// 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 #include #include #include 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 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]); // Now lets use some image functions. First lets blur the image a little. array2d blurred_img; gaussian_blur(img, blurred_img); // Now find the horizontal and vertical gradient images. array2d horz_gradient, vert_gradient; array2d edge_image; sobel_edge_detector(blurred_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 a // window to display them on the screen. (Note that you can zoom into // the window by holding CTRL and scrolling the mouse wheel) image_window my_window(edge_image, "Normal Edge Image"); // We can also easily display the edge_image as a heatmap like so. image_window win_hot(heatmap(edge_image, 255)); // also make a window to display the original image image_window my_window2(img, "Original Image"); // Sometimes you want to get input from the user about which pixels are important // for some task. You can do this easily by trapping user clicks as shown below. // This loop executes every time the user double clicks on some image pixel and it // will terminate once the user closes the window. point p; while (my_window.get_next_double_click(p)) { cout << "User double clicked on pixel: " << p << endl; cout << "edge pixel value at this location is: " << (int)edge_image[p.y()][p.x()] << endl; } // wait until the user closes the windows before we let the program // terminate. win_hot.wait_until_closed(); my_window2.wait_until_closed(); } catch (exception& e) { cout << "exception thrown: " << e.what() << endl; } } // ----------------------------------------------------------------------------