When applying control points to the vectorized map, which method should be used, Bi-Linear or Triangulation?
Both the Bi-Linear and Triangulation methods will generate a geometric transform to project your vectorized map data from one coordinate system (most likely the raw image coordinate system) to another (most likely the map projection system you are going to use in a GIS software). However, the two methods work quite differently and you should select the one most suitable to your application. Here are some guidelines for selecting the method that is right for you: A. Bi-Linear corrects global distortion more effectively while Triangulation corrects local distortion better. The Bi-Linear method uses least-squares to generate one transform formula for the entire image no matter how many control points you have selected. Control point locations are not guaranteed to be at the exact same location after the transformation. So if you do not have too much local distortion and have a small number of control points, say 4 points at the corners, the Bi-Linear method is suggested. B. The Triangulat
