Apple Shake 4 - Manual (Page 863)

Chapter 28 Filters 863
To further maximize the quality of transforms, some nodes in Shake (such as CornerPin)
let you use separate filter operations for horizontal and vertical transforms. Keep in mind
that the default filter option uses mitchell for scaling up, and sinc for scaling down.
Applying Separate Filters to X and Y Dimensions
If a node does not already have separate filtering options for X and Y transforms (such
as the Resize node), you can set up independent filtering for each dimension in two
steps. For example, apply one Resize node, set the filter parameter to the desired filter
method, then adjust the xSize parameter while leaving the ySize parameter
untouched. Next, apply a second Resize node immediately after the first. Set a
different filter method, then adjust its ySize parameter. Because both nodes
concatenate, the result is computationally and qualitatively efficient.
Note: The subpixel parameter in the Resize node affects the way fractional resize is
performed. If your resize value is not an integer (for example, 512 zooming to 1024 is
an integer by a factor of 2; zooming 512 to 1023 is not an integer, because it is a factor
of 1.998), you have subpixel sampling. For Resize, if the new width or height is not an
integer (either because it was set that way, or because of a proxy scale), you have a
choice to snap to the closest integer (0 = subpixel off ) or generate transparent pixels
for the last row and column (1 = subpixel on).
Filter Description
box Computationally fast, and gives a “boxy” look. Default size is 1 x 1.
default By default, mitchell is used to resize up, and sinc to resize down.
dirac Dirac and impulse are the same. Default size is 0 x 0.
gauss Gaussian lacks in sharpness, but is good with ringing and aliasing.
Default size is 5 x 5.
impulse Fast but lower quality. Default size is 0 x 0.
lanczos Similar to the sinc filter, but with less sharpness and ringing.
Default size is 6 x 6.
mitchell This is the default filter when scaling up. A good balance between
sharpness and ringing, and so a good choice for scaling up. Default
size is 4 x 4. This is also known as a high-quality Catmull-Rom filter.
quad Like triangle, but more blur with fewer artifacts. Default size is 3 x 3.
sinc This is the default filter when scaling down. Keeps small details
when scaling down with good aliasing. Ringing problems make it a
questionable choice for scaling up. Default size is 4 x 4. It can also
deliver negative values, which can be interesting when working in
float/channel bit depth.
triangle Not highest quality, but fine for displaying a scaled image on your
screen. Default size is 2 x 2.