1Before anything else, let's look at some example programs.
2
3@section Gradients
4The image processing equivalent of "Hello world":
5@example
6
7#include <vcl_iostream.h>
8#include <vil/vil_load.h>
9#include <vil/vil_save.h>
10#include <vepl/vepl_gradient_mag.h>
11
12int main(int argc, char** argv)
13@{
14  // The input image:
15  vil_image_view<unsigned char> in = vil_load(argv[1]);
16
17  // The filter:
18  vil_image_view<unsigned char> out = vepl_gradient_mag(in);
19
20  // Write output:
21  vil_save(out, argv[2]);
22  vcl_cout << "Written the gradrient image to " << argv[2] << vcl_endl;
23
24  return 0;
25@}
26@end example
27This example takes one grey-level image, and creates a second whose pixel values are the
28gradient magnitudes of the first.
29