Scatter plots of perimeter length l_pore vs. area A_pore for single (left) and time-averaged (right) G-band images, which also include the respective frequency distributions. Red symbols “×” mark isolated pores. The lower envelope (solid) of the scatter plots refers to perfectly circular pores (α = 1 in Eqn. 1), while the upper envelope (solid) is given by a scaling factor of α = 2.5. Non-linear least squares fits (dashed) using Eq. (1) lead to scaling factors of α = 1.43 and 1.37 for single and time-averaged G-band images, respectively. Median, mean, and 10th percentile of the frequency distributions (light gray bars) are given by solid, dashed, and dash-dotted lines, respectively. Quantitative values of the measures are specified in the panels for perimeter lengths l_pore and areas A_pore. Log-normal frequency distributions (solid) properly fit the histograms.