Fig. 8From: Sky-canopy border length, exposure and thresholding influence accuracy of hemispherical photography for complex plant canopiesa–c Frequency distribution of pixel fraction along the greyness gradient of real CHPs, and d–f estimated gap fraction under different ETM extents. The figure is derived from CHPs of three real canopies with similar gap fraction (0.29, 0.30 and 0.27), with proportion pixel of mixed-pixel zone (i.e. mixed-pixel zone length) of 0.94, 0.37 and 0.24, respectively. Note log scale used on y-axis in panels a–c. The unit of the exposure manipulation, thresholding manipulation and ETM extent is stopBack to article page