ENVI 5的试用-更方便快捷的ENVI功能扩展

ENVI5.0对ENVI启动、数据读取、显示窗口、处理函数API进行了更新，增加了工具箱扩展流程，更新的API函数更加简洁，使用更加方便。下面首先对ENVI启动、数据读取、显示窗口控制等功能进行代码示例展示，然后利用这些功能代码结合工具箱扩展流程编写一个ENVI扩展工具实例。

1<wbr><wbr><wbr><wbr> ENVI启动</wbr></wbr></wbr></wbr>

代码简化了启动，使得在启动ENVI的代码更加简洁、直观。IDL的命令行下启动ENVI只需要输入代码：

e=ENVI()

二次开发模式下输入代码：

ENVI5.0代码	之前版本代码
e=ENVI(/Headless)	ENVI, /RESTORE_BASE_SAVE_FILES ENVI_BATCH_INIT

2<wbr><wbr><wbr><wbr> 数据读写</wbr></wbr></wbr></wbr>

之前版本中，ENVI依靠文件的ID号即FIDs来进行栅格文件的操作。ENVI5.0下可以通过新的API接口返回值来进行直接处理。比如对栅格文件的读写操作示例代码：

ENVI5.0代码

;启动ENVI e = ENVI(/HEADLESS) <wbr></wbr> ;打开文件 file = FILEPATH('qb_boulder_msi', ROOT_DIR = e.root_dir, $ <wbr><wbr><wbr>SUBDIR=['data'])</wbr></wbr></wbr> raster = e.OpenRaster(file) ;读取影像的第一个波段 data = raster.GetData(BANDS = 0) <wbr></wbr> ;另存为新文件 resultFile = e.GetTemporaryFilename('.dat') newRaster = e.CreateRaster(resultFile, data, INHERITS_FROM = raster) newRaster.Save <wbr></wbr>

5.0之前版本代码

;启动ENVI ENVI, /RESTORE_BASE_SAVE_FILES ENVI_BATCH_INIT <wbr></wbr> ;打开文件 file = FILEPATH('qb_boulder_msi', ROOT_DIR=ENVI_GET_PATH(), $ <wbr><wbr><wbr>SUBDIR=['..','data'])</wbr></wbr></wbr> ENVI_OPEN_FILE, file, R_FID = fid ENVI_FILE_QUERY, fid, DIMS = dims <wbr>;读取影像的第一个波段</wbr> data = ENVI_GET_DATA(FID = fid, DIMS = dims, pos = 0) <wbr></wbr> ;另存为新文件 inherit = ENVI_SET_INHERITANCE(fid, dims) resultFile = FILEPATH('qb_boulder_msi_classic_band0.dat', /TMP) ENVI_WRITE_ENVI_FILE, data, INHERIT = inherit, R_FID = r_fid, $ <wbr><wbr><wbr>OUT_NAME = resultFile</wbr></wbr></wbr> ENVI_BATCH_EXIT

3<wbr><wbr><wbr><wbr> 窗口控制</wbr></wbr></wbr></wbr>

在IDL下可以通过代码进行数据图层、显示窗口绘制等操控处理。

<wbr></wbr>ENVI5.0代码

;启动ENVI e = ENVI() <wbr></wbr> ;打开两个文件 file1 = FILEPATH('qb_boulder_pan', ROOT_DIR = e.root_dir, $ <wbr><wbr><wbr>SUBDIRECTORY = ['data'])</wbr></wbr></wbr> file2 = FILEPATH('qb_boulder_msi', ROOT_DIR = e.root_dir, $ <wbr><wbr><wbr>SUBDIRECTORY = ['data'])</wbr></wbr></wbr> raster1 = e.OpenRaster(file1) raster2 = e.OpenRaster(file2) <wbr></wbr> ;在两个独立的窗口中显示 view1 = e.GetView() view1_layer = view1.CreateLayer(raster1) view2 = e.CreateView() view2_layer = view2.CreateLayer(raster2) <wbr></wbr> ;在一个窗口中显示 view3 = e.CreateView() view3_layer1 = view3.CreateLayer(raster1) view3_layer2 = view3.CreateLayer(raster2) portal = view3.CreatePortal() <wbr></wbr> ;窗口进行关联显示 view1.GeoLink, /LINK_ALL <wbr></wbr> ;窗口视图中心点移动到指定坐标位置 view1.GoToLocation,482234.9000d,4427500.7000D,/map

