7.4 Edge Detection
In most cases, major variations in intensity in an image correspond to edges of objects. You can often extract objects in an image by detecting these variations through a process called segmentation. In GIMP, you can do this using the edge detection tools.
The Principles of Edge Detection
Technically, the edges in an image are any areas where the intensity presents a strong local variation. Edge detection is a fundamental part of extracting information from an image during preprocessing. Often, the discovered edges are then fed to a shape recognition system. Shape recognition has applications in robotics, medical image analysis, video surveillance, and other fields.
Figure 7-64. After a strong Gaussian blur
Figure 7-65. The Edge-Detect ...