Fig. 2
From: High-resolution X-ray phase-contrast tomography of human placenta with different wavefront markers
Modulator reference maps, visibility analysis and stepping patterns for the two wavefront markers. (a) Reference image details from the centre of the FOV of the \({7}\,\upmu \hbox {m}\) period TAI and (d) the \({6 \times 1000}\) grit sandpaper, with zoomed insets of the highlighted region. (b,e) Show the visibility maps and the insets show the speckle pattern 2D auto-correlation map (\({20 \times 20}\) pixel around the peak—dark red, base—blue). The insets aid in the visualisation of the mean size of the marking structures (\(\textrm{FWHM}_{\textrm{TAI}}\) = 2.85 pixel vs. \(\textrm{FWHM}_{\textrm{6x1000}}\) = 5.82 pixel). The estimated mean visibilities for the TAI and sandpaper are 15.0% and 22.5%, respectively. The modulator stepping patterns for the two acquisitions are shown in (c,f).
