4 Replies Latest reply on Mar 8, 2016 10:32 AM by Rick Gerard

    Fix book cover in green screen video


      I have a video shot in front of a green screen. There is a book with a reflective cover that is keying out because it reflected the green from the floor. I am looking for the best way to either mask out the book itself so that the key effect isn't applied, or replace the book cover with some type of "tin foil" texture image that is consistent with the tin man character. The book moves during the footage, so I have to track this as well. Any suggestions? I am hoping to avoid having to go frame-by-frame because the clip is almost 10 minutes long. However, I realize that may not be an option. Screenshots attached.


      Screenshot 1 (Tin Man holding the book)



      Screenshot 2 (Tin Man turning book)



      Screenshot 3 (Another Tin Man holding book shot)



      Screenshot 4 (With Keylight applied in After Effects)


        • 1. Re: Fix book cover in green screen video
          Szalam Adobe Community Professional & MVP

          You'll probably have to rotoscope the book. I'd try just desaturating it. That way it'll still look shiny, but it won't look green.

          • 2. Re: Fix book cover in green screen video
            justins25110601 Level 1

            Is there an easier way to rotoscope the book? With the book color matching the surrounding colors, I would most likely have to adjust every frame, right? If you had to do it, how would you go about rotoscoping the book out?

            • 3. Re: Fix book cover in green screen video
              Szalam Adobe Community Professional & MVP

              I wouldn't go every frame at first. Basic roto techniques would apply!

              Set keyframes at extreme positions and then go halfway between those keyframes and adjust. Then halfway between those and adjust again. You may eventually have a mask shape keyframe on every frame, but you'll get there a lot faster. More tips here: After Effects Help | Managing and animating shape paths and masks

              • 4. Re: Fix book cover in green screen video
                Rick Gerard Adobe Community Professional & MVP

                First, are you going to use the entire 10 minute take in the production. That's an awful long time to go on a single shot. If not, pre-edit the piece so you only have to work on the parts of the shot you are going to use plus a few frames for "handles" to allow for some fine adjustments in the final edit.


                Second, when you roto you'll probably only have to do the polygon that describes the book. You should be able to rely on keying to cut out around the fingers. You'll just have to layer the composite properly.


                This kind of manual roto can go very quickly. I almost always Stabilize motion picking a point that I want to hold still, then add a colored layer with a blend mode so I can see through it and do the roto masking on the solid. When the roto works I remove the stabilization by adding a null and adding expressions to tie the position of the null to the anchor point of the 'stabilized' layer and then parent the track matte and the footage to the null. EZ as pie. Here's a quick tutorial on the process.

                The null and parenting trick works much better than what I did here.