Fast and accurate extraction of urban ground objects can ensure timely urban environmental monitoring. However, the current technology used to extract urban ground objects has many steps, slow speed and low practicality. In view of the shortcomings of current research, this study takes WorldView-2 as an example, collects typical image categories of urban imagery, conducts spectral curve fitting and characteristic analysis, uses a combination of the addition, subtraction and multiplication operations in some key bands to enhance the information of the target objects and constructs some spectral indices that are beneficial to the extraction of urban red, white, blue and cyan ground objects using the threshold method. The newly created spectral indices can effectively extract four colours of urban ground objects. Among them, the red and blue ground objects have good extraction results, whereas the white and cyan ground objects have poor extraction results. Results show that the new spectral index threshold method can rapidly extract the target ground objects in urban images by colour, which has good practicability.

中文翻译：

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基于新创建的 WorldView-2 多色光谱索引的四类城市地物提取

快速准确地提取城市地物，保证城市环境监测的及时性。然而，目前用于提取城市地物的技术步骤多、速度慢、实用性低。针对当前研究的不足，本研究以WorldView-2为例，收集城市影像的典型影像类别，进行光谱曲线拟合和特征分析，在一些关键波段采用加减乘法相结合的运算。增强目标对象的信息，构建一些有利于利用阈值法提取城市红、白、蓝、青地物的光谱指标。新创建的光谱指数可以有效地提取城市地物的四种颜色。他们之中，红色和蓝色地物提取效果较好，而白色和青色地物提取效果较差。结果表明，新的光谱指标阈值方法可以通过颜色快速提取城市图像中的目标地物，具有良好的实用性。