Hi all, I have been trying to mask an image by using an ROI based on an EVF. I referenced this posting: http://www.idl-envi.com/l...980/scope/posts.aspx It worked correctly but some information was missing. I read this posting: http://www.exelisvis.com/...233/scope/posts.aspx that ENVI includes pixels in the mask if it the scan lines are considered to pass through the center of each row of pixels. Pixels are activated if the center of the pixel is to the right of the intersection of the scan line and the polygon edge within the interval. Besides this I would also like to include the border pixels which are "touched" by the EVF boarder line. what I mean is that even though the border pixel is covered by less than 10% of the EVF border line, it also has to be masked as in. Does anyone know how to do this? Thank you very much in advance. Ciao