Squashed 'third_party/cimg/' content from commit 4b66369
Change-Id: I7454d9107a08dba899fd4659731733049165ae0a
git-subtree-dir: third_party/cimg
git-subtree-split: 4b66369ab4e34a46119d6c43e9adce061bb40f4b
diff --git a/examples/hough_transform2d.cpp b/examples/hough_transform2d.cpp
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+/*
+ #
+ # File : hough_transform2d.cpp
+ # ( C++ source file )
+ #
+ # Description : Implementation of the Hough transform.
+ # This file is a part of the CImg Library project.
+ # ( http://cimg.eu )
+ #
+ # Copyright : David Tschumperle
+ # ( http://tschumperle.users.greyc.fr/ )
+ #
+ # License : CeCILL v2.0
+ # ( http://www.cecill.info/licences/Licence_CeCILL_V2-en.html )
+ #
+ # This software is governed by the CeCILL license under French law and
+ # abiding by the rules of distribution of free software. You can use,
+ # modify and/ or redistribute the software under the terms of the CeCILL
+ # license as circulated by CEA, CNRS and INRIA at the following URL
+ # "http://www.cecill.info".
+ #
+ # As a counterpart to the access to the source code and rights to copy,
+ # modify and redistribute granted by the license, users are provided only
+ # with a limited warranty and the software's author, the holder of the
+ # economic rights, and the successive licensors have only limited
+ # liability.
+ #
+ # In this respect, the user's attention is drawn to the risks associated
+ # with loading, using, modifying and/or developing or reproducing the
+ # software by the user in light of its specific status of free software,
+ # that may mean that it is complicated to manipulate, and that also
+ # therefore means that it is reserved for developers and experienced
+ # professionals having in-depth computer knowledge. Users are therefore
+ # encouraged to load and test the software's suitability as regards their
+ # requirements in conditions enabling the security of their systems and/or
+ # data to be ensured and, more generally, to use and operate it in the
+ # same conditions as regards security.
+ #
+ # The fact that you are presently reading this means that you have had
+ # knowledge of the CeCILL license and that you accept its terms.
+ #
+*/
+
+#include "CImg.h"
+using namespace cimg_library;
+#ifndef cimg_imagepath
+#define cimg_imagepath "img/"
+#endif
+
+// Main procedure
+//----------------
+int main(int argc,char **argv) {
+ cimg_usage("Illustration of the Hough transform");
+ CImg<unsigned char> src(cimg_option("-i",cimg_imagepath "parrot.ppm","Input image"));
+ CImg<> vote(500,400,1,1,0), img = src.get_norm().normalize(0,255).resize(-100,-100,1,2,2);
+
+ CImgDisplay disp(src,"Image"), dispvote(vote,"Hough Transform");
+ const unsigned char col1[3]={255,255,255}, col2[3]={0,0,0};
+ const double
+ alpha = cimg_option("-a",1.5,"Gradient smoothing"),
+ sigma = cimg_option("-s",0.5,"Hough Transform smoothing"),
+ rhomax = std::sqrt((double)(img.width()*img.width() + img.height()*img.height()))/2,
+ thetamax = 2*cimg::PI;
+
+ if (cimg::dialog(cimg::basename(argv[0]),
+ "Instructions : \n"
+ "----------------\n\n"
+ "(1) When clicking on the color image, all lines crossing the selected point\n"
+ "will be voted in the Hough buffer.\n\n"
+ "(2) When clicking on the Hough buffer, the corresponding line is drawn\n"
+ "on the color image.\n\n"
+ "(3) When pressing the space bar, lines in the color image are detected from the\n"
+ "image gradients through votes in the Hough buffer.\n\n"
+ "Note that a logarithmic scaling is performed for displayin the vote image.\n"
+ "See also the available options (option '-h')\n","Start !","Quit",0,0,0,0,
+ src.get_resize(100,100,1,3),true)) std::exit(0);
+
+ while (!disp.is_closed() && !dispvote.is_closed() &&
+ !disp.is_keyQ() && !dispvote.is_keyQ() && !disp.is_keyESC() && !dispvote.is_keyESC()) {
+
+ CImgDisplay::wait(disp,dispvote);
+
+ // When pressing space bar, the vote is performed from the image gradients.
