, all of the LCDs and the directional backlight (if applicable) may be time-multiplexed.

Abstract: In exemplary implementations of this invention, a light field camera uses a light field dictionary to reconstruct a 4D light field from a single photograph. The light field includes both angular and spatial information and has a spatial resolution equal to the spatial resolution of the imaging sensor. Light from a scene passes through a coded spatial light modulator (SLM) before reaching an imaging sensor. Computer processors reconstruct a light field. This reconstruction includes computing a sparse or compressible coefficient vector using a light field dictionary matrix. Each column vector of the dictionary matrix is a light field atom. These light field atoms each, respectively, comprise information about a small 4D region of a light field. Reconstruction quality may be improved by using an SLM that is as orthogonal as possible to the dictionary.

Abstract: In exemplary implementations of this invention, an automultiscopic display device includes (1) one or more spatially addressable, light attenuating layers, and (2) a controller which is configured to perform calculations to control the device. In these calculations, tensors provide sparse, memory-efficient representations of a light field. The calculations include using weighted nonnegative tensor factorization (NTF) to solve an optimization problem. The NTF calculations can be sufficiently efficient to achieve interactive refresh rates. Either a directional backlight or a uniform backlight may be used. For example, the device may have (1) a high resolution LCD in front, and (2) a low resolution directional backlight. Or, for example, the device may have a uniform backlight and three or more LCD panels. In these examples, all of the LCDs and the directional backlight (if applicable) may be time-multiplexed.

Abstract: In exemplary implementations of this invention, a flat screen device displays a 3D scene. The 3D display may be viewed by a person who is not wearing any special glasses. The flat screen device displays dynamically changing 3D imagery, with a refresh rate so fast that the device may be used for 3D movies or for interactive, 3D display. The flat screen device comprises a stack of LCD layers with two crossed polarization filters, one filter at each end of the stack. One or more processors control the voltage at each pixel of each LCD layer, in order to control the polarization state rotation induced in light at that pixel. The processor employs an algorithm that models each LCD layer as a spatially-controllable polarization rotator, rather than a conventional spatial light modulator that directly attenuates light. Color display is achieved using field sequential color illumination with monochromatic LCDs.

Abstract: In exemplary implementations of this invention, a flat screen device displays a 3D scene. The 3D display may be viewed by a person who is not wearing any special glasses. The flat screen device displays dynamically changing 3D imagery, with a refresh rate so fast that the device may be used for 3D movies or for interactive, 3D display. The flat screen device comprises a stack of LCD layers with two crossed polarization filters, one filter at each end of the stack. One or more processors control the voltage at each pixel of each LCD layer, in order to control the polarization state rotation induced in light at that pixel. The processor employs an algorithm that models each LCD layer as a spatially-controllable polarization rotator, rather than a conventional spatial light modulator that directly attenuates light. Color display is achieved using field sequential color illumination with monochromatic LCDs.

Abstract: An imaging method comprises acquiring image data in which image components are spatially modulated at distinct spatial frequencies, transforming the image data into the Fourier domain and separating the image components in the Fourier domain. The image components may be transformed into the spatial domain. The image components may comprise different colors. In some embodiments saturated pixels are reconstructed by performing an optimization based on differences between image copies in the Fourier domain. Imaging apparatus may perform the imaging methods.