may be arranged by means of the pixel address generator 58 which controls the scanning of the stores and the address offset selector 59 to be displaced by one or more pixel positions horizontally and or vertically from the addressing of store 32b these offsets are typically specified for the duration of each of a number of successive frames in parallel with the multiplying coefficient thus the image in 32a becomes a modified version of that in 32b the modification being the addition of weighted values of nearby pixels to each pixel in the original the coefficients and offsets can for example be chosen to improve edge sharpness fig7 shows a typical combination of weighting functions and address offsets for the modification of each pixel by a 3 u00d7 3 matrix of its nearest neighbours such an arrangement is relatively fast in operation a 3 u00d7 3 matrix will take 9 frames to process this is much faster typically 50 times than would be achieved using software processing techniques the multiplier 55 could be part of an arithmetic processor so that a very versatile arrangement is provided an alternative arrangement to fig6 is to replace multiplier 55 by a binary shifter controlled from a list.