STUDY OF THE MODULATION TRANSFER-FUNCTION USING SPECKLE PHOTOGRAPHY

A quadratic model of a truncated parabolic-wave object is proposed to represent a periodic test object. This test object is experimentally c onstructed using a multi-exposure specklegram which forms a pattern ne arly equivalent to the model described. The imaging irradiance distrib ution is calculated from the convolution product of the object irradia nce and the impulse response of the incoherent imaging system. The the oretical results of the imaging irradiance and the corresponding contr ast of the imaging systemm are graphically represented. The theoretica l curve of the contrast or modulation transfer function (MTF) showed a n agreement with the experimental one obtained from the interference p atterns of the modulated speckle.