基于小波变换的影像融合在动态监测中的应用

基于小波变换的遥感影像融合是一种重要的图像信息增强方法，提出了将其应用于土地利用遥感动态监测，以自动探测土地利用发生变化的区域。方法是将某时相的多光谱影像进行主成分变换，用其第一主成分与另一时相的多光谱影像进行数据融合，融合规则是对两时相影像的小波系数进行加权平均法计算。经室内资料检核和野外验证发现，得到的变化信息的噪声小图斑较少，结果精度能满足实际应用需要。

Dynamic Monitoring Using Image Fusion by Wavelet Transform

Remote sensing images are primary data source for dynamic monitoring in land using,at the same time, DEM, relief map, land using detail survey map and other literal information are used as assistant tools in monitoring. There are many kinds of automatically detecting methods applied to detect changing information in land using, including post-classification comparison method and pixel to pixel comparison method, and image fusion method is belong to the latter. Remote sensing image fused by wavelet transform, which is an important image information enhancing method, can be used to detect land using changing patches automatically. After principle and advantages of two dimension wavelet transform theory have been introduced, an idea applying the theory in remote sensing dynamic monitoring in land using to automatically detect land using changing patches is presented. After utilizing principal component transform on a temporal multi-spectrum image, the first principal component is fused with another temporal multi-spectrum image by computing the tow temporal images' wavelet coefficient using weighted mean value, and cubic spline wavelet function is used to transform image to wavelet coefficient. When the three bands which are formed by multi-spectrum image fusion are used in false color displaying, there will be spectrum characteristic changes in areas where land using is changing and the areas are losing spectrum harmony with around objects, so, the changing patches can be detected automatically. Proved by checking indoor information and field validating, the precision can meet practical application demand for the detected changing information with low noise.