Visual Servoing Platform  version 3.5.1 under development (2022-07-05)

Tracking of Surf key-points.

* ViSP, open source Visual Servoing Platform software.
* Copyright (C) 2005 - 2019 by Inria. All rights reserved.
* This software is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* See the file LICENSE.txt at the root directory of this source
* distribution for additional information about the GNU GPL.
* For using ViSP with software that can not be combined with the GNU
* GPL, please contact Inria about acquiring a ViSP Professional
* Edition License.
* See for more information.
* This software was developed at:
* Inria Rennes - Bretagne Atlantique
* Campus Universitaire de Beaulieu
* 35042 Rennes Cedex
* France
* If you have questions regarding the use of this file, please contact
* Inria at
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* Description:
* Tracking of Surf key points.
* Authors:
* Nicolas Melchior
* Fabien Spindler
#include <iomanip>
#include <sstream>
#include <stdio.h>
#include <stdlib.h>
#include <visp3/core/vpConfig.h>
#include <visp3/core/vpDebug.h>
#if ((defined(VISP_HAVE_X11) || defined(VISP_HAVE_GTK) || defined(VISP_HAVE_GDI)) && \
#include <visp3/core/vpImage.h>
#include <visp3/core/vpImagePoint.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/io/vpParseArgv.h>
// List of allowed command line options
#define GETOPTARGS "cdi:h"
void usage(const char *name, const char *badparam, std::string ipath);
bool getOptions(int argc, const char **argv, std::string &ipath, bool &click_allowed, bool &display);
void usage(const char *name, const char *badparam, std::string ipath)
fprintf(stdout, "\n\
Tracking of Surf key-points.\n\
%s [-i <input image path>] [-c] [-d] [-h]\n",
fprintf(stdout, "\n\
OPTIONS: Default\n\
-i <input image path> %s\n\
Set image input path.\n\
From this path read \"line/image.%%04d.pgm\"\n\
images. \n\
Setting the VISP_INPUT_IMAGE_PATH environment\n\
variable produces the same behaviour than using\n\
this option.\n\
Disable the mouse click. Useful to automaze the \n\
execution of this program without humain intervention.\n\
-d \n\
Turn off the display.\n\
Print the help.\n",
if (badparam)
fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
bool getOptions(int argc, const char **argv, std::string &ipath, bool &click_allowed, bool &display)
const char *optarg_;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {
switch (c) {
case 'c':
click_allowed = false;
case 'd':
display = false;
case 'i':
ipath = optarg_;
case 'h':
usage(argv[0], NULL, ipath);
return false;
usage(argv[0], optarg_, ipath);
return false;
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL, ipath);
std::cerr << "ERROR: " << std::endl;
std::cerr << " Bad argument " << optarg_ << std::endl << std::endl;
return false;
return true;
int main(int argc, const char **argv)
try {
std::string env_ipath;
std::string opt_ipath;
std::string ipath;
std::string dirname;
std::string filename;
bool opt_click_allowed = true;
bool opt_display = true;
// Get the visp-images-data package path or VISP_INPUT_IMAGE_PATH
// environment variable value
// Set the default input path
if (!env_ipath.empty())
ipath = env_ipath;
// Read the command line options
if (getOptions(argc, argv, opt_ipath, opt_click_allowed, opt_display) == false) {
// Get the option values
if (!opt_ipath.empty())
ipath = opt_ipath;
// Compare ipath and env_ipath. If they differ, we take into account
// the input path comming from the command line option
if (!opt_ipath.empty() && !env_ipath.empty()) {
if (ipath != env_ipath) {
std::cout << std::endl << "WARNING: " << std::endl;
std::cout << " Since -i <visp image path=" << ipath << "> "
<< " is different from VISP_IMAGE_PATH=" << env_ipath << std::endl
<< " we skip the environment variable." << std::endl;
// Test if an input path is set
if (opt_ipath.empty() && env_ipath.empty()) {
usage(argv[0], NULL, ipath);
std::cerr << std::endl << "ERROR:" << std::endl;
std::cerr << " Use -i <visp image path> option or set VISP_INPUT_IMAGE_PATH " << std::endl
<< " environment variable to specify the location of the " << std::endl
<< " image path where test images are located." << std::endl
<< std::endl;
// Declare an image, this is a gray level image (unsigned char)
// it size is not defined yet, it will be defined when the image will
// read on the disk
// Set the path location of the image sequence
dirname = vpIoTools::createFilePath(ipath, "cube");
// Build the name of the image file
unsigned int iter = 0; // Image number
std::ostringstream s;
s.setf(std::ios::right, std::ios::adjustfield);
s << "image." << std::setw(4) << std::setfill('0') << iter << ".pgm";
filename = vpIoTools::createFilePath(dirname, s.str());
// Read the PGM image named "filename" on the disk, and put the
// bitmap into the image structure I. I is initialized to the
// correct size
// exception readPGM may throw various exception if, for example,
// the file does not exist, or if the memory cannot be allocated
try {
vpCTRACE << "Load: " << filename << std::endl;
vpImageIo::read(Iref, filename);
} catch (...) {
// an exception is throwned if an exception from readPGM has been
// catched here this will result in the end of the program Note that
// another error message has been printed from readPGM to give more
// information about the error
std::cerr << std::endl << "ERROR:" << std::endl;
std::cerr << " Cannot read " << filename << std::endl;
std::cerr << " Check your -i " << ipath << " option " << std::endl
<< " or VISP_INPUT_IMAGE_PATH environment variable." << std::endl;
// We open a window using either X11, GTK or GDI.
