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 method of video or audio processing receives a sequence of sample values, each corresponding with a location in video or audio content; forms an initially estimated quantile value; and then modifies the estimated value in dependence upon a count of the results of comparisons between sample values within a fixed-length interval of the sequence of samples values and the estimated value to form an estimated quantile of the sequence of sample values.

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: In the creation of video program material, picture composition decisions—especially framing parameters—taken by an operator for small-display presentation of a scene are used the automatic generation of picture composition decisions for a larger display. Framing parameters such as pan, are temporally filtered before being applied to the wider field of view provided for the larger display.

Abstract: In for example the assignment of motion vectors, an array of pixel-to-pixel dissimilarity values is analysed 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 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: To assess picture impairment due to the interpolation of output images from input images, for example in standards conversion, an output image detail measure is compared with an input image detail measure. One of the image detail measures is obtained by interpolation between image detail measures for at least two images.

Abstract: To modify the aspect ratio of images in a video sequence, a measure of image energy is provided at or around each pixel, for example by taking differences between adjacent pixels. A minimum energy path of contiguous pixels is then identified which extends across the image from one edge to another, for example vertically if the width of the picture is to be modified. Information concerning the location of a path in one image is used in the identification of a path in the next image, for example by biasing the energy measure of the path. The aspect ratio of each image is then modified by removing or by replicating the minimum energy path of contiguous pixels.

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: 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: 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: 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 method of compressing data representing a sequence of images in dependence upon data defining at least one region of particular interest within at least one image in the sequence includes causing data representing an image region that is not of particular interest to be more highly compressed than data representing an image regions that is of particular interest.

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.

Abstract: This invention concerns the spatial interpolation of color images and, in particular, the reconstruction, or “de-mosaicing” of data from a single sensor-array electronic camera. Electronic cameras typically have an image sensor comprising a matrix of individual pixel sensors, each sensor being responsive to a color component. In order to obtain color component information for all pixels, in accordance with the disclosed embodiment, green component pixel values (203) are interpolated to obtain green component pixel values for all pixels (209). A difference value (B?G) (212) is formed from the green color component values (207) and the original blue component values (204) at blue pixel locations, and the difference values (B?G) (212) are then interpolated to obtain difference values for all pixels (216). Blue component values for all pixels (225) can then be obtained from the difference values for all pixels (216) and the green component values for all pixels (209).

Abstract: In the creation of video program material, picture composition decisions—especially framing parameters—taken by an operator for small-display presentation of a scene are used the automatic generation of picture composition decisions for a larger display. Framing parameters such as pan, are temporally filtered before being applied to the wider field of view provided for the larger display.

Abstract: In the creation of video program material, picture composition decisions—especially framing parameters—taken by an operator for small-display presentation of a scene are used the automatic generation of picture composition decisions for a larger display. Framing parameters such as pan, are temporally filtered before being applied to the wider field of view provided for the larger display.