Wiener Filtering Using Object and Noise Power Spectra for CsI(Tl)-Scintillator Radiography Detectors

The performance of the modulation transfer function (MTF) of indirect detectors, which is based on CsI(Tl) scintillator, is commonly worse than that of the direct detector, which is based on a-Se photoconductor, and can be improved using an image restoration technique. In this paper, the MTF performance of indirect detector were improved from an image restoration technique based on the Wiener filter. We used previously calculated noise power spectrum for the Wiener filter with the signal power spectrum calculated from the input image. Depending on the incident exposure of the acquired image, we could achieve an optimal MTF performance in terms of minimum mean square error.