Apple Shake 4 - Manual (Page 121)

Chapter 3 Adding Media, Retiming, and Remastering 121
• AlwaysInterpolate: With AlwaysInterpolate turned off, the final result of a retiming
operation is a mix of original, unprocessed frames, and interpolated frames. For
example, setting the speed to 0.5 to slow an image sequence down by 50 percent
results in an alternating series of original frames and interpolated frames. In cases
where there is a significant visual difference (softening, for example) between the
unprocessed and reprocessed frames resulting from a retiming operation, the image
sequence may appear to flicker. Turning on AlwaysInterpolate forces Shake to
process every single frame in a retimed sequence, resulting in a series of frames with
consistent visual quality.
If the Motion parameter is set to Best, three additional parameters become available:
• BackwardFlow: Turning on BackwardFlow evaluates the flow of images in both
directions in order to generate interpolated in-between frames. This mode is usually
visually superior, but significantly slower.
• FlowSmoothness: Higher or lower values may improve the quality of interpolated
frames, depending on the shape of the subject in the image.
• Use low values to improve the quality of subjects in the frame that change shape,
like a person or animal that’s running or jumping.
• Use high values to improve the quality of static objects that don’t change shape,
such as trees, buildings, or cars.
• FlowPrecision: This is the last parameter you should adjust, after obtaining as much
quality as possible with all of the above settings. Increasing the value of this
parameter increases the overall precision of the Adaptive retiming operation by
increasing the resolution at which the optical flow is estimated. A value of 0 is fine for
most situations.