5.0之前版本代码

;启动ENVI ENVI <wbr></wbr> ;打开两个文件 file1 = FILEPATH('qb_boulder_pan', ROOT_DIR = ENVI_GET_PATH(), $ <wbr><wbr><wbr>SUBDIRECTORY = ['..','data'])</wbr></wbr></wbr> file2 = FILEPATH('qb_boulder_msi', ROOT_DIR = ENVI_GET_PATH(), $ <wbr><wbr><wbr>SUBDIRECTORY = ['..','data'])</wbr></wbr></wbr> ENVI_OPEN_FILE, file1, R_FID = fid1 ENVI_OPEN_FILE, file2, R_FID = fid2 <wbr></wbr> ;在两个独立的窗口中显示 ENVI_DISPLAY_BANDS, fid1, 0, /new ENVI_DISPLAY_BANDS, fid2, [2,1,0], /new <wbr></wbr> ;获取窗口的ID号 Get the display numbers displays = ENVI_GET_DISPLAY_NUMBERS() <wbr></wbr> ; 窗口视图中心点移动到指定坐标位置 ENVI_CONVERT_FILE_COORDINATES, fid1, XF, YF,482234.9000d,4427500.7000D DISP_GOTO, displays[0], XF, YF ENVI_CONVERT_FILE_COORDINATES, fid2, XF, YF,482234.9000d,4427500.7000D DISP_GOTO, displays[1], XF, YF

4<wbr><wbr><wbr><wbr> 数据处理</wbr></wbr></wbr></wbr>

数据处理时，可以在现在的数据操控基础上转换调用ENVI的处理函数进行。

;启动ENVI

e = ENVI()

<wbr></wbr>

;打开一数据文件

file = FILEPATH('qb_boulder_msi', ROOT_DIR = e.ROOT_DIR, $

<wbr><wbr><wbr>SUBDIRECTORY = ['data'])</wbr></wbr></wbr>

raster = e.OpenRaster(file)

<wbr></wbr>

;设置输出文件名

out_file = e.GetTemporaryFilename()

<wbr></wbr>

;转换为Fid（File ID）

fid = ENVIRasterToFID(raster)

<wbr></wbr>

;利用Fid进行处理，获取处理后的r_fid

ENVI_FILE_QUERY, fid, DIMS=dims

ENVI_DOIT,'CONV_DOIT', FID=fid, $

<wbr><wbr><wbr>DIMS=dims, OUT_NAME=out_file, $</wbr></wbr></wbr>

<wbr><wbr><wbr>METHOD=0, R_FID=r_fid</wbr></wbr></wbr>

<wbr></wbr>

;转换r_fid为ENVI的栅格对象

out_raster = ENVIFIDToRaster(r_fid)

<wbr></wbr>

;在显示窗口中显示原图和处理后结果

view = e.GetView()

layer1 = view.CreateLayer(raster)

layer2 = view.CreateLayer(out_raster)

portal = view.CreatePortal()

5<wbr><wbr><wbr><wbr> 工具箱扩展</wbr></wbr></wbr></wbr>

基于ENVI提供的数据读写、窗口控制和数据处理函数可以方便的实现ENVI工具箱的扩展。IDL中提供了ENVI工具箱扩展向导来扩展工具箱。以在ENVI的工具箱下添加浮雕效果处理功能为例，扩展工具箱的基本步骤如下：

1)<wbr><wbr><wbr><wbr><wbr><wbr><wbr> 新建ENVI扩展</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

单击IDL菜单文件-新建ENVI扩展，弹出如下界面，工程名称为“em_boss”，扩展名称为“em_boss”，IDL程序名称为“envi_em_boss_extension”，扩展路径为“ImageProcessing”。

点击完成后，会在当前工作空间中建立名为emboss的工程，并包含了一个完整的代码框架。框架内容如下：

; Add the extension to the toolbox. Called automatically on ENVI startup.

pro my_extension_extensions_init

<wbr> ; Set compile options</wbr>

<wbr> compile_opt IDL2</wbr>

<wbr></wbr>

<wbr> ; Get ENVI session</wbr>

<wbr> e = ENVI(/CURRENT)<wbr></wbr></wbr>

<wbr> ; Add the extension to a subfolder</wbr>

<wbr> e.AddExtension, 'emboss', 'my_extension', PATH='I:\program files\Exelis\ENVI50\extensions'</wbr>

end

<wbr></wbr>

; ENVI Extension code. Called when the toolbox item is chosen.

