The concepts of impulse response and transfer function which are so basic to electronic engineering are summarized with regard to imaging systems. Analogies between optical and electronic transfer functions are developed. In electronic systems the signals are time-dependent and the Fourier frequencies are in units reciprocal to time. In imaging systems the information is the spatial dependence of light intensity. Concequently, in Fourier optics the frequencies are in units reciprocal to spatial dimension, such as cycles per millimeter. Modulation Contrast Function (MCF) is defined and, for sin wave objects, shown to be equal to the amplitude of the optical transfer function (modulation transfer function, or MTF). This association of contrast with MTF is used to derive imaging system resolution in terms of spatial frequency content.
|State||Published - 1 Dec 1985|