Motion tracking dot removal

[Stewart McDonald]

I have done some testing with motion tracking. The footage has come out great, but I would like to remove the coloured dots I have that are still visible in the scene. Anyone know the best way? I can't film the shot again with no dots as it was hand held.

Thanks

[Robert Knecht Schmidt]

Stewart,

Both Adobe After Effects and discreet combustion have tools to do this kind of paint work.

The basic procedure is to assign a clone brush to follow 2D trackers tacked on to your marker points. The shape and size of the clone brush, number of strokes, etc. will require tweaking to achieve the best result. No matter what, you will have a sophisticated job on your hands that might require frame-by-frame attention. Expect to spend a day or more painting out those little guys!

If you use combustion, these tutorials will get you started. (Of particular help to your case will be the second half of Lesson 4, "Using Paint," in which a power cable is painted out of a skyscape, and the first half of Lesson 5, which describes using trackers.)

Good luck! We'd love to see how it goes if you ever get a chance to post before-and-afters.

[Stewart McDonald]

Thanks I'll look into it.

[Rob Lohman]

I've read somewhere that someone used a secondary color
corrector to change the color of the dots after the footage was
tracked to the same color as the screen and thus being picked
up by the matte removal software. I can imagine this will
probably only work on dots that have a color not found in the
rest of the scene (flourecent pink etc.). Or you might make a crude
"travelling" matte first to cover only the dot area and put that
through a secondary corrector if the color also is in some other
parts of the scene

[Robert Knecht Schmidt]

If the dots are on a key screen, then there's no need for painting them out. A garbage matte will get rid of them.

[Rob Lohman]

Can you elaborate a bit on that Robert?