Graphics Reference
In-Depth Information
Figure 11.24.
The result of the sharpness operation with the 5 × 5 blurred image (
T
= 0, left), the original image
(
T
= 1, middle), and the sharpened image (
T
= 5, right).
This is a special case of unsharp masking, a standard image manipulation
technique to sharpen photographic images for printing. The general technique
uses a blur filter of adjustable radius and an adjustable blend; this example
uses radius 1 and a limited adjustable blend.
Blending Two Different Images
The two-image manipulations in the sections above have really been about
creating effects in a single image, using another reference image as a tool.
However, sometimes you have two images that each have content, and you
Figure 11.25.
Two sample images we will use to illustrate blending: Washington cherry
blossoms (left) and Xidi, an ancient Hong village in Anhui province, China (right).
