Keying is rarely a simple matter of picking the screen color you want to remove. To get the very best mattes, you often need to combine several techniques and you’ve learned several in this chapter. You’ve pulled mattes with Primatte and Nuke’s Image-based Keyer, and you’ve used the rotoscoping tools to cleanup a matte and control the parts of the image you want to use in the composite.
You’ve also seen how to key video footage by converting the image to its native colorspace and filtering the compressed channel data to pull a cleaner matte.