Keying - Nuke 101: Professional Compositing and Visual Effects - page 329

This removed all the gray noise in the background. It did, however, produce a gray noise
halo around the girl's head—but that won't be noticeable in the final result, and can be
tweaked by changing the properties in the Dilate and Blur nodes ( FIGURE 7.40 ).
Figure 7.40. Using the garbage matte has cleaned up most of the black area in the
matte.
Spill suppressing with HueCorrect
So you built a little tree to create a better matte. In general, you will make another tree
to create a better fill as well. The fill consists of the RGB channels, so you will remove
anykindofspillyoucanfindintheRGB.Somekeyerstakecareofthat,somedon't—but
even the ones that do handle it don't always give you the same control as a tree built in
Nuke where everything is something you chose.
AgoodnodeforremovingspillistheHueCorrectnode.HueCorrectisanotherveryuseful
tool for color correcting in Nuke. HueCorrect allows for changes according to the hue of
a pixel, mixing together the color weights for that hue.
1. Select Read2 and Shift-click to branch out a HueCorrect node from the Color
toolbox ( FIGURE 7.41 ).
Figure 7.41. The HueCorrect's interface is very similar to that of the
HueKeyer.