1. A method for detecting edges in an image using an image sensor that comprises a two-dimensional array of addressable pixels, with each of said pixels providing a data value indicative of a portion of the image sensed by that pixel, the method comprising the steps of: (a) sensing the image using the image sensor; and (b) carrying out the following steps for each of a number of selected pixels using a localized group of pixels surrounding each selected pixel: (b1) accessing a one-dimensional set of pixels contained within the localized group of pixels; (b2) reading the data values associated with the pixels accessed in step (b1); (b3) determining an intermediate data value using a smoothing function that is applied to the data values read in step (b2); (b4) repeating steps (b1) through (b3) for each of the one-dimensional sets of pixels contained within the localized group to thereby produce a set of said intermediate data values; and (b5) determining a final data value for the selected pixel using a differencing function that is applied to the set of intermediate data values.