LinuxQuestions.org - design a GUI interface with c++

Regarding to CImg, I download the CImg_1.6.0_rolling140915.zip and moved the header to the /usr/include directory. I took one of the example and I compiled it with g++ and I am getting errors as described below;

This is the code;

/*
#
# File : tutorial.cpp
# ( C++ source file )
#
# Description : View the color profile of an image, along the X-axis.
# This file is a part of the CImg Library project.
# ( http://cimg.sourceforge.net )
#
# Copyright : David Tschumperle
# ( http://tschumperle.users.greyc.fr/ )
#
# License : CeCILL v2.0
# ( http://www.cecill.info/licences/Lice...ILL_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 library file and use its main namespace
#include <CImg/CImg.h>
using namespace cimg_library;

#ifndef cimg_imagepath
#define cimg_imagepath "img/"
#endif

// Main procedure
//----------------
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",cimg_imagepath "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 the standard 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 vertical line
unsigned int hatch = 0xF0F0F0F0;
const unsigned char
red[] = { 255,0,0 },
green[] = { 0,255,0 },
blue [] = { 0,0,255 },
black[] = { 0,0,0 };

// Enter event loop. This loop ends when one of the two display window is closed or when the keys 'ESC' or 'Q' are pressed.
while (!main_disp.is_closed() && !draw_disp.is_closed() &&
!main_disp.is_keyESC() && !draw_disp.is_keyESC() && !main_disp.is_keyQ() && !draw_disp.is_keyQ()) {

// 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.width()/main_disp.width(), // Corresponding X-coordinate of the hatched line
x = xm*image.width()/main_disp.width(), // Corresponding X-coordinate of the pointed pixel in the image
y = ym*image.height()/main_disp.height(); // 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.width(),draw_disp.height(),1,3,255).
draw_grid(-50*100.0f/image.width(),-50*100.0f/256,0,0,false,true,black,0.2f,0xCCCCCCCC,0xCCCCCCCC).
draw_axes(0,image.width()-1.0f,255.0f,0.0f,black).
draw_graph(image.get_shared_row(y,0,0),red,1,1,0,255,1).
draw_graph(image.get_shared_row(y,0,1),green,1,1,0,255,1).
draw_graph(image.get_shared_row(y,0,2),blue,1,1,0,255,1).
draw_text(30,5,"Pixel (%d,%d)={%d %d %d}",black,0,1,16,
main_disp.mouse_x(),main_disp.mouse_y(),val_red,val_green,val_blue).
draw_line(xl,0,xl,draw_disp.height()-1,black,0.5f,hatch=cimg::rol(hatch)).
display(draw_disp);
} else
// else display a text in the profile display window.
CImg<unsigned char>(draw_disp.width(),draw_disp.height()).fill(255).
draw_text(draw_disp.width()/2-130,draw_disp.height()/2-5,"Mouse pointer is outside the image",black,0,1,16).display(draw_disp);

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

return 0;
}

and bellow is the error message;
[root@localhost src]# g++ graphic5.cpp
/tmp/ccZQ8o5F.o: In function `cimg_library::cimg::Mutex_info::trylock(unsigned int)':
graphic5.cpp:(.text._ZN12cimg_library4cimg10Mutex_info7trylockEj[cimg_library::cimg::Mutex_info::trylock(unsigned int)]+0x19): undefined reference to `pthread_mutex_trylock'
/tmp/ccZQ8o5F.o: In function `cimg_library::cimg::X11_info::X11_info()':
graphic5.cpp:(.text._ZN12cimg_library4cimg8X11_infoC1Ev[cimg_library::cimg::X11_info::X11_info()]+0x52): undefined reference to `XInitThreads'
/tmp/ccZQ8o5F.o: In function `cimg_library::cimg::X11_info::~X11_info()':
graphic5.cpp:(.text._ZN12cimg_library4cimg8X11_infoD1Ev[cimg_library::cimg::X11_info::~X11_info()]+0x1c): undefined reference to `pthread_cancel'
/tmp/ccZQ8o5F.o: In function `void cimg_library::CImgDisplay::_resize<unsigned char>(unsigned char, unsigned int, unsigned int, bool)':

Am I missing more library?