Abstract: A structured light pattern is projected onto a scene using pulses of light emitted by light emitting diodes (LEDs) of the projector, wherein during the pulses of the LEDs, the LEDs are driven at an overdrive current when the LEDS are ON. A sensor of a camera only integrates light from the scene during the pulses to acquire images of the scene.

Abstract: A rotary encoder includes a single read-head and a circular scale. The encoder is self-calibrated by acquiring calibration samples with the read-head for rotational angles of the circular scale, and estimating spatial frequency and spatial distortion parameters of the encoder from the calibration samples.

Abstract: A position is determined by sensing a signal corresponding to a subsequence of marks in a non-periodic sequence of the marks on a scale. A coarse position PA is determined by matching the subsequence with all possible subsequences of the non-periodic sequence. Zero-crossings corresponding to rising edges of the signal and zero-crossings corresponding to falling edges of the signal are detected. An incremental position Pi is determined using the zero-crossings. The coarse and the incremental position are summed to obtain the position.

Abstract: During pre-processing, a 3D model of the object is rendered for various poses by arranging virtual point light sources around the lens of a virtual camera. The shadows are used to obtain oriented depth edges of the object illuminated from multiple directions. The oriented depth edges are stored in a database. A camera acquires images of the scene by casting shadows onto the scene from different directions. The scene can include one or more objects arranged in arbitrary poses with respect to each other. The poses of the objects are determined by comparing the oriented depth edges obtained from the acquired images to the oriented depth edges stored in the database. The comparing evaluates, at each pixel, a cost function based on chamfer matching, which can be speed up using downhill simplex optimization.

Abstract: A network in an environment includes passive sensors with associated sensor identification numbers. A set of active badges with associated badge identification numbers, wherein each badge is associated with an object, and wherein a particular sensor broadcasts a packet in response to detecting a particular object, wherein the packet includes the sensor identification number and a time, and only if the particular object is associated with a particular badge then the badge appends the badge identification number to the packet and broadcasts the appended packet, and the particular sensor receives and rebroadcasts the appended packet for further processing to passively and actively monitor the environment.

Abstract: A method identifies an unknown face in an input image using reference images of known faces. A Haar-like feature vector is extracted from each image. The vectors are compressed. An L1 norm is determined between the compressed feature vector of the input image and each compressed feature vector from the set of reference images to determine a most similar reference image. The identity of the face associated with the most similar reference image is assigned as the identity of the unknown face in the input image.

Abstract: A network in an environment includes passive sensors with associated sensor identification numbers. A set of active badges with associated badge identification numbers, wherein each badge is associated with an object, and wherein a particular sensor broadcasts a packet in response to detecting a particular object, wherein the packet includes the sensor identification number and a time, and only if the particular object is associated with a particular badge then the badge appends the badge identification number to the packet and broadcasts the appended packet, and the particular sensor receives and rebroadcasts the appended packet for further processing to passively and actively monitor the environment.

Abstract: During pre-processing, a 3D model of the object is rendered for various poses by arranging virtual point light sources around the lens of a virtual camera. The shadows are used to obtain oriented depth edges of the object illuminated from multiple directions. The oriented depth edges are stored in a database. A camera acquires images of the scene by casting shadows onto the scene from different directions. The scene can include one or more objects arranged in arbitrary poses with respect to each other. The poses of the objects are determined by comparing the oriented depth edges obtained from the acquired images to the oriented depth edges stored in the database. The comparing evaluates, at each pixel, a cost function based on chamfer matching, which can be speed up using downhill simplex optimization.

Abstract: A method identifies an unknown face in an input image using reference images of known faces. A Haar-like feature vector is extracted from each image. The vectors are compressed. An L1 norm is determined between the compressed feature vector of the input image and each compressed feature vector from the set of reference images to determine a most similar reference image. The identity of the face associated with the most similar reference image is assigned as the identity of the unknown face in the input image.

Abstract: Techniques are disclosed for correcting the exposure of a digital image. An exposure predictor may be generated based on a set of images for which ground truth data are known. After identifying an optimal set of features, the exposure of the digital image may be corrected by extracting values of the selected optimal features from the image, using the predictor to predict a desired exposure correction for the image, and correcting the exposure of the image by the predicted desired amount. Exposure correction is based on a model that relates intensity of light in the world to the RGB digits of the digital image. The model comprises a gamma function that models the response of a typical monitor and a S-shaped curve that compresses the large dynamic range of the world to the small dynamic range of the RGB digit space.

Abstract: A multicolor imaging system is described wherein at least two, and preferably three, different image-forming layers of a thermal imaging member are addressed at least partially independently by a thermal printhead or printheads from the same surface of the imaging member by controlling the temperature of the thermal printhead(s) and the time thermal energy is applied to the image-forming layers. Each color of the thermal imaging member can be printed alone or in selectable proportion to the other color(s). Novel thermal imaging members are also described.

Abstract: Techniques are disclosed for performing color correction in a color printer. An RGB test image is printed to produce a printed calibration image. Colors in the printed calibration image are measured and compared to expected color values. A color corrector generates a printer lookup table (LUT) based on this comparison. The LUT may be generated based on models of the printer's print engine and previous LUTs. The color corrections are applied to subsequent print jobs to improve the quality of color output. Color measurement and correction may be performed using a closed-loop system contained within the printer that includes a color measurement device (such as a scanner) and a computer.

Abstract: In a rear projection television, cathode ray tubes are mounted inside an enclosure so that each cathode ray tube projects output images onto a rear projection screen using a corresponding electron beam. Calibration images are generated for each cathode ray tube. A camera, also mounted inside the enclosure, acquires an input image of each calibration image. A distortion in each input image is measured, and the output images of the cathode ray tubes are corrected by adjusting the signals controlling the corresponding electron beams according to the distortion.

Abstract: A multicolor imaging system is described wherein at least two, and preferably three, different image-forming layers of a thermal imaging member are addressed at least partially independently by a thermal printhead or printheads from the same surface of the imaging member by controlling the temperature of the thermal printhead(s) and the time thermal energy is applied to the image-forming layers. Each color of the thermal imaging member can be printed alone or in selectable proportion to the other color(s). Novel thermal imaging members are also described.