Canadian Forest Service Publications

Tree crown (ITC) delineation on Ikonos and QuickBird imagery: the Cockburn Island study. 2003. Gougeon, F.A.; Cormier, R.; Labrecque, P.; Cole, B.; Pitt, D.G.; Leckie, D.G. Page in Proceedings of the 25th Canadian Symposium on Remote Sensing (CDROM), Proceedings: 25th Canadian Symposium on Remote Sensing. October 14-17, 2003, Montreal, Quebec. Canadian Remote Sensing Society, Ottawa, ON.

Year: 2003

Issued by: Pacific Forestry Centre

Catalog ID: 25313

Language: English

Availability: PDF (download)

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For forestry applications with high spatial resolution (< 1 m/pixel) imagery, an Individual Tree Crown (ITC) approach is generally preferable to pixel-based analyses. This paper presents preliminary results of ITC delineations using a valley following approach over Cockburn Island (Lake Huron, Ontario), first with an Ikonos image (100 cm/pixel), then with a QuickBird image (70 cm/pixel), to examine some of the benefits of the added spatial resolution. Six test areas, typically containing only one situation (i.e., big or small trees, deciduous or coniferous), were analysed on both images. For reference, local maxima (or Tree Top) analyses were also performed and are shown for both media. As expected, the results favour QuickBird with gains in areas of trees with narrow crown (less omission errors), better separation of tree clusters and finer delineation of crown boundaries. In general, the QuickBird image analysis produced 50% more tree crowns and is in closer agreement with its Tree Top counts. From visual inspection, it is obvious that a significant number of tree clusters remain.

This work is part of a larger “proof of concept” project, done in collaboration with forestry and forest inventory companies, that intends to check if an ITC approach can lead to better forest management maps. The project will evaluate the automatic creation of forest stand polygons, their species composition (up to 10 species) and parameters such as stem density and crown closure, as well as, the synergistic effects of using a large scale photography (LSP) sampling strategy for volume estimation.