+ if (dispvote.is_keySPACE() || disp.is_keySPACE()) {
+ CImgList<> grad = img.get_gradient();
+ cimglist_for(grad,l) grad[l].blur((float)alpha);
+ vote.fill(0);
+ cimg_forXY(img,x,y) {
+ const double
+ X = (double)x - img.width()/2,
+ Y = (double)y - img.height()/2,
+ gx = grad[0](x,y),
+ gy = grad[1](x,y);
+ double
+ theta = std::atan2(gy,gx),
+ rho = std::sqrt(X*X + Y*Y)*std::cos(std::atan2(Y,X) - theta);
+ if (rho<0) { rho=-rho; theta+=cimg::PI; }
+ theta = cimg::mod(theta,thetamax);
+ vote((int)(theta*dispvote.width()/thetamax),(int)(rho*dispvote.height()/rhomax))+=
+ (float)std::sqrt(gx*gx + gy*gy);
+ }
+ vote.blur((float)sigma);
+ CImg<> vote2(vote); cimg_forXY(vote2,x,y) vote2(x,y) = (float)std::log(1 + vote(x,y)); vote2.display(dispvote);
+ }
+
+ // When clicking on the vote window.
+ if (dispvote.button()) {
+ const double
+ rho = dispvote.mouse_y()*rhomax/dispvote.height(),
+ theta = dispvote.mouse_x()*thetamax/dispvote.width(),
+ x = img.width()/2 + rho*std::cos(theta),
+ y = img.height()/2 + rho*std::sin(theta);
+ const int
+ x0 = (int)(x + 1000*std::sin(theta)),
+ y0 = (int)(y - 1000*std::cos(theta)),
+ x1 = (int)(x - 1000*std::sin(theta)),
+ y1 = (int)(y + 1000*std::cos(theta));
+ CImg<unsigned char>(src).
+ draw_line(x0,y0,x1,y1,col1,1.0f,0xF0F0F0F0).draw_line(x0,y0,x1,y1,col2,1.0f,0x0F0F0F0F).
+ draw_line(x0 + 1,y0,x1 + 1,y1,col1,1.0f,0xF0F0F0F0).draw_line(x0 + 1,y0,x1 + 1,y1,col2,1.0f,0x0F0F0F0F).
+ draw_line(x0,y0 + 1,x1,y1 + 1,col1,1.0f,0xF0F0F0F0).draw_line(x0,y0 + 1,x1,y1 + 1,col2,1.0f,0x0F0F0F0F).
+ display(disp);
+ }
+
+ // When clicking on the image.
+ if (disp.button() && disp.mouse_x()>=0) {
+ const double
+ x0 = (double)disp.mouse_x() - disp.width()/2,
+ y0 = (double)disp.mouse_y() - disp.height()/2,
+ rho0 = std::sqrt(x0*x0 + y0*y0),
+ theta0 = std::atan2(y0,x0);
+
+ for (double t=0; t<thetamax; t+=0.001) {
+ double theta = t, rho = rho0*std::cos(theta0 - t);
+ if (rho<0) { rho=-rho; theta=cimg::mod(theta + cimg::PI,thetamax); }
+ vote((int)(theta*vote.width()/thetamax),(int)(rho*vote.height()/rhomax))+=1;
+ }
+ CImg<> vote2(vote); cimg_forXY(vote2,x,y) vote2(x,y) = (float)std::log(1 + vote(x,y)); vote2.display(dispvote);
+ }
+ dispvote.resize(dispvote);
+ disp.resize(disp);
+ }
+
+ std::exit(0);
+ return 0;
+}