Can I use mask tracking to blur my background?

Question

There is a help video " How to blur a moving face" at How to blur a moving face with masking and tracking | Adobe Premiere Pro CC tutorials  I need to do the opposite. I want the background of a "talking head" video to be blurred and the speaker to be in focus. Is this possible with Premiere?

Answer 1

You don't actually need two video layers, because you can just apply a masked blur to a clip, then *invert* the mask so that everything *outside* the mask is blurred, and everything inside the mask is unaffected. Here are the steps in detail:
1) apply the Blur filter (whichever one you want) to the clip.
2) In the Effects Controls pane, turn the disclosure triangle for the Blur filter and click one of the mask buttons (the oval is probably best for this situation). Drag and resize the mask so it covers the person's face. Feather it as needed (probably not very much in this situation, or you'll get a weird halo-like effect).
3) Back in the Effects Controls pane, under the the Blur filter controls, you'll now see a new option: "Mask (1)". Open those controls and check off "Inverted," so that when you apply the blur, it will apply to the area *outside* the mask, instead of the inside.
4) Turn the Blurriness up until you get the look you want.
5) (You can do this earlier, if you want) - but you have to track the mask so it moves with the person who's moving. To do this, start at the first frame of video. Make sure the mask fits well over the person at that frame. Then click the "Track selected mask forward" button (it looks like a regular triangular play button). It'll step through all the frames and adjust the mask on each frame. If it loses the person, just stop on that frame, adjust the mask, and track forward from there.