|Title||Texture and scale in object-based analysis of subdecimeter resolution unmanned aerial vehicle (UAV) imagery|
|Publication Type||Journal Article|
|Year of Publication||2009|
|Authors||Laliberte, Andrea S., Rango A.|
|Journal||IEEE Transactions on Geoscience and Remote Sensing|
|ARIS Log Number||225738|
|Keywords||journal, monitoring, remote sensing, texture, UAV|
Imagery acquired with unmanned aerial vehicles (UAVs) has great potential for incorporation into natural resource monitoring protocols due to their ability to be deployed quickly and repeatedly and to fly at low altitudes. While the imagery may have high spatial resolution, the spectral resolution is low when lightweight, off-the-shelf digital cameras are used, and the inclusion of texture measures can potentially increase the classification accuracy. Texture measures have been used widely in pixel-based image analysis, but their use in an object-based environment has not been well documented. Our objectives were to determine the most suitable texture measures and the optimal image analysis scale for differentiating rangeland vegetation using UAV imagery segmented at multiple scales. A decision tree was used to determine the optimal texture features for each segmentation scale. The error rate of the decision tree was lower, prediction success was higher, class separability was greater, and overall accuracy was higher (high 90% range) at coarser segmentation scales, between 55 and 70 (range 10-80). The inclusion of texture measures increased classification accuracies at nearly all segmentation scales, and entropy was the texture measure with the highest score in most decision trees. The results demonstrate that UAVs are viable platforms for rangeland monitoring and that the drawbacks of low-cost off-the-shelf digital cameras can be overcome by including texture measures and using object-based image analysis highly suitable for very high resolution imagery.