Hello, everyone. I want to batch subset images via ROI by IDL programing, and I also want to mask the data that outside the ROI at the meantime. I find an example on the website, however, this example is only subset the data by squire shape. The following is the my revised codes: PRO Subset_via_roi ENVI, /RESTORE_BASE_SAVE_FILES ENVI_BATCH_INIT, LOG_FILE='batch.txt' ; define the image to be opened szPath = 'E:\Rubber\IDL&ENVI\Subset' filters = ['*.img','*.tif'] img_file = DIALOG_PICKFILE(PATH=szPath,TITLE='Select Image for Subset',FILTER=filters) IF (img_file EQ "") THEN RETURN ENVI_OPEN_FILE,img_file,R_FID=fid PRINT, 'fid=',fid ; query the file and define the output file variables ENVI_FILE_QUERY,fid,DIMS=dims,NS=ns,NL=nl,NB=nb t_fid=LONARR(nb)+fid pos=LINDGEN(nb) out_name=szPath + '\subset.img' ;open the EVF file evf_file = DIALOG_PICKFILE(PATH=szPath,TITLE='Select Vector File to create ROI',FILTER=['*.evf','*.shp']) IF (evf_file EQ "") THEN RETURN evf_id=ENVI_EVF_OPEN(evf_file) ;get the vector information ENVI_EVF_INFO,evf_id,NUM_RECS=num_recs,DATA_TYPE=data_type,PROJECTION=projection,$ LAYER_NAME=layer_name ; print information about each record PRINT, 'Number of records:',num_recs FOR i=0,num_recs-1 DO BEGIN record=ENVI_EVF_READ_RECORD(evf_id,i) ;PRINT, 'Number of nodes in Record '+STRTRIM(i+1,2)+':',N_ELEMENTS(record[0,*]) ;PRINT, 'Record Info:' ;PRINT, record ENDFOR ; Get record info (assuming one record in EVF) record=ENVI_EVF_READ_RECORD(evf_id,0) ; Result[0, *] contains the x values, and Result[1, *] contains the y values xMap=record[0,*] yMap=record[1,*] roi_id = ENVI_CREATE_ROI(COLOR=4, NAME='Danzhou roi', NS=ns, NL=nl) ; Define the roi ENVI_DEFINE_ROI, roi_id, /POLYGON, XPTS=xMap, YPTS=yMap ;roi_data = ENVI_GET_ROI_DATA(roi_id,POS=pos,FID=t_fid) ;Convert record to xy pixel coordinates of the image to be subsetted ENVI_CONVERT_FILE_COORDINATES,fid,xf,yf,xMap,yMap ;Prepare the subset dimensions dims[0]= ENVI_GET_ROI_DIMS_PTR(roi_id) ;-1L ; A Pointer to the Opened ROI dims[1]=min(xf)-1 ; The starting sample number, the first x pixel is 0 dims[2]=max(xf)-1 ; The Ending sample number dims[3]=min(yf)-1 ; The starting line number, the first y pixel is 0 dims[4]=max(yf)-1 ; The ending line number. ;Use copyfile_doit to copy input file with new dimensions ENVI_DOIT,'CF_DOIT',FID=t_fid,POS=pos,DIMS=dims,REMOVE=0,OUT_NAME=out_name,R_FID=r_fid ; Exit Envi ENVI_BATCH_EXIT END The codes in red color is added for testing. However, it does not work, the output results is also squire shape. Any help is appreciated.