Sky-canopy border length, exposure and thresholding influence accuracy of hemispherical photography for complex plant canopies.

ABSTRACT:

Background

Hemispherical photography (HP) is a popular method to estimate canopy structure and understorey light environment, which analyses photographs acquired with wide view-angle lens (i.e. fisheye lens). To increase HP accuracy, the approaches of most previous studies were to increase the preciseness of exposure and thresholding of photographs, while ours quantified effects of canopy properties (gap fraction and length of sky-canopy border (SCB)) and errors of exposure and thresholding on the accuracy of HP.

Results

Through analysing photographs of real and model canopies, it was showed that HP inaccuracy resulted from the mismatch between exposure and thresholding rather than exposure or thresholding errors alone. HP inaccuracy was a function of the SCB length and the

SUBMITTER: Song GM 

PROVIDER: S-EPMC6064577 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature