mirror of https://github.com/davisking/dlib.git
101 lines
3.9 KiB
C++
101 lines
3.9 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 the first 100 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/gui_widgets.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 the 100 strongest SURF points from the image
|
|
std::vector<surf_point> sp = get_surf_points(img, 100);
|
|
|
|
// create a window to display the input image and the SURF boxes. (Note that
|
|
// you can zoom into the window by holding CTRL and scrolling the mouse wheel)
|
|
image_window my_window(img);
|
|
|
|
// Now lets draw some rectangles on top of the image so we can see where
|
|
// SURF found its points.
|
|
for (unsigned long i = 0; i < sp.size(); ++i)
|
|
{
|
|
// Pull out the info from the SURF point relevant to figuring out
|
|
// where its rotated box should be.
|
|
const unsigned long box_size = static_cast<unsigned long>(sp[i].p.scale*20);
|
|
const double ang = sp[i].angle;
|
|
const point center(sp[i].p.center);
|
|
rectangle rect = centered_rect(center, box_size, box_size);
|
|
|
|
// Rotate the 4 corners of the rectangle
|
|
const point p1 = rotate_point(center, rect.tl_corner(), ang);
|
|
const point p2 = rotate_point(center, rect.tr_corner(), ang);
|
|
const point p3 = rotate_point(center, rect.bl_corner(), ang);
|
|
const point p4 = rotate_point(center, rect.br_corner(), ang);
|
|
|
|
// Draw the sides of the box as red lines
|
|
my_window.add_overlay(image_window::overlay_line(p1, p2, rgb_pixel(255,0,0)));
|
|
my_window.add_overlay(image_window::overlay_line(p1, p3, rgb_pixel(255,0,0)));
|
|
my_window.add_overlay(image_window::overlay_line(p4, p2, rgb_pixel(255,0,0)));
|
|
my_window.add_overlay(image_window::overlay_line(p4, p3, rgb_pixel(255,0,0)));
|
|
|
|
// Draw a line from the center to the top side so we can see how the box is oriented.
|
|
// Also make this line green.
|
|
my_window.add_overlay(image_window::overlay_line(center, (p1+p2)/2, rgb_pixel(0,255,0)));
|
|
}
|
|
|
|
// 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;
|
|
}
|
|
}
|
|
|
|
// ----------------------------------------------------------------------------
|
|
|