Evaluation of the Wiener Spectrum of Radiographic Screen-Film Systems by Entropy

Abstract

The Wiener spectra of radiographic screen-film systems are assessed by the entropy method, which is considered to be a method of evaluation based on the precision of measurements. The spectral resolution associated with the fluctuation and gradient of the measured spectra can be calculated by this method. The relative spectral resolution of the Wiener spectrum is defined by the relative efficiency of transmission. Using the results of entropy calculations, the Wiener spectra of three screen-film systems are evaluated by comparing the values of the transmitted information or the relative spectral resolution of each system. It is concluded that a screen-film system should be evaluated by both the Wiener spectrum, related to the accuracy, and the entropy, related to the precision.