Hybrid multiplexing matched spatial filters in the Fourier plane for multiple object recognition

An optical-digital approach to fabricating matched spatial filters for multiple image recognition is discussed. Multiplexing is accomplished in the Fourier plane following optical transformation. A screening filter is formed digitally by adding or subtracting the intensity spectra of the transformed images to be recognized or ignored. This screening filter is then used to construct optically a composite image which contains the essential features of the various images to be recognized and from which compromising features have been deleted. The composite image is then used to record the desired filter. Initial results for both recognition and discrimination are presented.