Fig. 7

Edge protrusion of the upstream and downstream edge under different flow conditions 1.5 Pa and 10 Pa. a Protrusion of the downstream and b upstream leading edge at 1.5 Pa and c downstream and d upstream leading edge at 10 Pa using conservative Canny method (orange), as well as iCD (dark blue), iDSD (blue) and freehand (green) e Relative errors plotted as boxplot diagram compiled from a-d. The median is plotted as a vertical line in the box The upper box bound corresponds to the median of the upper half of the data and so also for the lower part. The mean is shown as a cross. The length of the whisker corresponds to 1.5 times the distance between the lower and upper box boundary; outside this range, the data are marked as outliers (circle)