Keying - Nuke 101: Professional Compositing and Visual Effects - page 301

green- and bluescreen elements. So instead of having one blue or green shade,
you have many. The IBK, which consists of two nodes—IBKColour and IBKG-
izmo—creates a color image representing all those different screen colors (but
withouttheforegroundelement),andthenusesthattokeyinsteadofasinglecolor
( FIGURE 7.3 ) .
Figure 7.3. A basic IBK tree that includes the two IBK nodes.
• Keyer: Thisisabasickeyer,mainlyusedforluminance-basedkeyingor luma key-
ing ( FIGURE 7.4 ) .
Figure 7.4. The Keyer node's Properties panel.