1. A method of processing an image in an image processor, comprising the steps of receiving input samples representing a spatially sampled attribute of an image; providing a symmetrical resampling filter having a plurality of filter-inputs defining a filter aperture and a filter-output and configured to take contributions from some or all of the filter-inputs to provide the filter-output; and  resampling said samples with said resampling filter to provide output samples, in which the aperture extends beyond an image edge for some output samples; wherein contributions to said resampling filter from positions outside the image are obtained by copying values from positions inside the image and wherein the said positions inside the image and the respective said positions outside the image are equidistant from an image edge.