4 Replies Latest reply on Sep 24, 2012 2:11 AM by peter_101

    Pinning tracked image elements to corners of comp


      Hoping to get some help with some tracking / stabilization work.


      I've got a sequence of 35mm film scans (at 6K) which were originally recorded to film with reference marks in the four corners of the frame. These marks were intended for stabilization of the footage if it were ever rescanned, and as a reference to the resolution and geometry of the original source content (i.e. I know the width and height in pixels between each of the reference marks in the original frames).


      What I'm trying to do in AE (CS6, Mac OS 10.8) is track the four reference marks through the length of the sequence, then pin those tracked marks to the corners of a composition whose resolution matches that of the original content. This should stabilize the scans and correct the geometry (scale, rotation, warp) all in one pass.


      Is this something that's possible in AE (tracking points and pinning them within a comp)? Cause for the life of me I can't figure out how to do it.

        • 1. Re: Pinning tracked image elements to corners of comp
          Mylenium Most Valuable Participant

          Sure. Simply track them as a corner pin, then do some simple math. Some thing to get you started is here:




          You basically just figure out the difference of the pin positions vs. the comp and then add it onto the pin values to move them to the edges. Depending on what the film does, you may need additional corrections using distortion effects. Also you may wanan substitute AE's corner pin for a better product like Red Giant Warp or RevisionFX' RE:Map pin effect. Come to think of it.... those even have to/ from warping options, so you wouldn't need the expressions.



          • 2. Re: Pinning tracked image elements to corners of comp
            peter_101 Level 1

            Thanks Mylenium,


            Got almost exactly what I needed with a demo of the RE:Map effect.  Now I just need to get the boss to let me buy the license.  :-)


            The only downside of the plugin is that it is a true inverse corner-pin, so that the tracked points are pinned to the corners of the layer.  I'm now working on creating expressions to be able to pin the four tracked points to completely arbitrary positions within the composition frame (this project is getting more and more complicated at every turn).  What fun!  :-D

            • 3. Re: Pinning tracked image elements to corners of comp
              Fuzzy Barsik Level 4

              Well, if CatMan properly understands the task, you can track reference marks in Mocha and then either create stabilised pre-comp in almost one click with MochaImport script or just import tracking data manually, stabilise a layer and then drop it into a comp with the required size...

              • 4. Re: Pinning tracked image elements to corners of comp
                peter_101 Level 1

                Hi CatMan.  :-)


                That's kind of what I'm doing, but for basic point tracking (these are very clean, clearly visible tracking markers in the frame) I actually prefer the AE tracker to the Mocha planar tracker.  But you're right, the Mocha / MochaImport / RGWarp (pre-comp) workflow should produce effectively the same result.  Just with RE:Map I can do it in one application and a few less steps.