Abstract:
In exemplary implementations of this invention, cataracts in the human eye are assessed and mapped by measuring the perceptual impact of forward scattering on the foveal region. The same method can be used to measure scattering/blocking media inside lenses of a camera. Close-range anisotropic displays create collimated beams of light to scan through sub-apertures, scattering light as it strikes a cataract. User feedback is accepted and analyzed, to generate maps for opacity, attenuation, contrast and sub-aperture point-spread functions (PSFs). Optionally, the PSF data is used to reconstruct the individual's cataract-affected view.
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, this invention is a tool for subjective assessment of the visual acuity of a human eye. A microlens or pinhole array is placed over a high-resolution display. The eye is brought very near to the device. Patterns are displayed on the screen under some of the lenslets or pinholes. Using interactive software, a user causes the patterns that the eye sees to appear to be aligned. The software allows the user to move the apparent position of the patterns. This apparent motion is achieved by pre-warping the position and angle of the ray-bundles exiting the lenslet display. As the user aligns the apparent position of the patterns, the amount of pre-warping varies. The amount of pre-warping required in order for the user to see what appears to be a single, aligned pattern indicates the lens aberration of the eye.
Abstract:
In exemplary implementations of this invention, a time of flight camera (ToF camera) can estimate the location, motion and size of a hidden moving object, even though (a) the hidden object cannot be seen directly (or through mirrors) from the vantage point of the ToF camera (including the camera's illumination source and sensor), and (b) the object is in a visually cluttered environment. The hidden object is a NLOS (non-line-of-sight) object. The time of flight camera comprises a streak camera and a laser. In these exemplary implementations, the motion and absolute locations of NLOS moving objects in cluttered environments can be estimated through tertiary reflections of pulsed illumination, using relative time differences of arrival at an array of receivers. Also, the size of NLOS moving objects can be estimated by backprojecting extremas of NLOS moving object time responses.
Abstract:
In an exemplary implementation of this invention, light from a scattering scene passes through a spatial light attenuation pattern and strikes a sensor plane of a camera. Based on said camera's measurements of the received light, a processing unit calculates angular samples of the received light. Light that strikes the sensor plane at certain angles comprises both scattered and directly transmitted components; whereas light that strikes at other angles comprises solely scattered light. A processing unit calculates a polynomial model for the intensity of scattered-only light that falls at the latter angles, and further estimates the direct-only component of the light that falls at the former angles. Further, a processing unit may use the estimated direct component to calculate a reconstructed 3D shape, such as a 3D shape of a finger vein pattern, using an algebraic reconstruction technique.
Abstract:
Glare is reduced by acquiring an input image with a camera having a lens and a sensor, in which a pin-hole mask is placed in close proximity to the sensor. The mask localizes the glare at readily identifiable pixels, which can then be filtered to produce a glare reduce output image.
Abstract:
A method and system determines a 3D pose of an object in a scene. Depth edges are determined from a set of images acquired of a scene including multiple objects while varying illumination in the scene. The depth edges are linked to form contours. The images are segmented into regions according to the contours. An occlusion graph is constructed using the regions. The occlusion graph includes a source node representing an unoccluded region of an unoccluded object in scene. The contour associated with the unoccluded region is compared with a set of silhouettes of the objects, in which each silhouette has a known pose. The known pose of a best matching silhouette is selected as the pose of the unoccluded object.
Abstract:
A method and system deblurs images acquired of a scene by a camera. A light field acquired of a scene is modulated temporally according to a sequence of ons and offs. The modulated light field is integrated by a sensor of a camera during an exposure time to generate an encoded input image. The encoded input image is decoded according to a pseudo-inverse of a smearing matrix to produce a decoded output image having a reduced blur.
Abstract:
A method detects silhouette edges in images. An ambient image is acquired of a scene with ambient light. A set of illuminated images is also acquired of the scene. Each illuminated image is acquired with a different light source illuminating the scene. The ambient image is combined with the set of illuminated to detect cast shadows, and silhouette edge pixels are located from the cast shadows.
Abstract:
A method generates a high dynamic range image by first acquiring a set of images of a scene illuminated by different lighting conditions. The set of images are then combined to generate a high dynamic range image.