Image M.T.F. analysis using grain noise
Martin Gouch, Malcolm Roe · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1993
The M.T.F. of an image capture system is a good measure of a system's ability to reproduce sharp pictures. Post image capture processing will enhance the sharpness of the picture but the amount and type of processing required to produce a sharp picture is affected strongly the the M.T.F. of the image capture system. A simple and cheap method for measuring the M.T.F. in these circumstances is to measure the response of the imaging system to low modulation white noise. One such source of low modulation white noise is grain noise present in photographic transparencies. If the grain noise is captured with the image capture system and then Fourier transformed a M.T.F. response is produced. Presented is a practical example of this technique, from obtaining the test targets to producing the M.T.F. graphs. Also presented are some of the pitfalls that can be encountered using the technique.