基于局部端元提取的遥感影像波段模拟

A Technique for Generating Natural Color Images Based on Local Endmembers

针对"波谱库-影像"多光谱遥感影像波段模拟方法中波谱库以矿物质类别为主、忽略大气环境和成像时间对地物波谱影响的问题,以及"参考影像-影像"影像波段模拟方法中地物混合像元和不同空间分辨率像元间模拟的尺度效应问题,提出基于局部地物端元提取的遥感影像波段模拟方法。首先对与待模拟影像具有相似地物类别组成的参考影像进行光谱聚类分割,形成影像局部区域;然后提取各个局部区域的地物端元,并对地物端元进行优选形成地物端元样本集;接着利用端元样本集建立地物端元波谱间的关系模型;最后利用关系模型预测目标影像波段。首先通过模拟LandsatTM5影像的蓝光波段,验证方法的稳定性和可靠性;然后通过模拟IRS-P6影像的蓝光波段,验证方法的适用性和推广性;并在实验过程中同已有的"波谱库-影像"波段模拟方法和"参考影像-影像"波段模拟方法进行视觉效果对比和定量统计分析,进一步表明方法对各类地物均有较好的模拟效果,能够准确地表达地物的真实波谱。

A method for generating natural color composite of satellite images based on local endmembers of ground features was proposed. First, the reference satellite image which has similar land cover types with the target satellite image is segmented into multiple local patches. Secondly, endmembers of ground features are extracted from each local patch, then we choose better end- members and gather them into a sample set. Thirdly, we use the sample set to build up the relationship between the spectral val- ues of the blue band and the other bands. Finally, the spectrum relationship is used to generate natural color composite of the target image. The verification experiment on Landsat TM5 images shows that the proposed method is reliable and stable to gen- erate the natural color composite of images. The other experiment on IRS-P6 images shows that our method is able to promote for other satellite images. In experiments, we also compared the existing ＂ reference lmage-xmage method and spectral hbrary- image＂ method qualitatively and quantifieationally, indicating that our method is more precise to simulate spectrums of all kinds of ground features.