The classical matched spatial filter is optimum for noise but has a poor discrimination capability as it generates very broad output correlation peaks; whereas, the phase only filter gives excellent discrimination via very sharp output correlation peaks, however, it is extremely sensitive to noise. A new adaptive filter is formulated which integrates the phase only filter with the matched spatial filter. A variable amplitude threshold value is set so that, at a particular spatial pixel location, if the amplitude value is greater than the pre-set threshold, only phase information is recorded, otherwise, both the phase and amplitude information are encoded. When reference images are encoded into the hybrid correlation system the amplitude threshold value is adjusted by an integrated adaptive controller to optimise noise resistance whilst maintaining discriminant ability. Results show that the new filter delivers better overall performance than either the phase only filler or matched spatial filter. [References: 7]
展开▼
