Abstract: A method of chromatically-corrected image demosaicing for a sensor with a colour filter array (CFA) such as a Bayer filter array. The demosaicing makes use of local chromatic aberration correction data to determine chromatically-corrected pixel positions for spatial interpolation. In implementations a chromatically-corrected quadratic adjustment is also applied.

Abstract: An image capture system comprises a camera configured to capture an image of a whiteboard, or similar, viewed from an acute angle. A linear polarizer has a surface substantially perpendicular to a plane of the board and an axis of polarization substantially perpendicular to the plane of the board or within 30° of the perpendicular to the plane of the board. The camera is configured to capture the image of the board through the polarizer. A normal to the polarizer is directed in a different direction to a direction defined by an optic axis of the camera.

Abstract: A method of chromatically-corrected image demosaicing for a sensor with a colour filter array (CFA) such as a Bayer filter array. The demosaicing makes use of local chromatic aberration correction data to determine chromatically-corrected pixel positions for spatial interpolation. In implementations a chromatically-corrected quadratic adjustment is also applied.

Abstract: Various approaches related to capturing content of erasable boards are discussed herein.

Abstract: An image capture system comprises a camera configured to capture an image of a whiteboard, or similar, viewed from an acute angle. A linear polarizer has a surface substantially perpendicular to a plane of the board and an axis of polarization substantially perpendicular to the plane of the board or within 30° of the perpendicular to the plane of the board. The camera is configured to capture the image of the board through the polarizer. A normal to the polarizer is directed in a different direction to a direction defined by an optic axis of the camera.

Abstract: A method of capturing writing or drawing on a whiteboard comprises inputting camera data for a succession of image frames of the whiteboard, and processing data from said image frames to remove parts of the image frames corresponding to parts of a user or user pen writing or drawing on the whiteboard. The processing involves filtering to distinguish between i) motion of the user/user pen parts in the image frames, and ii) writing/drawing image information in the image frames which appears or changes during said writing or drawing but which is thereafter substantially unchanging. The filtered data defines captured writing or drawing from the whiteboard.

Abstract: Various approaches to touch sensing systems are disclosed As an example, a touch sensing system is disclosed that includes: an optical beam source to provide an optical beam; a pair of controllable beam deflectors comprising at least first and second beam deflectors, wherein the first beam deflector is configured to deflect the optical beam through a first angle towards a touch sensing region, and wherein the second beam deflector is configured to deflect scattered light from an object in the touch sensing region through a second angle; a detector, in particular a detector array; and an imaging system to image the deflected scattered light from the second beam deflector onto the detector array. The first and second beam deflectors are controlled in tandem to scan the touch sensing region.

Abstract: Various approaches related to capturing content of erasable boards are discussed herein.

Abstract: We describe a method of capturing writing or drawing on a whiteboard. The method comprises: inputting camera data for a succession of image frames, wherein the camera data is from a camera directed towards the whiteboard and the image frames comprise successive images of the whiteboard from the camera; and user filter processing data from said image frames to remove parts of said image frames corresponding to parts of a user or user pen writing or drawing on said whiteboard. The user-filter processing comprises filtering to distinguish between motion of the user/user pen parts in the image frames and writing/drawing image information in the image frames which appears or changes during said writing or drawing but which is thereafter substantially unchanging. The method outputs writing/drawing data from the user filter-processing, this defining captured writing or drawing from the whiteboard.

Abstract: We describe a touch sensing system projecting light defining a touch sheet above a surface and a camera to capture a touch image of light scattered by a pen intersecting the touch sheet. A signal processor identifies a lateral location of the pen. The pen includes a light source to provide a light signal, and the system also includes two photodiodes to detect the signal from the pen. The touch detection is augmented by modelling the signals received at the photodiodes, dependent on the distance and angle of a pen, and using this to derive a probability of the observed received signals given the pen location determined from the touch sheet. This information can be used, for example, to allocate identities to the pens.

