Hi Forumer, Can you please suggest me, How I can subset ( clip) an image to the the shape of polygon ( not rectangle) uisng ENVi or IDL. I tried using ROI and other methods given in the Help, but it always clips to a rectangle. I need to subset the iamge exactly to the shape of the polygon. ( lfor example shape of UAE country ). This can be done easly using ERDAS, ArcGRID and in simple software like GlobalMapper. but I could'nt figure it out in ENVI. Is there a way ????