#if defined VISP_HAVE_X11
vpDisplayX display[2];
#elif defined VISP_HAVE_GTK
vpDisplayGTK display[2];
#elif defined VISP_HAVE_GDI
vpDisplayGDI display[2];
if (opt_display) {
try {
// Display size is automatically defined by the image (I) size
display[0].init(Iref, 100, 100, "Display reference image");
} catch (...) {
vpERROR_TRACE("Error while displaying the image");
vpImagePoint corners[2];
if (opt_display && opt_click_allowed) {
std::cout << "Click on the top left and the bottom right corners to "
"define the part of the image where the reference points "
"will be computed"
<< std::endl;
for (unsigned int i = 0; i < 2; i++) {
vpDisplay::getClick(Iref, corners[i]);
std::cout << corners[i] << std::endl;
} else {
corners[0].set_ij(156, 209);
corners[1].set_ij(272, 378);
if (opt_display) {
// Display the rectangle which defines the part of the image where the
// reference points are computed.
vpDisplay::displayRectangle(Iref, corners[0], corners[1], vpColor::green);
if (opt_click_allowed) {
std::cout << "Click on the image to continue" << std::endl;
vpKeyPointSurf surf;
// unsigned int nbrRef;
unsigned int height, width;
height = (unsigned int)(corners[1].get_i() - corners[0].get_i());
width = (unsigned int)(corners[1].get_j() - corners[0].get_j());
// Computes the reference points
/* nbrRef = */ surf.buildReference(Iref, corners[0], height, width);
vpImageIo::read(Icur, filename);
if (opt_display) {
try {
// Display size is automatically defined by the image (I) size
display[1].init(Icur, (int)(100 + Iref.getWidth()), 100, "Display current image");
} catch (...) {
vpERROR_TRACE("Error while displaying the image");
for (iter = 1; iter < 30; iter++) {
std::cout << "----------------------------------------------------------" << std::endl;
// set the new image name
s << "image." << std::setw(4) << std::setfill('0') << iter << ".pgm";
filename = vpIoTools::createFilePath(dirname, s.str());
// read the image
vpImageIo::read(Icur, filename);
if (opt_display) {
// Display the image
unsigned int nbrPair = surf.matchPoint(Icur);
std::cout << "Number of matched point : " << nbrPair << std::endl;
if (opt_display) {
// Display the matched features
surf.display(Iref, Icur, 7);
vpDisplay::displayRectangle(Iref, corners[0], corners[1], vpColor::red);
} catch (const vpException &e) {
std::cout << "Catch an exception: " << e << std::endl;
int main()
#if (!(defined(VISP_HAVE_X11) || defined(VISP_HAVE_GTK) || defined(VISP_HAVE_GDI)))
std::cout << "You do not have X11, or GTK, or GDI (Graphical Device Interface) functionalities to display images..."
<< std::endl;
std::cout << "Tip if you are on a unix-like system:" << std::endl;
std::cout << "- Install X11, configure again ViSP using cmake and build again this example" << std::endl;
std::cout << "Tip if you are on a windows-like system:" << std::endl;
std::cout << "- Install GDI, configure again ViSP using cmake and build again this example" << std::endl;
std::cout << "You do not have OpenCV with non free module functionalities" << std::endl;
std::cout << "Tip:" << std::endl;
std::cout << "- Install OpenCV with non free module, configure again ViSP using cmake and build again this example"
<< std::endl;
static const vpColor red
Definition: vpColor.h:217
static const vpColor green
Definition: vpColor.h:220
Display for windows using GDI (available on any windows 32 platform).
Definition: vpDisplayGDI.h:129
The vpDisplayGTK allows to display image using the GTK 3rd party library. Thus to enable this class G...
Definition: vpDisplayGTK.h:135
Use the X11 console to display images on unix-like OS. Thus to enable this class X11 should be instal...
Definition: vpDisplayX.h:135
static bool getClick(const vpImage< unsigned char > &I, bool blocking=true)
static void display(const vpImage< unsigned char > &I)
static void flush(const vpImage< unsigned char > &I)
static void displayRectangle(const vpImage< unsigned char > &I, const vpImagePoint &topLeft, unsigned int width, unsigned int height, const vpColor &color, bool fill=false, unsigned int thickness=1)
error that can be emited by ViSP classes.
Definition: vpException.h:72
static void read(vpImage< unsigned char > &I, const std::string &filename, int backend=IO_DEFAULT_BACKEND)
Definition: vpImageIo.cpp:148
Class that defines a 2D point in an image. This class is useful for image processing and stores only ...
Definition: vpImagePoint.h:89
double get_j() const
Definition: vpImagePoint.h:132
void set_ij(double ii, double jj)
Definition: vpImagePoint.h:320
double get_i() const
Definition: vpImagePoint.h:121
unsigned int getWidth() const
Definition: vpImage.h:246
static std::string getViSPImagesDataPath()
Definition: vpIoTools.cpp:1368
static std::string createFilePath(const std::string &parent, const std::string &child)
Definition: vpIoTools.cpp:1687
static bool parse(int *argcPtr, const char **argv, vpArgvInfo *argTable, int flags)
Definition: vpParseArgv.cpp:69
#define vpCTRACE
Definition: vpDebug.h:338
#define vpERROR_TRACE
Definition: vpDebug.h:393
Class that implements the SURF key points and technics thanks to the OpenCV library.