CORRELATION FILTER WITH A NOISE ADAPTIVE DISCRIMINANT CAPABILITY

The classical matched spatial filter is optimum for noise but has a po or discrimination capability as it generates very broad output correla tion peaks; whereas, the phase only filter gives excellent discriminat ion via very sharp output correlation peaks, however, it is extremely sensitive to noise. A new adaptive filter is formulated which integrat es the phase only filter with the matched spatial filter. A variable a mplitude threshold value is set so that, at a particular spatial pixel location, if the amplitude value is greater than the pre-set threshol d, only phase information is recorded, otherwise, both the phase and a mplitude information are encoded. When reference images are encoded in to the hybrid correlation system the amplitude threshold value is adju sted by an integrated adaptive controller to optimise noise resistance whilst maintaining discriminant ability. Results show that the new fi lter delivers better overall performance than either the phase only fi ller or matched spatial filter.