Influence of image source, resolution, and segmentation method on the estimation of gap fraction
Loading...
Date
2023-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of New Brunswick
Abstract
Gap fraction is a critical measure in forestry, providing information about the structure and dynamics of forest ecosystems. In recent years, the use of digital cameras to measure gap fraction has become increasingly popular, because they offer a quick and efficient way to gather structural data that is difficult to directly measure in the field. However, costs and qualities of cameras vary widely, and it is unclear how these differences affect gap fraction estimates. This study compares gap fraction estimates obtained from an inexpensive spherical camera (Ricoh Theta Z1) to a more expensive industrial standard camera (Sony α NEX-7) and assesses effects of image resolution and segmentation method on comparability. Our results showed good correspondence between the two cameras when using high resolution reprojections of Ricoh spherical images and Otsu thresholding for segmentation. In addition, the Ricoh camera does not require gyroscopic mounts to assure vertical camera alignment.