An Analysis Method of Measurement of Noise Spectrum in the Ultra Low Space Frequencies of a Radiographic Film by MEM

Abstract

The noise power spectra of radiographic film have been used to analyze the graininess of radiography. Furthermore, it has recently become clear that graininess analysis, especially at low space frequencies, is needed for quantitative evaluation of a radiographic screen/film system. This paper describes a method for analysis of film at low space frequencies that is based on the maximum entropy method (MEM). This method can determine the basic order of MEM to maximize the ratio of the order to the power spectrum at low space frequencies. Experimental results confirmed that the noise power to express the radiographic influence on films can be precisely measured at ultralow space frequencies.