2011

NOTE You can use the following hotkeys to quickly select a manipulator; press
M to select the Input manipulator, press comma (,) to select the Effect manipulator,
or press period (.) to select the Output manipulator.
Cropping and Filtering the Output
The Crop allows you to change the size of an image. Crop manipulators are
visible when selecting the Output tab—see
Crop Tool on page 410.
The filtering processes attempt to smooth the transformed pixels. When an
image is being warped, there is a need to interpolate the old pixel map to a
new one. This requires some form of image reconstruction and a number of
resampling methods can be used.
All Warp tools have common filtering parameters:
DescriptionFilter
A box filter and the fastest way to resample an image since it only
samples a single pixel of the input image to determine the value of a
given pixel in the result image. Produces significant amount of aliasing.
Nearest
A separable triangular filter that takes into account more area when
resampling.
Bilinear (de-
fault)
Considered as one of the best magnification filters for images; has a
good balance between ringing and sharpness.
Mitchell
Good magnification and magnification filter with no ringing, but intro-
duces noticeable softness to the result image.
Gaussian
Offers better sharpness than the Gaussian one, but at the expense of
ringing. Similar to the sinc filter, but with better isotropic qualities, less
ringing, and same sharpening and anti-aliasing.
Jinc 2
Offers better sharpness than the Gaussian and Jinc2 filters but at the
expense of even more ringing. Similar to the Lanczos filter, but with
Jinc 3
482 | Chapter 19 Warping