Vallmitjana i Rico, SantiagoJuvells Prades, IgnacioCarnicer González, ArturoCampos Coloma, Juan2020-09-222020-09-2219910277-786Xhttps://hdl.handle.net/2445/170719A simple method for optical implementation of a composite filter in a joint transform correlator is presented. A composite filter in object space is a real function, but by adding an appropriate constant value, only positive values are obtained. As a drawback, the bias introduced decreases the relative height of the correlation peaks in the recognition process. Non-linear effects in a joint transform correlator are used to increase discrimination by using positive composite filters. Digital simulation and optical implementation of the process has been carried out, achieving the non-linearities by means of saturation effects on the intensity detection process.9 p.application/pdfeng(c) Society of Photo-Optical Instrumentation Engineers (SPIE), 1991Reconeixement òptic de formesÒptica de FourierOptical pattern recognitionFourier opticsinfo:eu-repo/semantics/article0639142020-09-22info:eu-repo/semantics/openAccess