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Multiinput schemeResponses

In a multiinput scheme similar to two-input one shown on the previous page, stimulation of one input xi evokes a response of the same sign at the appropriate output zi with small responses of the opposite sign at the other outputs. Simultaneous stimulation of all inputs except xi influences mainly the output zi state while the voltages on appropriate outputs change insignificantly. Steady-state values of output voltages are (with the assumption that the gain of the op amp is infinitely large):

zi=1/2*(xi-x), where x=1/N*sum(xi)
This means that a physical model of color constancy with a feedback mechanism can be made on the basis of an operational amplifier.