Abstract: A back-lit screen comprising: a rigid frame extending around the periphery of the screen and having a front face, the front face having an interior face which defines an opening, and an outer face which defines the exterior contour of the frame transversely to the opening; and a translucent sheet extending across the opening; the frame being configured so that over at least a part of the periphery of the screen the forward-most part of the interior face is coincident with the exterior contour of the frame.

Abstract: A display controller configured to cause a display to show successive frames of a main presentation and to intermittently display a predetermined map of indicia between the frames of the main presentation, whereby a device can determine its location.

Abstract: A method for forming a processed video stream, comprising: capturing a first part of an input video stream using a camera; transmitting the first part of the video stream to a processing facility remote from the camera; at the processing facility, designating a first sub-region of the first part of the video stream for further processing; in dependence on the designation of a first sub-region, forming a first cropped video stream by cropping the first part of the video stream to that sub-region; forming the processed video stream incorporating the first cropped video stream.

Abstract: A controller for a video camera, the controller comprising: an input for receiving a focus command indicative of a focus distance; and one or more outputs for transmitting a first signal for controlling the focus of a lens of the camera and a second signal indicative of the focus distance indicated by the focus command; the controller being configured to determine a focus limit and to transmit the first signal so as to command the camera to adjust its focus to the distance indicated by the focus command only if that distance does not exceed the focus limit.

Abstract: A system for capturing a video stream, the system comprising: a camera; and an encoding device configured to store video captured by the camera together with metadata indicating a location in the video at which a predesignated substitution object appears.

Abstract: A lens calibration system for calibrating a lens of an image capture device, the lens calibration system comprising: a processor configured to receive from the image capture device a series of image frames of a scene at different rotational positions of the image capture device; The processor being configured to: Identify in the series of image frames elements representing a first marker located at a first known distance from the image capture device and a second marker located at a second known distance from the image capture device, the first and the second known distances being different to one another; track the identified elements representing each marker across the series of image frames; process the tracked elements to determine a characteristic parameter of the lens of the image capture device; and build a lens model for the image capture device in dependence on the determined characteristic parameter of the lens.

Abstract: A method for monitoring a work process in which a workpiece is worked on by a tool, the method comprising: providing an irregular pattern of indicia remote from the workpiece and the tool; imaging the indicia by an imaging device carried by the workpiece and thereby estimating the location of the workpiece with respect to the indicia; imaging the indicia by an imaging device carried by the tool and thereby estimating the location of the tool with respect to the indicia; and correlating the location of the workpiece and the tool to estimate an operation performed by the tool on the workpiece.

Abstract: A method for forming augmented image data, the method comprising: forming a primary image feed showing a subject illuminated by a lighting unit; estimating the location of the lighting unit; receiving overlay data defining an overlay of three-dimensional appearance; rendering the overlay data in dependence on the estimated location to form an augmentation image feed; and overlaying the augmentation image feed on the primary image feed to form a secondary image feed.

Abstract: An optical navigation system comprising a camera oriented to face towards a plurality of markers located at spaced apart locations from the camera, calculating means adapted to calculate an angle subtended between pairs of markers, the subtended angles being calculated by monitoring the pixel locations of the markers in a series of images captured by the camera, the optical navigation system additionally comprising means for creating a three-dimensional model whereby the location of the camera relative to the markers is determined by triangulating the subtended angles in the three-dimensional model.

Abstract: An optical navigation system comprising a camera oriented to face towards a plurality of markers located at spaced apart locations from the camera, calculating means adapted to calculate an angle subtended between pairs of markers, the subtended angles being calculated by monitoring the pixel locations of the markers in a series of images captured by the camera, the optical navigation system additionally comprising means for creating a three-dimensional model whereby the location of the camera relative to the markers is determined by triangulating the subtended angles in the three-dimensional model.