dlib/examples/image_ex.cpp

88 lines
2.9 KiB
C++

// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*
This is an example illustrating the use of the GUI API as well as some
aspects of image manipulation from the dlib C++ Library.
This is a pretty simple example. It takes a BMP file on the command line
and opens it up, runs a simple edge detection algorithm on it, and
displays the results on the screen.
*/
#include "dlib/gui_widgets.h"
#include "dlib/image_io.h"
#include "dlib/image_transforms.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 open the image file. Note that when you open a binary file with
// the C++ ifstream you must supply the ios::binary flag.
ifstream fin(argv[1],ios::binary);
if (!fin)
{
cout << "error, can't find " << argv[1] << 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>::kernel_1a img;
// now load the bmp file into our image. If the file isn't really a BMP
// or is corrupted then load_bmp() will throw an exception.
load_bmp(img, fin);
// Now lets use some image functions. This example is going to perform
// simple edge detection on the image. First lets find the horizontal and
// vertical gradient images.
array2d<short>::kernel_1a horz_gradient, vert_gradient;
array2d<unsigned char>::kernel_1a edge_image;
sobel_edge_detector(img,horz_gradient, vert_gradient);
// now we do the non-maximum edge suppression step so that our edges are nice and thin
suppress_non_maximum_edges(horz_gradient, vert_gradient, edge_image);
// Now we would like to see what our images look like. So lets use our
// window to display them on the screen.
// create a window to display the edge image
image_window my_window(edge_image);
// also make a window to display the original image
image_window my_window2(img);
// wait until the user closes both windows before we let the program
// terminate.
my_window.wait_until_closed();
my_window2.wait_until_closed();
}
catch (exception& e)
{
cout << "exception thrown: " << e.what() << endl;
}
}
// ----------------------------------------------------------------------------