Can you blur within a vignette in the secondaries room?

Question

I would like to blur a small product label in a clip. Is there a way in Color to create a vignette in the secondaries room, use tracking to make it follow the limited movement of the label, and blur only what is inside the vignette, that is, blur the label?
It seems pretty straighforward to use the color correctors to change whatever is inside the vignette, or change saturation, but I cannot figure out how to attach a blur filter to the vignette. Or is there a way in the Color FX room to use a blur filter but affect only a small portion of the image, well, a way besides using the HSL keying node. I did try that but it didn't really work.
Any advice much appreciated,
Jim

Answer 1

OK, thanks for pointing me in the right direction jPo. After I thought about it for a while, I figured I should probably use Shake . . . but I hate roto so much! I would have had to do some animating of the rotoshape. I actually ended up doing it within Final Cut. Put a copy of the clip on top of the main video track, blurred the whole thing, and knocked out everything but the label (with some room for its movement) with a garbage matte. Kind of an inelegant way to do it, but that accomplished what I needed for the most part, and it was fairly painless.
Jim