Thanks for your reply, so if i wanted to specify a window size of 5 (for example) i should iterate from 1 to size - 4? Thanks. Marco -- View this message in context: http://itk-users.7.n7.nabble.com/ITK-users-Texture-Features-extraction-tp34642p34644.html Sent from the ITK - Users mailing list archive at Nabble.com.