pro my_extension

<wbr> ; Set compile options</wbr>

<wbr> compile_opt IDL2</wbr>

<wbr></wbr>

<wbr> ; General error handler</wbr>

<wbr> CATCH, err</wbr>

<wbr> if (err ne 0) then begin</wbr>

<wbr><wbr><wbr> CATCH, /CANCEL</wbr></wbr></wbr>

<wbr><wbr><wbr> if OBJ_VALID(e) then $</wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr> e.ReportError, 'ERROR: ' + !error_state.msg</wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr> MESSAGE, /RESET</wbr></wbr></wbr>

<wbr><wbr><wbr>return</wbr></wbr></wbr>

<wbr> endif<wbr></wbr></wbr>

<wbr> ;Get ENVI session</wbr>

<wbr> e = ENVI(/CURRENT)<wbr></wbr></wbr>

;******************************************

; Insert your ENVI Extension code here...

;******************************************

<wbr></wbr>

end

2)<wbr><wbr><wbr><wbr><wbr><wbr><wbr> 编写处理功能代码</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

在框架代码的标识处、添加编写输入输出和处理图像的功能代码如下：

<wbr> ;打开输入文件</wbr>

<wbr> inFile=DIALOG_PICKFILE(DIALOG_PARENT=e.WIDGET_ID, $</wbr>

<wbr><wbr><wbr> TITLE='Please select input file',$</wbr></wbr></wbr>

<wbr><wbr><wbr> /MUST_EXIST)</wbr></wbr></wbr>

<wbr><wbr><wbr></wbr></wbr></wbr>

<wbr> ;选择输出文件</wbr>

<wbr> outFile=DIALOG_PICKFILE(DIALOG_PARENT=e.WIDGET_ID, $</wbr>

<wbr><wbr><wbr> TITLE='Please select output file')</wbr></wbr></wbr>

<wbr><wbr><wbr></wbr></wbr></wbr>

<wbr> ;打开并显示</wbr>

<wbr> raster = e.OpenRaster(inFile)</wbr>

<wbr> view=e.GetView()</wbr>

<wbr> layer1=view.CreateLayer(raster, BANDS=[0])</wbr>

<wbr></wbr>

<wbr> ;创建文件输出</wbr>

<wbr> rasterNew = e.CreateRaster(outFile, INHERITS_FROM=raster)</wbr>

<wbr></wbr>

<wbr> ;获取栅格的分块数</wbr>

<wbr> tiles = raster.CreateTileIterator(BANDS=[0])</wbr>

<wbr> ;依次处理</wbr>

<wbr> FOREACH tile, Tiles DO BEGIN</wbr>

<wbr><wbr><wbr> data = EMBOSS(tile, /EDGE_WRAP)</wbr></wbr></wbr>

<wbr><wbr><wbr> rasterNew.SetTile, Data, Tiles</wbr></wbr></wbr>

<wbr> ENDFOREACH</wbr>

<wbr></wbr>

;保存文件

<wbr> rasterNew.Save</wbr>

<wbr> ;新增显示图层</wbr>

<wbr> layer2 = view.CreateLayer(rasterNew)</wbr>

<wbr></wbr>

<wbr> ;卷帘显示并动态切换</wbr>

<wbr> portal = view.CreatePortal()</wbr>

<wbr> portal.Animate</wbr>

3)<wbr><wbr><wbr><wbr><wbr><wbr><wbr> 生成sav文件</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

右击工程名称“em_boss”，弹出菜单中选择“构建工程”，会生成“envi_em_boss_extension.sav”文件。

4)<wbr><wbr><wbr><wbr><wbr><wbr><wbr> 使用扩展</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

将生成的“envi_em_boss_extension.sav”文件拷贝到ENVI50安装目录的扩展目录下，默认为“c:\program files\Exelis\ENVI50\extensions”，启动ENVI，在工具箱下会发现新增加的扩展工具。

<wbr></wbr>

双击执行工具，选择输入文件和输出文件名，工具会对图像进行处理，并将原始图像与处理后图像动态叠加显示。

<wbr><br></wbr>