Abstract: A “Text Rectifier” provides various techniques for processing selected regions of an image containing text or characters by treating those images as matrices of low-rank textures and using a rank minimization technique that recovers and removes image deformations (e.g., affine and projective transforms as well as general classes of nonlinear transforms) while rectifying the text or characters in the image region. Once distortions have been removed and the text or characters rectified, the resulting text is made available for a variety of uses or further processing such as optical character recognition (OCR). In various embodiments, binarization and/or inversion techniques are applied to the selected image regions during the rank minimization process to both improve text rectification and to present the resulting images of text to an OCR engine in a form that enhances the accuracy of the OCR results.

Abstract: A “Transform Invariant Low-Rank Texture” (TILT) Extractor, referred to as a “TILT Extractor” accurately extracts both textural and geometric information defining regions of low-rank planar patterns from 2D images of a scene, thereby enabling a large range of image processing applications. Unlike conventional feature extraction techniques that rely on point-based features, the TILT Extractor extracts texture regions from an image and derives global correlations or transformations of those regions in 3D (e.g., transformations including translation, rotation, reflection, skew, scale, etc.). These image domain transformations inherently provide information relative to an automatically determinable camera viewing direction. In other words, the TILT Extractor extracts low-rank regions and geometric correlations describing domain transforms of those regions relative to arbitrary camera viewpoints.

Abstract: A “Camera Calibrator” provides various techniques for recovering intrinsic camera parameters and distortion characteristics by processing a set of one or more input images. These techniques are based on extracting “Transform Invariant Low-Rank Textures” (TILT) from input images using high-dimensional convex optimization tools for matrix rank minimization and sparse signal recovery. The Camera Calibrator provides a simple, accurate, and flexible method to calibrate intrinsic parameters of a camera even with significant lens distortion, noise, errors, partial occlusions, illumination and viewpoint change, etc. Distortions caused by the camera can then be automatically corrected or removed from images. Calibration is achieved under a wide range of practical scenarios, including using multiple images of a known pattern, multiple images of an unknown pattern, single or multiple images of multiple patterns, etc.

Abstract: An embodiment of the present invention relates to a method for detection of short circuit conditions in an LED array having one or more LED strings, each of which includes one or more LED devices. The method includes determining a minimum voltage that is the lowest of voltages associated with cathode terminals of the one or more LED strings. The method also includes determining if said minimum voltage is between a lower limit voltage and an upper voltage limit. If said minimum voltage is between the lower limit voltage and the upper voltage limit, then a result of a short circuit testing can be considered valid. Here, the short circuit testing includes comparing a sampled voltage associated with a cathode voltage of one of the LED strings with a short-circuit reference voltage.