2011

Table Of Contents
To:Use:
Specify a minimum of blur to apply in any direction. This is useful to
minimize aliasing artifacts that might occur when performing blurs that
exhibits a high degree of directionality.
Min Radius
Specify how the input image should be extended outside its region of
definition (ROD). This is important for two reasons. First, the convolution
Tiling X and
Y
kernel of the Blur tool might need to access source pixels outside the
ROD to produce pixel falling inside the source ROD. Secondly, the Blur
tool allows the output image to be uncropped arbitrarily. The supported
tiling modes are Edge (default), Transparent, Repeat, and Mirror.
Crop (and uncrop) the image produced by the Blur tool. The cropping
controls work exactly like the ones found in the Crop tool with the ex-
Crop
ception of the addition of an Auto Crop mode. When in Auto Crop
mode, the Left, Right, Bottom and Top controls are greyed out. Instead
the output ROD is computed automatically based on the following as-
sumptions; only the parameters of the Gaussian Blur are used to determ-
ine the output ROD. This includes the Gaussian X radius, Y radius and
Rotation; the Input ROD is enlarged by an amount proportional to the
rotated X and Y radius. It is enlarged sufficiently so that the profile of
the Gaussian filter drops sufficiently close to zero at the boundary of
the enlarged kernel. This behavior is especially useful when the X and
Y Tilling modes are set to Transparent. The supported crop modes are
Relative (default), Window, Absolute, and Auto Crop.
Lens Blur Tool
The Lens Blur tool allows you to simulate rack defocus and add photographic
effects to 3D rendered scenes or live footage. You can also create lens flares,
streak lines, and halos around bright lights and reflections.
400 | Chapter 17 Image Processing Tools