Abstract: A video stream is digitally encoded such that the rate at which individual segments of data are encoded varies according to the amount of data required to generate each segment. Frames are selectively omitted from transmission (32) such that the cumulative frame rate does not fall below a predetermined value. This process can be used to ensure that the next frame to be displayed is always available in the buffer store 6 associated with the decoder (2). The decoder (2) is arranged to identify where frames have been omitted from the decoded transmission, and to perform a resynchronisation (7) on the decoded stream by comparison between time stamps in the video stream and a corresponding audio stream. Resynchronisation may be performed by extending the durations of individual frames, or by repeating frames.

Abstract: A tubular luminaire efficiently utilizes the light of a line of high-brightness unlensed LEDs to reproduce the homogeneous appearance of a neon tube. The transparent tube has an annular cross-section suitable for cost-effective manufacturing by extrusion. The LEDs are mounted in a line on a circuit board that can be positioned either inside or outside the tube. Their light shines into a cylindrical groove, thereby entering within the material of the tube. Above the groove, the wall of the tube has a spiral shape that reflects the light laterally so that it stays within the annular tube for a considerable path length. Volume scattering by a low density of scattering inclusions causes the light to escape as a homogenous glow. Alternatively, mild surface scattering from the inside surface can be used.

Abstract: Faults resulting in reception of a still, but unknown, frame are recognized by comparing each received frame of the video signal with its predecessor, incrementing a counter in the event that the difference between the frames falls below a threshold; and generating an alarm signal in the event that the count of the counter exceeds a predetermined count. Other types of fault such as loss of signal (i.e. reception of just noise) are recognized by incrementing the counter whenever the difference exceeds a threshold. Similar results may be obtained by instead the monitoring quantization step size and/or number of transmitted bits of a digitally coded signal, and noting that it falls below, or exceeds, a threshold. A preferred option is to compute a complexity measure, being a monotonically increasing function (e.g the product) of the quantization step size and of the number of coded bits and compare this with the threshold value.

Abstract: A method, system and device are provided for pre-filtering device for filtering a video signal prior to digitally encoding. The method includes receiving at least one input picture and at least one reconstructed picture from an encoding process and performing an in-loop temporal filtering process using at least one input picture and at least one reconstructed picture from an encoding process to output a pre-filtered video signal for use in an encoding process. The result is enabling an encoding process to produce an output with increased temporal correlation between adjacent pictures regardless of the coding type, since the artifacts introduced by the encoding process are also considered by the process.

Abstract: An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well, including a phosphor coating. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations.

Abstract: Recorded material such as video is transmitted in compressed form to a receiver, which has a buffer for smoothing differences between the data rate received and that consumed by a decoder that follows. The whole of the recording is analysed to determine a point at which to commence playing such that no buffer underflow can occur; the decoder commences playing only when this point has been reached.

Abstract: Data for presentation in real time, such as a video or audio sequence, is available on different encoded versions having different degrees Of compression. In order to assess, during transmission of one version, the feasibility of switching to another version, given the data rate known to be available at the time, a server computes, for a candidate version, in respect of at least one portion thereof that has not yet been sent, the maximum value of a timing error that would occur if any number of portions starting with that portion to be sent at the available rate. The selection of the same or a different version for continuing transmission is taken in dependence on a comparison between the computed error and the current state of a receiving buffer. Error values may be computed in advance for a range of transmitting rates, stored and later retrieved for use in estimating an error value corresponding to the actual transmitting rate.

Abstract: A passive electro-optical tracker uses a two-band IR intensity ratio to discriminate high-speed projectiles and obtain a speed estimate from their temperature, as well as determining the trajectory back to the source of fire. In an omnidirectional system a hemispheric imager with an MWIR spectrum splitter forms two CCD images of the environment. Three methods are given to determine the azimuth and range of a projectile, one for clear atmospheric conditions and two for nonhomogeneous atmospheric conditions. The first approach uses the relative intensity of the image of the projectile on the pixels of a CCD camera to determine the azimuthal angle of trajectory with respect to the ground, and its range. The second calculates this angle using a different algorithm. The third uses a least squares optimization over multiple frames based on a triangle representation of the smeared image to yield a real-time trajectory estimate.

Abstract: A system (5) processes pixel data representing one of a first image compressed according to a first compression algorithm and a second image compressed according to a second compression algorithm. A pixel analyzer (32) generates first and second selection signals depending on the type of image. A processing module (40) includes first circuits arranged to process the data in response to a first selection signal and second circuits arranged to process the data in response to a second selection signal. A control processor (10) enables the first circuits in response to the first selection signal and enables the second circuits in response to the second selection signal.

Abstract: The present embodiments provide systems, backlights, films, apparatuses and methods of generating back lighting. Some embodiments provide backlights that include a cavity with at least one interior light source and diffusely reflecting wall of high reflectivity, a top surface with multiple intermittently spaced holes allowing exit of light generated by the light sources, and external collimators extending from each of the holes such that the external collimators spatially expand and angularly narrow the light exiting the holes.

