Apple Shake 4 - Manual (Page 407)

Chapter 15 Image Processing Basics 407
Nodes that modify image resolution also take advantage of the Shake Infinite
Workspace. For example, if you apply a Crop node to a 20,000 x 20,000-pixel image,
Shake calculates only the area of the image specified in the node. This is true even if
you employ other nodes prior to the Crop. The Infinite Workspace allows Shake to limit
the processing power needed by your script, because only the contents of the Crop
window are calculated. This makes Shake ideally suited for high-resolution functions
such as scrolling a large background image under lower-resolution foreground
elements.
When working with the Infinite Workspace, bear in mind the following:
• You do not need to crop a small image before it is composited with a larger image
when you are panning the image. Simply read in your image, apply the pan, and
composite it over or under the larger image.
• The Blur node gives you the option to blur pixels outside of the frame using the
spread parameter. When set to 0, only pixels inside the frame are considered. When
set to 1, outside pixels are calculated into the blur as well. When you read in an
image and then blur the image, set the spread to 0. Otherwise, black ringing occurs
around the edge because Shake adds the empty black region beyond the image
border into its blur calculation. If you read in the image, scale it up, and then blur,
you should set spread to 1, since there are now non-black pixels outside of the
frame.
• If you transform an object, apply a color correction, then transform the object back
to its original state, the entire image retains the result of the color correction, not just
the portion that was in the frame when you applied the color correction.
Clipped Images
If an image is clipped, it is usually because a Crop node has been applied, or because
you have applied a Blur with a spread set to 0, which is including black outside the
image area. Set spread to 1 in the Blur node’s parameters.
spread = 1 spread = 0