If the two preconditions for an affine relationship are met: The collinearity <http://en.wikipedia.org/wiki/Line_(geometry)> relation between points; i.e., the points which lie on a line continue to be collinear after the transformation Ratios of distances along a line; i.e., for distinct collinear points *p*1,* p*2,*p*3, the ratio | *p*2 - *p*1 | / | *p*3 - *p*2 | is preserved
Then solve the affine transformation relationships: if X is the source image feature point locations and Y is the target image feature point locations and they are related by an affine transform (rotations + transformations) then you can create an affine transformation equation. Y = A X + b or Y = A' X where A' is the homogeneous representation of the Affine transform. Solve this set of equations and ensure consistency (no. of variables < no. of equations). If you don't know which feature point maps to which other, then solve the equations for all possible combinations and see which one fits the best. (You'll have to be slightly lax about the consistency constraints). You may want to see the LUP algorithm for solving equations in matrix form. Also see: http://en.wikipedia.org/wiki/Affine_transformation (section: affine transformations of a plane) -- DK http://twitter.com/divyekapoor http://www.divye.in -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To view this discussion on the web visit https://groups.google.com/d/msg/algogeeks/-/z9x9sVs3eCoJ. To post to this group, send email to algogeeks@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
