Apple Shake 4 - Manual (Page 463)

Chapter 16 Compositing With Layer Nodes 463
Interlace
This node interlaces two images. You can control field dominance, whether the input
images are themselves separate field images (for example, half Y resolution), or if the
fields are extracted from every other line. For information on the Interlace node, see
“
Interlace ” on page 205.
ISub
The ISub image math node subtracts one image from another. The strength of the
second image can be raised and lowered with the percent parameter. If you want to
detect the difference between two images, use ISubA instead, because it takes the
absolute value of the difference.
Parameters
This node displays the following controls in the Parameters tab:
clipMode
Toggles between the foreground (0) or the background (1) image to set the output
resolution.
percent
A built-in fade parameter. This is the amount of the second image that is taken into
consideration. Full strength is 100. If set to 50, the added amount is reduced by 50
percent.
ISubA
The ISubA node is identical to ISub, except that it takes the absolute value of the result.
This is to see if similar images are different by subtracting one image from another. If
the second image is brighter, ISub does not reveal anything, but ISubA does (for
example, .5 - .8 = -.3, absolute value of -.3 = .3).
Parameters
This node displays the following controls in the Parameters tab:
clipMode
Toggles between the foreground (0) or the background (1) image to set the output
resolution.
percent
A built-in fade parameter. This is the amount of the second image that is taken into
consideration. Full strength is 100. If set to 50, the added amount is reduced by 50
percent.