The measurement of phase distortion due to filtering in digital pictures

This paper introduces a measure of phase distortion due to filtering in digital pictures. Given the amplitude spectrum of an input picture and the desired and actual frequency responses of a digital filter, the measure may be calculated. When the measure is applied to output pictures of a filter, the acceptability of the phase response of the filter may be judged. When the amplitude response of the input picture is modeled by a simple function, an estimate of the measure may be calculated with greatly reduced storage requirements and computation time. Examples illustrating the results are included.