Apple MA434Z/A User Manual - Page 714

• decolor all: When this mode is selected, the value parameter appears at the bottom of the Parameters tab. Adjusting the value parameter shrinks or expands the polyhedron between zone 4 (all foreground) and zone 3 (foreground plus spill suppress). Positive values expand the shell, effectively shifting across the entire image more color from the foreground into the suppressed area. Negative values contract the shell, thereby slipping more values away from the suppressed area into the foreground area. Because the shells cannot intersect, if you shrink the shell too much, you also crush the smaller interior shells, causing all values to shift toward the background. • spill sponge: Affects the color of the foreground, but not the matte. This operation suppresses the color you pick. "spill sponge" is usually used on spill areas that are known to be opaque-for example, blue spill on the face or body. If the change is too drastic, supplement or replace the operation with fine tuning-spillSponge adjustment. • matte sponge: Used to restore foreground areas lost during spill suppression. "matte sponge" only affects the alpha channel. currentOp Each operator you use to perform a scrub operation is maintained separately in memory. The history of all the operations you've performed within the Primatte node is accessible using the currentOp slider. Moving the slider to the left returns the you to any previous scrub operation you've performed, allowing you to re-adjust or delete it. To see which operation you've selected, look at the name that appears at the top of the color control that appears below the slider. delete op Click "delete op" to delete the operation that's currently selected in the currentOp parameter. Color Control (initially set to "center") This control isn't dedicated to any one parameter. Instead, the color control lets you assign a color to whichever operator you've clicked in the Primatte node. Additionally, this control displays the color that's currently assigned to whichever operator you've selected using the currentOp slider. When you first assign a Primatte node to an image, this control is set to "center." It is the first operation you use when you begin keying with the Primatte node. Scrub pixels in the background of the image to be keyed to define the starting range of color to be keyed out. Doing so determines the center of the 3D polyhedron (described above), and is therefore extremely important. When the center operation is selected, the multiplier parameter appears at the bottom of the Parameters tab. 714 Chapter 24 Keying