tutorial.cpp

this a image processing program

/*-----------------------------------------------------------------------

  File        : tutorial.cpp

  Description : View the color profile of an image, along the X-axis

  Copyright  : David Tschumperle - http://www.greyc.ensicaen.fr/~dtschump/

  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 library file and use its main namespace
#include "../CImg.h"
using namespace cimg_library;

// Begin the program
int main(int argc,char **argv) {

  // Define program usage and read command line parameters
  //-------------------------------------------------------

  // Display program usage, when invoked from the command line with option '-h'.
  cimg_usage("View the color profile of an image along the X axis");

  // Read image filename from the command line (or set it to "img/parrot_original.ppm" if option '-i' is not provided).
  const char* file_i = cimg_option("-i","img/parrot_original.ppm","Input image");

  // Read pre-blurring variance from the command line (or set it to 1.0 if option '-blur' is not provided).
  const double sigma = cimg_option("-blur",1.0,"Variance of gaussian pre-blurring");

  // Init variables
  //----------------

  // Load an image, transform it to a color image (if necessary) and blur it with a standart deviation sigma.
  const CImg<unsigned char> image = CImg<>(file_i).normalize(0,255).blur((float)sigma).resize(-100,-100,1,3);

  // Create two display window, one for the image, the other for the color profile.
  CImgDisplay
    main_disp(image,"Color image (Try to move mouse pointer over)",0),
    draw_disp(500,400,"Color profile of the X-axis",0);

  // Define colors used to plot the profile, and a hatch to draw the line
  unsigned long hatch=0xF0F0F0F0;
  const unsigned char
    red  [3] = {255,  0,  0},
    green[3] = {  0,255,  0},
    blue [3] = {  0,  0,255},
    black[3] = {0,    0,  0};

  // Enter event loop. This loop ends when one of the two display window is closed.
  while (!main_disp.is_closed && !draw_disp.is_closed) {

    // Handle display window resizing (if any)
    if (main_disp.is_resized) main_disp.resize().display(image);
    draw_disp.resize();

    if (main_disp.mouse_x>=0 && main_disp.mouse_y>=0) { // Mouse pointer is over the image

      const int
	xm = main_disp.mouse_x,                     // X-coordinate of the mouse pointer over the image
	ym = main_disp.mouse_y,                     // Y-coordinate of the mouse pointer over the image
	xl = xm*draw_disp.dimx()/main_disp.dimx(),  // Corresponding X-coordinate of the hatched line
	x = xm*image.dimx()/main_disp.dimx(),       // Corresponding X-coordinate of the pointed pixel in the image
	y = ym*image.dimy()/main_disp.dimy();       // Corresponding Y-coordinate of the pointex pixel in the image

      // Retrieve color component values at pixel (x,y)
      const unsigned int
	val_red   = image(x,y,0),
	val_green = image(x,y,1),
	val_blue  = image(x,y,2);

      // Create and display the image of the intensity profile
      CImg<unsigned char>(draw_disp.dimx(),draw_disp.dimy(),1,3,255).
        draw_grid(-50*100.0f/image.dimx(),-50*100.0f/256,0,0,black,0xCCCCCCCC,0xCCCCCCCC,false,true,0.2f).
        draw_axis(0,image.dimx()-1,255,0,black).
        draw_graph(image.get_shared_line(y,0,0),red,0,255,0).
        draw_graph(image.get_shared_line(y,0,1),green,0,255,0).
        draw_graph(image.get_shared_line(y,0,2),blue,0,255,0).
        draw_text(30,5,black,0,11,1,"Pixel (%d,%d)={%d %d %d}",main_disp.mouse_x,main_disp.mouse_y,val_red,val_green,val_blue).
        draw_line(xl,0,xl,draw_disp.dimy()-1,black,hatch=cimg::rol(hatch),0.5).
        display(draw_disp);
    } else
      // else display a text in the profile display window.
      CImg<unsigned char>(draw_disp.dimx(),draw_disp.dimy()).fill(255).
        draw_text("Mouse pointer is outside the image",draw_disp.dimx()/2-110,draw_disp.dimy()/2-5,black).display(draw_disp);

    // Temporize event loop
    cimg::wait(20);
  }

  return 0;
}