dlib/examples/surf_ex.cpp

83 lines
3.0 KiB
C++

// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*
This is a simple example illustrating the use of the get_surf_points() function. It
pulls out SURF points from an input image and displays them on the screen as an overlay
on the image.
For a description of the SURF algorithm you should consult the following papers:
This is the original paper which introduced the algorithm:
SURF: Speeded Up Robust Features
By Herbert Bay, Tinne Tuytelaars, and Luc Van Gool
This paper provides a nice detailed overview of how the algorithm works:
Notes on the OpenSURF Library by Christopher Evans
*/
#include <dlib/image_keypoint/draw_surf_points.h>
#include <dlib/image_io.h>
#include <dlib/image_keypoint.h>
#include <fstream>
using namespace std;
using namespace dlib;
// ----------------------------------------------------------------------------
int main(int argc, char** argv)
{
try
{
// make sure the user entered an argument to this program
if (argc != 2)
{
cout << "error, you have to enter a BMP file as an argument to this program" << endl;
return 1;
}
// Here we declare an image object that can store rgb_pixels. Note that in dlib
// there is no explicit image object, just a 2D array and various pixel types.
array2d<rgb_pixel> img;
// Now load the image file into our image. If something is wrong then load_image()
// will throw an exception. Also, if you linked with libpng and libjpeg then
// load_image() can load PNG and JPEG files in addition to BMP files.
load_image(img, argv[1]);
// Get SURF points from the image. Note that get_surf_points() has some optional
// arguments that allow you to control the number of points you get back. Here we
// simply take the default.
std::vector<surf_point> sp = get_surf_points(img);
cout << "number of SURF points found: "<< sp.size() << endl;
if (sp.size() > 0)
{
// A surf_point object contains a lot of information describing each point.
// The most important fields are shown below:
cout << "center of first SURF point: "<< sp[0].p.center << endl;
cout << "pyramid scale: " << sp[0].p.scale << endl;
cout << "SURF descriptor: \n" << sp[0].des << endl;
}
// Create a window to display the input image and the SURF points. (Note that
// you can zoom into the window by holding CTRL and scrolling the mouse wheel)
image_window my_window(img);
draw_surf_points(my_window, sp);
// wait until the user closes the window before we let the program
// terminate.
my_window.wait_until_closed();
}
catch (exception& e)
{
cout << "exception thrown: " << e.what() << endl;
}
}
// ----------------------------------------------------------------------------