Comparison of Coherent and Incoherent Optical Spectrum Analysis Techniques in Image Evaluation

The application of communication theory and linear systems concepts to the analysis of photographic images and imaging systems is well established. These techniques include the use of the Wiener spectrum to characterize photographic granularity and to determine the transfer functions for photographic imaging and printing; the standard methods of measurement that have been developed use essentially incoherent optical techniques. Recently, however, coherent optical processors have been applied to image analysis. A series of experiments is described which allows comparison of the spectra and the transfer functions generated by the incoherent and the coherent techniques.