Skip to main content
. Author manuscript; available in PMC: 2011 Apr 13.
Published in final edited form as: Opt Express. 2010 Aug 30;18(18):18598–18614. doi: 10.1364/OE.18.018598

Fig. 5.

Fig. 5

The Wiener-filtered phase retrieval transfer function (wPRTF) provides a good measure of reconstructed image quality over a wide range of photon exposures. Shown at right are a series of wPRTF curves for reconstructions of simulated data with several different photons per pixel values and simulated Poisson noise. The spatial frequency at which the wPRTF crosses the dashed 0.5 line is taken as effective resolution for each data set. On left, a power law fit to the power spectral density (PSD) of the data set with the highest photons per pixel value (black) is compared to a power law fit to the dose–resolution data (red) derived from the figure on the right. The magnitudes of both slopes agree within their error, indicating that the degree to which scattering decreases with spatial frequency in an object is equal to the degree at which reconstructed image resolution falls off with decreasing exposure [1].