Abstract: Image processing apparatus comprises a demosaic processor for receiving a video signal comprising pixel data from an array of photosensors each having a respective color filter so as to restrict the sensitivity of that photosensor to a primary color range selected from a set of three or more primary color ranges, the array being such that the photosensors in alternate rows are sensitive to a first primary color range, and photosensors in intervening rows are sensitive to the other primary color ranges. The pixel data including pixel data from a first subset of the rows sensitive to the first primary color range, the first subset being the same from image to image of the video signal; and pixel data from a second subset of the rows of photosensors sensitive to the other primary color ranges, the second subset changing from image to image of the video signal.

Abstract: A method of pixel interpolation in which a two-dimensional digital filter is arranged so as to interpolate an output pixel from a two-dimensional array of color input pixels by aligning a filtering operation with a detected direction of an image feature at a pixel position to be interpolated comprises detecting image activity within respective color components of a group of input pixels around the pixel position to be interpolated; generating monochromatic test pixels by combining the color components of input pixels in relative proportions dependent upon the detected image activities; detecting the direction of an image feature in a group of the monochromatic test pixels around the pixel position to be interpolated; and interpolating an output pixel using the two-dimensional filter, according to the detected image feature direction.

Abstract: A method of pixel interpolation in which a two-dimensional digital filter is arranged so as to interpolate an output pixel from a two-dimensional array of input pixels comprises detecting the direction of an image feature at a pixel position to be interpolated; applying a shear transformation to the digital filter and/or to the array of input pixels so as to map the operation of the filter to the detected image feature direction in respect of at least a first one of two axes of the two dimensional filter; and applying the digital filter to obtain the output pixels.

Abstract: A method of data processing. The method comprises applying a filter to an input sample set comprising sample values selected from an input sequence of input sample values, so as to generate a corresponding output sample value having an output sample value position with respect to the input sample set, in which the filter has a maximum output range. The method further comprises deriving a permissible output value range from an input group of two or more input sample values in the input sample set which surround the output sample value position, detecting whether the output of the filter is outside the permissible output value range and, if so, limiting the output of the filter to lie within the permissible output value range.

Abstract: Image processing apparatus comprises a demosaic processor for receiving a video signal comprising pixel data from an array of photosensors each having a respective color filter so as to restrict the sensitivity of that photosensor to a primary color range selected from a set of three or more primary color ranges, the array being such that the photosensors in alternate rows are sensitive to a first primary color range, and photosensors in intervening rows are sensitive to the other primary color ranges. The pixel data including pixel data from a first subset of the rows sensitive to the first primary color range, the first subset being the same from image to image of the video signal; and pixel data from a second subset of the rows of photosensors sensitive to the other primary color ranges, the second subset changing from image to image of the video signal.

Abstract: A method of pixel interpolation in which a two-dimensional digital filter is arranged so as to interpolate an output pixel from a two-dimensional array of colour input pixels by aligning a filtering operation with a detected direction of an image feature at a pixel position to be interpolated comprises detecting image activity within respective colour components of a group of input pixels around the pixel position to be interpolated; generating monochromatic test pixels by combining the colour components of input pixels in relative proportions dependent upon the detected image activities; detecting the direction of an image feature in a group of the monochromatic test pixels around the pixel position to be interpolated; and interpolating an output pixel using the two-dimensional filter, according to the detected image feature direction.

Abstract: A method of pixel interpolation in which a two-dimensional digital filter is arranged so as to interpolate an output pixel from a two-dimensional array of input pixels comprises detecting the direction of an image feature at a pixel position to be interpolated; applying a shear transformation to the digital filter and/or to the array of input pixels so as to map the operation of the filter to the detected image feature direction in respect of at least a first one of two axes of the two dimensional filter; and applying the digital filter to obtain the output pixels.

Abstract: A method of data processing. The method comprises applying a filter to an input sample set comprising sample values selected from an input sequence of input sample values, so as to generate a corresponding output sample value having an output sample value position with respect to the input sample set, in which the filter has a maximum output range. The method further comprises deriving a permissible output value range from an input group of two or more input sample values in the input sample set which surround the output sample value position, detecting whether the output of the filter is outside the permissible output value range and, if so, limiting the output of the filter to lie within the permissible output value range.