2011

Table Of Contents
The Front input image is despilled by the Spill & Blend tool node. The result
is sent to the Result node (an instance of the Set Alpha tool) to become the
RGB channels of the RGBA Output Image output.
The Front input image is processed first by the Screen Degrain tool node, then
by the Master Keyer matte generator. The resulting matte is then sent to the
Cleanup Alpha node, then to the Edge node, and that result to the Garbage
Mask node. The output of the Garbage Mask node is sent to the input of the
Result node to become the alpha channel of the RGBA Output Image output,
to the Comp tool as the matte input, and is also outputted directly as the A
Output Image.
The Back input image is sent to the Back input of the Comp tool node (an
instance of the Blend & Comp tool). The Comp tool node provides a composite
of the spill-suppressed front over the back, through the processed matte, both
as a user convenience, and also as output on the Comp Output Image output.
Workflow
The following sequence of actions is a recommended workflow for keying an
image with the Keyer supertool. You may not need to complete all the
procedures. You may also revisit procedures as you develop the key.
Generate and refine a matte using the Master Keyer matte generator
controls.
Create any necessary patches to remove unwanted gray areas from the
matte.
Refine the matte using the Edge and Cleanup Alpha tools.
If the image is grainy, apply the Screen Degrain algorithm.
Remove any color spill.
Improve the blend between the front and back images.
524 | Chapter 22 Pulling Keys and Creating Mattes