This paper concerns the problem of tree height measurement based on image processing embedded in smart mobile phone. A smart phone with camera and a benching marking were used to in our method. Before the tree photo was taken, a benching marking with red colored ends was leaned on the tree closely and parallel to tree trunk. Then the top point of the tree image was extracted according to their color features. And the coordinates of the two marker points on the end of the benching marking were got too. Lastly, the tree height can be worked out using triangle similarity theory. The experimental results show that the relative measurement error of tree height is about 5%. So it is a viable method.
Keywords-image processing; image segmentation; tree height measurement; smart mobilephoneI.
Moving cast shadows of moving objects significantly degrade the performance of many high-level computer vision applications such as object tracking, object classification, behavior recognition and scene interpretation. Because they possess similar motion characteristics with their objects, moving cast shadow detection is still challenging. In this paper, we present a novel moving cast-shadow detection framework based on the extreme learning machine (ELM) to efficiently distinguish shadow points from the foreground object. First, according to the physical model of shadows, pixel-level features of different channels in different color spaces and region-level features derived from the spatial correlation of neighboring pixels are extracted from the foreground. Second, an ELM-based classification model is developed by labelled shadow and un-shadow points, which is able to rapidly distinguish the points in the new input whether they belong to shadows or not. Finally, to guarantee the integrity of shadows and objects for further image processing, a simple post-processing procedure is designed to refine the results, which also drastically improves the accuracy of moving shadow detection. Extensive experiments on two publicly common datasets including 13 different scenes demonstrate that the performance of the proposed framework is superior to representative state-of-the-art methods.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.