Abstract: We describe a touch sensitive image display device including: an image projector to project a displayed image onto a surface; a touch sensor light source to project a plane of light above the displayed image; a camera to capture a touch sense image from light scattered from the plane of light by an approaching object; and a signal processor to process the touch sense image to identify a location of the object. The touch sensor light source is amplitude modulated, and signal processor is further configured to process a plurality of the touch sense images captured when the touch sensor light source is off to compensate for ambient light in a touch sense image captured when the touch sensor light source is on.

Abstract: A touch sensitive device, the device comprising: a touch sensor light source to project a plane of light above a surface; a camera directed to capture a touch sense image from a region including at least a portion of said plane of light, said touch sense image comprising light scattered from said plane of light by a plurality of said objects simultaneously approaching or touching said surface; a signal processor coupled to said camera, to process a said touch sense image from said camera to identify a lateral location of each of said objects; and an output object position output, to provide output object positions for said plurality of objects; and wherein said signal processor is further configured to: input a succession of said touch sense images; process each said touch sense image to identify a plurality of candidate object touch positions; and filter said candidate object touch positions from said successive touch sense images to link said candidate object touch positions to previously identified output

Abstract: We describe a touch sensing system projecting light defining a touch sheet above a surface and a camera to capture a touch image of light scattered by a pen intersecting the touch sheet. A signal processor identifies a lateral location of the pen. The pen includes a light source to provide a light signal, and the system also includes two photodiodes to detect the signal from the pen. The touch detection is augmented by modelling the signals received at the photodiodes, dependent on the distance and angle of a pen, and using this to derive a probability of the observed received signals given the pen location determined from the touch sheet. This information can be used, for example, to allocate identities to the pens.

Abstract: We describe a touch sensitive image display device. The device comprises: an image projector to project a displayed image onto a surface in front of the device; a touch sensor light source to project light defining a touch sheet above the displayed image; a camera directed to capture a touch sense image comprising light scattered from the touch sheet by an object approaching the displayed image; and a signal processor to process a the touch sense image to identify a location of the object relative to the displayed image. The camera is able to capture an image projected by the image projector, the image projector is configured to project a calibration image, and the device includes a calibration module configured to use a calibration image from the projector, captured by the camera, to calibrate locations in said captured touch sense image with reference to said displayed image.

Abstract: A touch sensitive device, the device comprising: a touch sensor light source to project a plane of light above a surface: a camera directed to capture a touch sense image from a region including at least a portion of said plane of light, said touch sense image comprising light scattered from said plane of light by a plurality of said objects simultaneously approaching or touching said surface; a signal processor coupled to said camera, to process a said touch sense image from said camera to identify a lateral location of each of said objects; and an output object position output, to provide output object positions for said plurality of objects; and wherein said signal processor is further configured to: input a succession of said touch sense images; process each said touch sense image to identify a plurality of candidate object touch positions; and filter said candidate object touch positions from said successive touch sense images to link said candidate object touch positions to previously identified output

Abstract: The invention relates to techniques for speckle reduction in holographic optical systems, in particular holographic image display systems. We describe a holographic image display system for displaying an image holographically on a display surface, the system including: a spatial light modulator (SLM) to display a hologram; a light source to illuminate said displayed hologram; projection optics to project light from said illuminated displayed hologram onto said display surface to form a holographically generated two-dimensional image, said projection optics being configured to form, at an intermediate image surface, an intermediate two-dimensional image corresponding to said holographically generated image; a diffuser located at said intermediate image surface; and an actuator mechanically coupled to said diffuser to, in operation, move said diffuser to randomise phases over pixels of said intermediate image to reduce speckle in an image displayed by the system.

Abstract: A low cost x-y digitising system is described for use in consumer electronic devices, such as portable digital assistants, mobile telephones, web browsers and the like. The digitiser includes a resonant stylus, an excitation winding for energising the resonant stylus and a set of sensor windings for sensing the signal generated by the stylus, from which the x-y position of the stylus is determined. A novel stylus design is described together with novel digitiser windings and novel excitation and processing circuitry.