There is no tool in ENVI to do this but a function could be written in IDL. I created a program many years ago that would run in ENVI Classic but it should still work in ENVI 5.x. You could try the below: pro max_min_value, ev compile_opt IDL2 ;select input file and gather information envi_select, fid=fid, dims=dims, pos=pos, title = 'Select an input file' if (fid eq -1) then return envi_file_query, fid, ns=ns, nl=nl, nb=nb, data_type=dt, interleave=interleave, $ xstart=xstart,ystart=ystart, fname=fname, dims=dims inherit = envi_set_inheritance(fid, dims, /spatial) ;set the output name base = widget_auto_base(title='Output file name') wo = widget_outf(base, uvalue='outf', /auto) result = auto_wid_mng(base) if (result.accept eq 0) then return out_name=result.outf ;open a file to write and initialize tiling openw, unit, out_name, /get_lun tile_id = envi_init_tile(fid, pos, num_tiles=num_tiles, $ interleave=(interleave > 1), xs=dims[1], xe=dims[2], $ ys=dims[3], ye=dims[4]) envi_report_init, ['Input file: '+fname,'Output file: '+out_name], $ title='Calculating Min/Max values...', base=base envi_report_inc, base, num_tiles ;start process tiling for i=0L, num_tiles-1 do begin envi_report_stat, base, i, num_tiles, cancel=cancel if cancel eq 1 then begin envi_report_init, base=base, /finish return endif data = envi_get_tile(tile_id, i) maxdata = max(data, dimension=2, min=mindata) maxdata=reform(maxdata, ns, 1, /overwrite) mindata=reform(mindata, ns, 1, /overwrite) writeu, unit, [[maxdata], [mindata]] endfor envi_report_init, base=base, /finish free_lun, unit envi_tile_done, tile_id ;create ENVI header for output envi_setup_head, fname=out_name, ns=ns, nl=nl, nb=2, $ data_type=dt, offset=0, interleave=1, /write, /open, $ xstart=xstart+dims[1], ystart=ystart+dims[3], $ bnames=['Max value', 'Min value'], inherit=inherit envi_tile_done, tile_id end