Tree crown detection in high resolution optical images during the early growth stages of Eucalyptus plantations in Brazil

Abstract

Individual tree detection methods are more and more present, and improve, in forestry and silviculture domains with the increasing availability of satellite metric imagery [2–7]. Automatic detection on these very high spatial resolution images aims to determine the tree positions and crown sizes. In this paper, we use a mathematical model based on marked point processes, which showed advantages w.r.t. several individual tree detection algorithms for plantations [2], to analyze an Eucalyptus plantation in Brazil, with 2 optical images acquired by the WorldView-2 satellite. A tentative detection simultaneously with 2 images of different dates (multi-date) has been tested for the first time, which estimates individual tree crown variation during these dates. While, for most current detection methods, only the static state of tree crowns at the moment of one image's acquisition is estimated. The relevance of detection is discussed considering the detection performance in tree localizations and crown sizes. Then, tree crown growth are deduced from detection results and compared with the expected dynamics of corresponding populations.