做图形旋转时，IDL下标超出范围,求大神指教

XXL昊

pro imageEhance

ENVI_SELECT, title='choose two file', fid=in_fid

   ENVI_FILE_QUERY, in_fid, ns=ns, nl=nl, nb=nb, fname=fname

   OpenR, unit, fname, /Get_LUN

   info = FSTAT(unit)

   Free_LUN, unit

   print, 'you selected ',fname

   print, 'number of samples = ',ns

   print, 'number of lines = ',nl

   print, 'number of bands = ',nb

   print, 'file size in bytes = ',info.size

   dims = [-1, 0, ns-1, 0, nl-1]

   fid =in_fid

   GET_LUN,U

   PixelVal = ULINDGEN(ns, nl,3)

   Pixel=ULINDGEN(round(ns*2),round(nl*2),3)

   Pixel(*,*,*)=0

   nb_i=0

   for k=0,2 do begin

    PixelVal(*,*,k)= ENVI_GET_DATA(fid=fid, dims=dims, pos=k)

    for j=0,nl-1 do begin

     for i=0,ns-1 do begin

     x=round(i*cos(!pi/6)-j*sin(!pi/6))     ;旋转30°,60°为!pi/3,45°为!pi/4,90°为!pi/2

     y=round(i*sin(!pi/6)+j*cos(!pi/6))

     Pixel(x+ns,y+nl,k)=PixelVal(i,j,k)

     endfor

    endfor

    for j=0,round(ns*2)-2 do begin

     for i=0,round(nl*2)-1 do begin

      if(Pixel(i,j,k) eq 0 ) then begin

      Pixel(i,j,k)=Pixel(i,j+1,k)

      endif

     endfor

    endfor

   endfor

   close,fid

   close,U

   free_lun, U

   ENVI_WRITE_ENVI_FILE,Pixel,out_name='enchancedImage.img'

   showEnd=dialog_message('读取完毕')

   END

这个程序本身是没有问题的，但是最后显示的是subscript out of range,我用的版本是ENVI4.3。我想知道哪边需要改的，谢谢啦