What is mem_res? Can you provide a help, mem_res so we can see what sort of array it is? If you do a quick stats on the entry in ENVI, does it show all 0s or actual values?

Thanks MariM for your reply. I doing in this way where ns and nl are number of lines and sample. I intentionally make few elements equal to 5 but it is not required in actual code. mem_res = fltarr(ns, nl) mem_res = reform(score,ns,nl) mem_res[600:614, 800:815] = 5.0 print, mem_res if result.outf.in_memory EQ 1 THEN BEGIN ; If the user wanted the result to go to memory then just output it there ENVI_ENTER_DATA, mem_res help, mem_res endif Another surprising thing as you mentioned i did help, mem_res it says undefined.the output is MEM_RES UNDEFINED = I do not know why. As you see i am printing the values aswell. The printing is alright even i right the .img file. It shows nothing in envi when i load but if i open it in matlab and draw as image. It shows different values. Thanks in advance

ENVI_ENTER_DATA deletes the variable that is passed into it. So it is expected that mem_res would be undefined after the call to ENVI_ENTER_DATA. Can you try using the HELP command on mem_res before you call ENVI_ENTER_DATA, so we can see what it is before that? Peg Exelis VIS