Hi I am just learning IDL and have a jpg image (522 pixels by 14000) pixels that has been 'cork screwed'. There 4 distinct bands (4 to 6 pixels wide with value 240 to 255 in the Blue band) showing the 'cork screwing' running along the 14000 pixel length. I would like to extract the coordinated of these 4 features as an array. I then propose to use one of the column from the array as an in put to the script '1178:shifting lines by Jan Eitel' - University of Idaho posted on 9/29/2005 and modified by '1188:shifting lines by Tech Support' - ITT Visual Information Solutions 10/3/2005 . Seems to me that this would correct the 'cork screw' (if I could do it!) but I am open to any other suggestion. Any help will be greatly appreciated Alasdair, University of Edinburgh Any help