实验五 使用ENVI进行TM和SPOT数据融合.docx

实验五 使用ENVI进行TM和SPOT数据融合实验五 使用ENVI进行TM和SPOT数据融合 实验目的：理解数据融合的基本原理，数据融合的过程，掌握ENVI环境下数据融合的方法。 实验内容： 1手动数据融合 2自动数据融合 实验准备： 数据：文件夹lontmsp 英国伦敦的TM 和 SPOT 数据 File lon_spot lon_spot.ers lon_tm lon_tm.ers copyright.txt Description London SPOT data ER Mapper Header for above file London Landsat TM data ER Mapper Header for above file Data copyright statement 实验步骤： To perform data fusion using ENVI, the files must either be georeferenced (in which case spatial resampling is performed on the fly), or if not georeferenced, cover the same geographic area, have the same pixel size, the same image size, and the same orientation. The files used in this exercise are not georeferenced, therefore the low resolution images must be resampled to have the same pixel size as the high spatial resolution image (using nearest neighbor resampling). 一、读取并显示ERMapper影像 The London data are TM and SPOT data binary files with ERMapper header files, and can be automatically read using ENVIs ERMapper reading routines. 1.Select File Open External File IP Software ER Mapper, navigate to the lontmsp subdirectory and select the file lon_tm.ers. 2.Click on the RGB Color radio button in the Available Bands List, click sequentially on the Red Layer, Green Layer, and Blue Layer bands, then Load RGB to display a true-color Landsat TM image. 3.Select File Open External FileIP Software ER Mapper, navigate to the lontmsp subdirectory and select the file lon_spot.ers. 1 4.Click on the Gray Scale radio button in the Available Bands List, click on the Pseudo Layer band, select New Display from the pull-down Display menu, then click Load Band to display the gray scale SPOT image. 二、调整影像大小 1.Click first on the SPOT image band in the Available Bands List and note its spatial dimensions (2820 x 1569) and then click on the Landsat TM and note its spatial dimensions (1007 x 560). The Landsat data have a spatial pixel size of 28 meters, while the SPOT data are 10 meter spatial resolution. The Landsat image has to be resized by a factor of 2.8 to create 10 m data that matches the SPOT data. 2.Select Basic Tools Resize Data (Spatial/Spectral) and choose the lon_tm image then click OK. Enter a value of 2.8 into the xfac text box in the Resize Data Parameters dialog. Enter a value of 2.8009 into the yfac text box (the value of 2.8009 rather than 2.8 must be used to add an extra pixel to the y dimension so the images will match exactly). This difference is insignificant for the purposes of this exercise, but might be important for an actual application. Enter an output filename and click OK to resize the TM image. 3.Display the resized image and select Tools Link Link Displays to link the resized TM image and the SPOT Panchromatic image. Use the dynamic overlay to compare the two images. 三、手动HSI数据融合 1.HSV正变换 1)Select Transform Color Transforms RGB to HSV from the ENVI main menu, and select the resized TM data as the RGB image from the Display. Enter an output filename and click OK to perform the transform. 2)Display the Hue, Saturation, and Value images as gray scale images or an RGB. 2.拉伸SPOT影像并替换TM的数值波段 1)Select Basic Tools Stretch Data from the ENVI main menu, click on the lon_spot file and then OK. 2)In the Output Data portion of the Data Stretching dialog, enter the value 0 for the Min and 1.0 for the Max values, enter an output filename, and click OK to stretch the SPOT data to floating point data with a range of 0 to 1.0. 2 3.HSV反变换 1)Select Transform Color Transforms HSV to RGB from the ENVI main menu, and select the transformed TM Hue and Saturation bands as the H and S bands for the transformation. 2)Choose the stretched SPOT data as the V band for the transform, click OK. Enter an output filename into the HSV to RGB Parameters dialog and click OK to perform the inverse transform. 4.结果显示 1)Click on the RGB Color radio button in the Available Bands List, click sequentially on the transformed R, G, and B bands, then click the Load RGB button to display a fused true-color Landsat TM/SPOT image. 2)Display the fused image and select Tools Link Link Displays to link with the resized TM image and the SPOT Panchromatic image. Use the dynamic overlay to compare the images. 四、自动HSV变换融合 1.Select Transform Image Sharpening HSV from the ENVI main menu. 2.If you have the resized TM color image displayed, choose the appropriate display in the Select Input RGB dialog. Otherwise, choose the “Red Layer”, “Green Layer”, and “Blue Layer” from the resized TM Image in the Select Input RGB Input Bands dialog and click OK. 3.Choose the SPOT image in the High Resolution Input File dialog and click OK. 4.Enter the output file name lontmsp.img and click OK in the HSV Sharpening Parameters dialog. 五、结果显示、链接和比较 5.Load the fused color image into a new display by selecting the RGB Color radio button in the Available Bands List dialog, selecting the R, G, and B bands from the new file and clicking Load RGB. 6.Compare the HSV sharpened color image to the original TM color composite, to the SPOT data, and to the manual data fusion result by selecting Tools Link Displays Link from the Main Display Window menu bar. 六、结束ENVI 3