首先在ENVI当中建立ROI，然后保存成XML格式
利用下面代码的
raster = e.OpenRaster(file)和
raster.ExportRois,infilepath+'incidence_angle_sample.csv' , rois, 'CSV'
就可以实现按照ROI统计的影像信息的CSV
打开生成的CSV后得到
?RO1 #1 类别 npts（像素个数）: 320
?RO1 #2 类别 npts（像素个数）: 320
B1、B2、B3为影像的波段1、2和3的像素值
最后用READ_CSV打开该文件
hh=roicsv.FIELD7; 读取B1
hv=roicsv.FIELD8;读取B2
angle=roicsv.FIELD9;
pro data_select_by_roi
COMPILE_OPT IDL2
; Start the application
e = ENVI(/HEADLESS)
ys=2016;
ye=2021;
ms=1;
me=4;
for yr=ys,ye do begin
for mon=ms,me do begin
infilepath='H:\Lead\data\sample\'+STRING(yr, FORMAT='(I04)')+'\'+STRING(mon, FORMAT='(I01)')+'\'
cd,infilepath
tifdata = file_search('S1*.tif',count = num);infilepath,
if num eq 0 then begin
print,infilepath,' has no tif file.'
continue
endif
; Open an input raster
file = FILEPATH(tifdata[0], ROOT_DIR=infilepath);
raster = e.OpenRaster(file)
; Open an ROI file
; roiname=infilepath+'incidence_angle_sample.xml'
file = FILEPATH('incidence_angle_sample.xml', ROOT_DIR=infilepath);, SUBDIRECTORY = ['data']
rois = e.OpenRoi(file)
if file_test(infilepath+'incidence_angle_sample.csv') eq 0 then begin
raster.ExportRois,infilepath+'incidence_angle_sample.csv' , rois, 'CSV'
print,'文件新建'
endif
roicsv = READ_CSV( infilepath+'incidence_angle_sample.csv' ,N_TABLE_HEADER=13,TYPES='Float')
filenum=N_elements(roicsv.FIELD1);
x=roicsv.FIELD1;
y=roicsv.FIELD2;
hh=roicsv.FIELD7;
hv=roicsv.FIELD8;
angle=roicsv.FIELD9;
flag=0
for i=0,filenum-1 do begin
;搜集数据
if i eq 0 or ((i mod 16) eq 0) then begin
temp1=[hh[i]]
temp2=[hv[i]]
temp3=[angle[i]]
endif else begin
temp1=[temp1,hh[i]]
temp2=[temp2,hv[i]]
temp3=[temp3,angle[i]]
endelse
;判断是否需要提交结果
if i ne 0 and (N_elements(temp1) eq 16) then begin ;判断是否与前一个不为同ROI abs(x[i-1]-x[i]) gt 5 and abs(y[i-1]-y[i])
if flag eq 0 then begin ;判断是否第一次建立结果数组
result1=mean(temp1)
result2=mean(temp2)
result3=mean(temp3)
flag=1
endif else begin
result1=[result1,mean(temp1)]
result2=[result2,mean(temp2)]
result3=[result3,mean(temp3)]
endelse
endif
endfor
if yr gt 2017 or (yr eq 2017 and mon ge 3) then begin
final_ice=[[result1[0:19]],[result2[0:19]],[result3[0:19]]]
final_ice=Transpose(final_ice)
final_ow=[[result1[20:-1]],[result2[20:-1]],[result3[20:-1]]]
final_ow=Transpose(final_ow)
endif else begin
final_ow=[[result1[0:19]],[result2[0:19]],[result3[0:19]]]
final_ow=Transpose(final_ow)
final_ice=[[result1[20:-1]],[result2[20:-1]],[result3[20:-1]]]
final_ice=Transpose(final_ice)
endelse
WRITE_CSV,infilepath+'HH_HV_incidence_angle_statistics_ow.csv',final_ow
WRITE_CSV,infilepath+'HH_HV_incidence_angle_statistics_ice.csv',final_ice
print,'hello',infilepath+'HH_HV_incidence_angle_statistics.csv'
endfor
endfor
end
