A New Technique for Estimating the Modulation Transfer Function of an Imaging System from Its Edge Response

摘要

The optical transfer function (OTF) is the name given to the two-dimensional Fourier transform of an imaging system's impulse response or point spread function, where a point source in the field of view is an impulse. The modulation transfer function (MTF) is the modulus of OTF. A cross section of the MTF can be estimated from a noisy knife-edge image recorded in the film. An MTF estimate is useful for system performance analysis (if the film effects are backed out) and image enhancement. The new method for estimating the MTF proposed in this report has two major advantages over other methods reported in the literature: the averaging effects of the microdensitometer aperture and the nonlinear film characteristics can be included in the regression equation, and the phase errors between successive edge scans are estimated. (Author)