Building and running a few sample applications is a good way to test that OpenCV is correctly set up. At the same time, we can practice using Eclipse.
Let's start by launching Eclipse. The Eclipse launcher should be located at
<eclipse>/Eclipse.app (Mac), or
<eclipse>/eclipse (Linux). Run it.
We should see a window called Workspace Launcher, which asks us to select a workspace. A workspace is the root directory for a set of related Eclipse projects. Enter any location you choose.
We can return to Workspace Launcher anytime via the menu: File | Switch Workspace | Other….