Abstract: When mixing cutting between video cameras viewing a common scene from different viewpoints, geometric transforms that vary from image to image are applied to one or both camera outputs so as to create an apparent point of view that moves along on a path joining the viewpoints of the cameras.

Abstract: The intended display aspect-ratio for video is determined automatically by analyzing an image to identify image blocks resulting from prior block-based processing of the video; comparing horizontal and vertical dimensions of those image blocks with horizontal and vertical dimensions of the image, with black border regions excluded as necessary; and determining from that comparison a display aspect ratio for the video.

Abstract: First image data at a lower sampling frequency is up-sampled in a sampling ratio N:M to a higher sampling frequency in an up-sampling filter; and, second image data at the said higher sampling frequency is down-sampled in a sampling ratio M:N to the said lower sampling frequency in a down-sampling filter where the combination of the up-sampling filter and the down-sampling filter is substantially transparent and every filtered sample is formed from a weighted sum of at least two input samples.

Abstract: The invention concerns image processing and, in particular, the processing of picture attribute fields for an image. A method of obtaining a new picture attribute field of an image is disclosed in which a picture attribute value at one position is allocated to a new position in the image in dependence upon the value of a parameter, such as luminance data, at the original position and at the new position and/or in dependence on the distance between the original position and the new position. The invention may be used to process picture attribute fields comprising: motion vectors; motion vector confidence; segment labels; depth labels; texture labels.

Abstract: Resampling a spatially sampled attribute of an image, for example up- or down-conversion, in which contributions to a symmetrical FIR resampling filter from positions outside the image—that is to say where the filter aperture extends beyond an image edge—are obtained by copying values from positions inside the image. This can conveniently be done by modifying filter coefficients.

Abstract: A moving image sequence is automatically reframed for a small display. The framing is adjusted in dependence upon foreground and background segment weights derived for pixels in images in the sequence. Reframed images are formed from only those input pixels which fall within a reframing window within the input image area and the position or size of the reframing window is adjusted so as to maximize a weighted total of the sum of the foreground weights of pixels within the window and the sum of the background weights of pixels outside the window.

Abstract: Systems and methods of rendering a motion image. A television signal is modified through a sine wave motion judder component to introduce intentional motion judder which can replicate the appearance of cinematic projection. To present 24 frames per second film via a 60 Hz television system with the “look” of a 72 Hz cinematic projector, a judder oscillator is set to generate a 24 Hz sinewave having a peak amplitude equal to 38.5% of the time difference between 24 Hz frames. The motion-judder component may periodically reverse the apparent direction of motion.

Abstract: An image or other sample processor has a resampling filter adapted to provide output samples at an output sampling frequency which can be selected to be higher or lower than the input sampling frequency. The width of the resampling filter aperture is scaled according to either the input sampling frequency or the output sampling frequency so as to obtain the wider of the two possible filter apertures.

Abstract: The present invention relates to methods and apparatus for interpolation of images, and in a particular example to de-interlacing of video signals using spatial interpolation. The present invention discloses a method for measuring the slope of a picture portion in which picture gradients are calculated from said selected pixel values and the slope measurement being derived from said gradient values. The invention also discloses a method of spatial interpolation of an array of pixel values, in which interpolated values are dependent upon the measurement of the slope associated with said array. Non-integer slopes can easily be accommodated with the method of the invention.

Abstract: A video de-interlacer forms a first new-pixel value from motion compensation of a pixel of a previous field with a first motion vector and forms a second new-pixel value from motion compensation of a pixel of a next field with a second motion vector. These two new-pixel values are then summed with a weighting which depends upon the respective confidence values associated with the two motion vectors.

Abstract: A video process receives an interlaced sequence of input fields organized in a plurality of frames and identifies whether each video cut occurs at a frame boundary. Where a cut occurs otherwise than at a frame boundary, the processes generates a synthetic field by motion compensation and interpolation. This synthetic field replaces one of the fields at the cut, effectively re-timing the cut to a frame boundary. The process thereby outputs a sequence of output fields in which every cut is positioned at a frame boundary, the sequence of output fields containing the same number of fields as the sequence of input fields.

