2. vxl example programs

#include <vcl_iostream.h>
#include <vil1/vil1_load.h>
#include <vil1/vil1_save.h>
#include <vepl/vepl_gradient_mag.h>

int main(int argc, char** argv)
{
  // The input image:
  vil1_image in = vil1_load(argv[1]);

  // The filter:
  vil1_image out = vepl_gradient_mag(in);

  // Write output:
  vil1_save(out, argv[2], "pnm");
  vcl_cout << "Written image of type PNM to " << argv[2] << vcl_endl;

  return 0;
}