Abstract: To control loudness during a junction between different types of broadcast content, such as a junction between programme and commercial or promotional content, representative loudness values for content respectively before (P) and after (C) the junction are received from a playout automation system. A time-varying gain control is applied before and after the junction in order to smooth loudness around the junction. The audio gain is smoothly increased prior to the junction to a gain (P+C)/2P times higher than the original gain value. Then, the gain is reduced shortly before the junction to a value (P+C)/2C times lower than the original gain value. After the junction, the gain is returned smoothly to the original value.

Abstract: An array of pixel-to-pixel dissimilarity values is analysed to select a pixel which has a low pixel-to-pixel dissimilarity value and which has neighbouring pixels which have a low pixel-to-pixel dissimilarity value. Each pixel-to-pixel dissimilarity value represents a difference between the value of a pixel in a first spatial pixel array representing a first image and the value of a corresponding pixel in a second spatial pixel array representing a second image. The pixels neighbouring the current pixel are divided into at least two polar sectors. The current pixel is selected when the current pixel and the pixels of at least one polar sector have low dissimilarity values.

Abstract: In for example the assignment of motion vectors, an array of pixel-to-pixel dissimilarity values is analyzed to identify a pixel which has a low pixel-to-pixel dissimilarity value and which has neighboring pixels which have a low pixel-to-pixel dissimilarity value. The pixel-to-pixel dissimilarity values are filtered with a filter aperture decomposed into two or more sectors with partial filters applied respectively to each sector. Outputs of the partial filters are combining by a non-linear operation, for example taking the minimum from diametrically opposed sectors.

Abstract: A method of enhancing the perceived sharpness of an image by controlling a spatial interpolation process. A pixel value spatial gradient measure is formed and used to generate a map of modified pixel positions. In this map, the pixel spacing is reduced when the gradient measure is high. By using this map of modified pixel positions to control an otherwise conventional interpolation process, an output image is formed having a perceived sharpness which is greater than that of the unmodified output of the interpolation process.

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: An image manipulation process is controlled by a spatial periodicity measure formed for an image or an image block by measuring the sparseness of the two-dimensional spatial frequency spectrum of the image on a scale of zero to unity in which a two-dimensional spatial frequency spectrum having all equal values has a sparseness of zero and in which a two-dimensional spatial frequency spectrum having only one non-zero value has a sparseness of unity. Sparseness may be measured by allocating values of the spectrum to frequency bins and counting the number of bins that contain non-zero values; comparing values of the spectrum with a threshold and counting the number of values that exceed the threshold; or forming a function of the mean-square value and the mean value of the spectrum values.

Abstract: A motion estimator has a spatial sub-sampler to receive input images; at least one motion estimator determining motion vectors between input images and sub-sampled motion vectors between sub-sampled images; an up-sampler for up-sampling the sub-sampled motion vectors; and a selector for providing a motion vector output by selecting between the motion vectors and the (up-sampled) sub-sampled motion vectors, according to motion vector confidence.

Abstract: To generate a warning that a stereoscopic image sequence has been synthesized 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 method of identifying the left-eye and the right-eye images of a stereoscopic pair, comprising the steps of comparing the images to locate an occluded region visible in only one of the images; detecting image edges; and identifying a right-eye image where image edges are aligned with a left hand edge of an occluded region and identifying a left-eye image where more image edges are aligned with a right hand edge of an occluded region.

Abstract: An image manipulation process is controlled by a spatial periodicity measure formed for an image or an image block by measuring the sparseness of the two-dimensional spatial frequency spectrum of the image on a scale of zero to unity in which a two-dimensional spatial frequency spectrum having all equal values has a sparseness of zero and in which a two-dimensional spatial frequency spectrum having only one non-zero value has a sparseness of unity. Sparseness may be measured by allocating values of the spectrum to frequency bins and counting the number of bins that contain non-zero values; comparing values of the spectrum with a threshold and counting the number of values that exceed the threshold; or forming a function of the mean-square value and the mean value of the spectrum values.

Abstract: An image manipulation process is controlled by a spatial periodicity measure formed for an image or an image block by measuring the sparseness of the two-dimensional spatial frequency spectrum of the image on a scale of zero to unity in which a two-dimensional spatial frequency spectrum having all equal values has a sparseness of zero and in which a two-dimensional spatial frequency spectrum having only one non-zero value has a sparseness of unity. Sparseness may be measured by allocating values of the spectrum to frequency bins and counting the number of bins that contain non-zero values; comparing values of the spectrum with a threshold and counting the number of values that exceed the threshold; or forming a function of the mean-square value and the mean value of the spectrum values.

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 minimize the error.

Abstract: A method of enhancing the perceived sharpness of an image by controlling a spatial interpolation process. A pixel value spatial gradient measure is formed and used to generate a map of modified pixel positions. In this map, the pixel spacing is reduced when the gradient measure is high. By using this map of modified pixel positions to control an otherwise conventional interpolation process, an output image is formed having a perceived sharpness which is greater than that of the unmodified output of the interpolation process.

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: A video process is controlled through a one-dimensional control function to affect the two outcomes of processing cost and processing error. Points are generated in error/cost space corresponding to multiple combinations of parameter values applied to the process using reference input data. A subset of points is selecting in which each point is such that all other points in the space have either a higher error or a higher cost, to define the one-dimensional control function.

Abstract: In video motion estimation an initial candidate motion vector is generated for each block and a vector error is determined as for example a DFD. Spatial gradients of pixel values are calculated and used to refine the initial candidate motion vector. The relative contribution of the spatial gradients to the refinement process depends on the vector error.

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: Apparatus for interpolating images generates motion vectors having a vector confidence value and has a motion compensated interpolation to use the motion vectors to interpolate a new image from two input images at a position determined by a phase control signal. The vector confidence values are used to generate an interpolation confidence measure. The phase control signal is then modified to offset the position at which the new image is interpolated toward the position of the closer of the two input images, if said interpolation confidence measure reduces.

Abstract: A method of analysing an array of pixel-to-pixel dissimilarity values to identify a pixel which has a low pixel-to-pixel dissimilarity value and which has neighbouring pixels which have a low pixel-to-pixel dissimilarity value; the method comprising filtering the pixel-to-pixel dissimilarity values and varying the spatial extent of the filter aperture in dependence upon a picture spatial activity measure.

Abstract: To detect non-uniform spatial scaling of an image in the horizontal direction (for example in 4:3 to 16:9 aspect ratio conversion) the image is divided into regions, for example a middle region and two side regions. A measure of horizontal spatial frequency energy is taken in each region by for example subtracting the values of horizontally adjacent pixels and a comparison is made between measures of horizontal spatial frequency energy for the different regions.