Improving the normalized difference built-up index to map urban built-up areas using a semiautomatic segmentation approach
CHUNYANG HE1,2,*, PEIJUN SHI1, DINGYONG XIE2 and
YUANYUAN ZHAO1,2
1 State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China
2 College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China
Abstract
Remote sensing images are useful for monitoring the spatial distribution and growth of urban built-up areas because they can provide timely and synoptic views of urban land cover. Although the normalized difference built-up index (NDBI) is useful to map urban built-up areas, it still has some limitations. This study sought to improve the NDBI by using a semiautomatic segmentation approach. The proposed approach had more than 20% higher overall accuracy than the original method when both were implemented simultaneously at the National Olympic Park (NOP), Beijing, China. One reason for the improvement is that the proposed NDBI approach separates urban areas from barren and bare land to some extent. More importantly, the proposed method eliminates the original assumption that a positive NDBI value should indicate built-up areas and a positive normalized difference vegetation index (NDVI) value should indicate vegetation. The new method has improved universality and lower commission error compared with the original method.
*Corresponding author. Email: hcy@bnu.edu.cn
Published in Remote Sensing Letters, Vol. 1, No. 4, December 2010, 213–221
(Received 20 December 2009; in final form 26 March 2010)
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| Comparison of the results by the original and proposed approaches |
