IceMan Reference Guide 
Interpolate between the operand image and another image, using a third image as the interpolating parameter. Interpolation is performed pixelwise.
The result is the maximum of the operand image a or the linear interpolation of a and b. If t is zero, the result will be t. If t is one, the result will be the larger of a and b. For values of t between 0 and 1 the return value will be a the maximum of a or a linear interpolation of a and b.
Normalize to values between 0 and 1. The range image is typically returned by a call to Range().
Clamp values in an image to lie in the interval (min, max).
Pixar Animation Studios