Abstract: This invention concerns the interpolation of new intermediate images within an existing set of related images, for example views of a scene captured at different times, such as a sequence of film frames or video fields, or views of a scene captured from different camera positions, either simultaneously or in a time sequence. Motion vectors established for pixels or regions in at least one existing image are used to shift those pixels or regions to the output position of the new image. The shifted pixels or regions are combined in dependence on a probability of accuracy measure for the respective motion vector. The probability of accuracy measure may be formed from displaced-field difference measurements. The occlusion of objects is determined and used in forming the probability of accuracy measure.

Abstract: For monitoring an image transformation such as aspect ratio conversion, an image feature is defined by identifying a position in the image having a local spatial maximum value and then identifying four other positions in the image having local spatial minimum values such that the four minimum value positions surround the position of the maximum, a first pair of the minimums lie on a first line passing through maximum and a second pair of the minimums lie on a second line passing through the maximum.

Abstract: Systems and methods for detecting a border region in an image. A blank border in a video picture is determined by summing luminance or other pixel measures in a direction parallel to the border and looking for the maximum gradient of those summed measures in a direction perpendicular to the border. Sensitivity can be enhanced by increasing (relative to other pixels) the gain of pixels around the present pixel value of the border. The location of the maximum gradient may be weighted by other measures before a decision on border location is taken.

Abstract: To detect the presence of the left and right constituent images of a stereoscopic image packed within an image frame or within a sequence of image frames, images are unpacked according to each one of said known formats; a candidate measure is formed according to each unpacking and the candidate measures are compared to identify the presence of left and right images packed according to an identified format. The candidate measure may be a low pass filtered measure of the difference between the left and right images and may be a high pass filtered measure of the activity in either the left or the right image.

Abstract: To generate a warning that a stereoscopic image sequence has been synthesised from a 2D image sequence, a video processor correlates left-eye image data and right-eye image data to identify any sustained temporal offset between the left-eye and right-eye image data. A measure of sustained correlation between a measured spatial distribution of horizontal disparity and a spatial model can also be used to generate the warning.

Abstract: A frame-rate conversion system having an interpolation mode and a synchronisation mode. The synchronisation mode is selected when temporal interpolation confidence is and images can be retimed without dropping or repeating of images. The interpolation mode is selected when the measure of temporal interpolation confidence is high or repeating of images. Images are exchanged between a temporal interpolator and a buffer at an exchange rate which is varied in the interpolation mode to optimise the buffer occupancy for retiming of images without dropping or repeating of images in s subsequent synchronisation.

Abstract: A method of composite decoding in which the input signal is converted into the frequency domain, and the symmetry of frequency components with respect to the subcarrier frequency is compared. The comparison is varied in dependence upon the frequency being processed. In this way, the separation can be adapted to suit known characteristics of different portions on the input spectrum. This is particularly useful for processing NTSC signals. The allocation of a particular component to chrominance may be biased in dependence upon a measure of the luminance information of the composite signal at a corresponding spatial frequency.

Abstract: A method of processing in an image processor a pair of images intended for stereoscopic presentation to identify left-eye and right-eye images of the pair. The method includes dividing both images of the pair into a plurality of like image regions, determining for each region a disparity value between the images of the pair to produce a set of disparity values, deriving for each region a confidence factor for the disparity value, determining a correlation parameter between the set of disparity values and a corresponding set of disparity values from a disparity model, in which the contribution of the disparity value for a region to the said correlation parameter is weighted in dependence on the confidence factor for that region, and identifying from said correlation parameter the left-eye and right-eye images of the pair, wherein the left eye and right images form a stereoscopic pair.

Abstract: An adaptive low pass filtering process with a filter delay DA is conducted in parallel with reference low pass filtering process with a filter delay DR which is greater than DA. The error is measured between a delayed version of the adaptive process output and the reference process output. Filter parameters of the adaptive process are controlled to minimise the error.