Abstract: The present embodiments provide methods and systems for use in providing enhanced illumination. Some embodiments include at least two light sources and one or more smoothly rotating wheels, where the one or more wheels comprises at least one mirror sector, the circumferential portion of the mirror sector is the inverse of the number of said sources, a first source of the sources is so disposed that the mirror sector reflects light from the first source into a common output path, where the first source pulsing such that a duty cycle of the first source corresponds to a time the mirror sector reflects light from the first source into the common output path.

Abstract: A tubular luminaire efficiently utilizes the light of a line of high-brightness unlensed LEDs to reproduce the homogeneous appearance of a neon tube. The transparent tube has an annular cross-section suitable for cost-effective manufacturing by extrusion. The LEDs are mounted in a line on a circuit board that can be positioned either inside or outside the tube. Their light shines into a cylindrical groove, thereby entering within the material of the tube. Above the groove, the wall of the tube has a spiral shape that reflects the light laterally so that it stays within the annular tube for a considerable path length. Volume scattering by a low density of scattering inclusions causes the light to escape as a homogenous glow. Alternatively, mild surface scattering from the inside surface can be used.

Abstract: A method and system are provided where image data is encoded in the spatial domain, and transformed in a two dimensional transform process to thereby recover a frequency domain representation of the image data. The frequency domain representation is then quantized to obtain an integer representation. The integer representation is ordered by frequency. Then, the hi-frequency coefficients are recreated and intelligently randomized at selective frequencies. This provides high quality encoded picture results, with fewer artifacts than those that would result from conventional approaches afflicted by artifacts due to loss of high frequencies.

Abstract: High-concentration photovoltaic concentrators can utilize much more expensive high-efficiency cells because they need so much less of them, but much of the solar resource is left ungathered thereby. The main cell is at the focal spot of the concentrator. Low-cost secondary solar cells are now added to the concentrator, surrounding the main cell. Diffuse skylight and misdirected normal rays irradiate these secondary cells, adding to output. Also, the power plant can have output on cloudy days, unlike conventional concentrators. As cell costs fall relative to other costs, this system becomes economically superior to both flat-plate and concentrator systems.

Abstract: The present embodiments provide methods and systems for use in providing enhanced illumination. Some embodiments include at least two light sources and one or more smoothly rotating wheels, where the one or more wheels comprises at least one mirror sector, the circumferential portion of the mirror sector is the inverse of the number of said sources, a first source of the sources is so disposed that the mirror sector reflects light from the first source into a common output path, where the first source pulsing such that a duty cycle of the first source corresponds to a time the mirror sector reflects light from the first source into the common output path.

Abstract: The present embodiments provide systems, backlights, films, apparatuses and methods of generating back lighting. Some embodiments provide backlights that include a cavity with at least one interior light source and diffusely reflecting wall of high reflectivity, a top surface with multiple intermittently spaced holes allowing exit of light generated by the light sources, and external collimators extending from each of the holes such that the external collimators spatially expand and angularly narrow the light exiting the holes.

Abstract: In some embodiments, an apparatus for use generating illumination is provided that comprises a reflective base, a first light source positioned proximate the reflective base, and a reimaging reflector positioned partially about the first light source, where a percentage of light emitted from the first light source is reflected from the reimaging reflector to the reflective base adjacent the first light source establishing a first real image. The reimaging reflector can further comprise a first sector of a first ellipsoid and a second sector of a second ellipsoid, where the first and second sectors establish the first and a second real image. Further embodiments provide a lens that includes a reimaging reflector that receives light and reflects the light establishing a first real image. The reimaging reflector can further comprise a plurality of sectors that reflect light to establish first and second real images.

Abstract: An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well, including a phosphor coating. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations.

Abstract: In some embodiments, an apparatus for use generating illumination is provided that comprises a reflective base, a first light source positioned proximate the reflective base, and a reimaging reflector positioned partially about the first light source, where a percentage of light emitted from the first light source is reflected from the reimaging reflector to the reflective base adjacent the first light source establishing a first real image. The reimaging reflector can further comprise a first sector of a first ellipsoid and a second sector of a second ellipsoid, where the first and second sectors establish the first and a second real image. Further embodiments provide a lens that includes a reimaging reflector that receives light and reflects the light establishing a first real image. The reimaging reflector can further comprise a plurality of sectors that reflect light to establish first and second real images.

Abstract: Faults resulting in reception of a still, but unknown, frame are recognised by comparing each received frame of the video signal with its predecessor, incrementing a counter in the event that the difference between the frames falls below a threshold; and generating an alarm signal in the event that the count of the counter exceeds a predetermined count. Other types of fault such as loss of signal (i.e. reception of just noise) are recognised by incrementing the counter whenever the difference exceeds a threshold. Similar results may be obtained by instead the monitoring quantisation step size and/or number of transmitted bits of a digitally coded signal, and noting that it falls below, or exceeds, a threshold. A preferred option is to compute a complexity measure, being a monotonically increasing function (e.g the product) of the quantisation step size and of the number of coded bits and compare this with the threshold value.