Visual Servoing Platform  version 3.2.0 under development (2018-10-24)
poseVirtualVS.cpp

Example of dots tracking in an image sequence and pose computation.

/****************************************************************************
*
* This file is part of the ViSP software.
* Copyright (C) 2005 - 2017 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 http://visp.inria.fr 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 visp@inria.fr
*
* This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Description:
* Pose computation on an object made of dots.
* reading of PGM image
* Display image using either the X11 or GTK or GDI display
* track 4 dots (vpDots) in the image
* compute the pose
*
* Authors:
* Eric Marchand
* Anthony Saunier
*
*****************************************************************************/
#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) || defined(VISP_HAVE_OPENCV))
#include <visp3/core/vpImage.h>
#include <visp3/core/vpImagePoint.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/gui/vpDisplayGDI.h>
#include <visp3/gui/vpDisplayGTK.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/gui/vpDisplayX.h>
#include <visp3/blob/vpDot.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/core/vpPixelMeterConversion.h>
#include <visp3/io/vpParseArgv.h>
#include <visp3/vision/vpPose.h>
// List of allowed command line options
#define GETOPTARGS "cdi:p:hf:n:s:"
void usage(const char *name, const char *badparam, std::string ipath, std::string ppath, unsigned first,
unsigned nimages, unsigned step);
bool getOptions(int argc, const char **argv, std::string &ipath, std::string &ppath, unsigned &first, unsigned &nimages,
unsigned &step, bool &click_allowed, bool &display);
void usage(const char *name, const char *badparam, std::string ipath, std::string ppath, unsigned first,
unsigned nimages, unsigned step)
{
fprintf(stdout, "\n\
Test dot tracking.\n\
\n\
SYNOPSIS\n\
%s [-i <input image path>] [-p <personal image path>]\n\
[-f <first image>] [-n <number of images>] [-s <step>][-c] [-d] [-h]\n", name);
fprintf(stdout, "\n\
OPTIONS: Default\n\
-i <input image path> %s\n\
Set image input path.\n\
From this path read images \n\
\"cube/image.%%04d.pgm\"\n\
Setting the VISP_INPUT_IMAGE_PATH environment\n\
variable produces the same behaviour than using\n\
this option.\n\
\n\
-p <personal image path> %s\n\
Specify a personal sequence containing images \n\
to process.\n\
By image sequence, we mean one file per image.\n\
The following image file formats PNM (PGM P5, PPM P6)\n\
are supported. The format is selected by analysing \n\
the filename extension.\n\
Example : \"/Temp/ViSP-images/cube/image.%%04d.pgm\"\n\
%%04d is for the image numbering.\n\
\n\
-f <first image> %u\n\
First image number of the sequence.\n\
\n\
-n <number of images> %u\n\
Number of images to load from the sequence.\n\
\n\
-s <step> %u\n\
Step between two images.\n\
\n\
-c\n\
Disable the mouse click. Useful to automaze the \n\
execution of this program without humain intervention.\n\
\n\
-d \n\
Turn off the display.\n\
\n\
-h\n\
Print the help.\n", ipath.c_str(), ppath.c_str(), first, nimages, step);
if (badparam)
fprintf(stdout, "\nERROR: Bad parameter [%s]\n", badparam);
}
bool getOptions(int argc, const char **argv, std::string &ipath, std::string &ppath, unsigned &first, unsigned &nimages,
unsigned &step, 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;
break;
case 'd':
display = false;
break;
case 'i':
ipath = optarg_;
break;
case 'p':
ppath = optarg_;
break;
case 'f':
first = (unsigned)atoi(optarg_);
break;
case 'n':
nimages = (unsigned)atoi(optarg_);
break;
case 's':
step = (unsigned)atoi(optarg_);
break;
case 'h':
usage(argv[0], NULL, ipath, ppath, first, nimages, step);
return false;
break;
default:
usage(argv[0], optarg_, ipath, ppath, first, nimages, step);
return false;
break;
}
}
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL, ipath, ppath, first, nimages, step);
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 opt_ppath;
std::string dirname;
std::string filename;
unsigned opt_first = 0;
unsigned opt_nimages = 80;
unsigned opt_step = 1;
bool opt_click_allowed = true;
bool opt_display = true;
int i;
std::cout << "-------------------------------------------------------" << std::endl;
std::cout << " poseVirtualVS.cpp" << std::endl << std::endl;
std::cout << " Example of dots tracking in an image sequence and pose "
"computation"
<< std::endl;
std::cout << "-------------------------------------------------------" << std::endl;
std::cout << std::endl;
// 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_ppath, opt_first, opt_nimages, opt_step, opt_click_allowed,
opt_display) == false) {
exit(-1);
}
// 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() && opt_ppath.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() && opt_ppath.empty()) {
usage(argv[0], NULL, ipath, opt_ppath, opt_first, opt_nimages, opt_step);
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
<< " Use -p <personal image path> option if you want to " << std::endl
<< " use personal images" << std::endl
<< std::endl;
exit(-1);
}
// 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
unsigned iter = opt_first;
std::ostringstream s;
char cfilename[FILENAME_MAX];
if (opt_ppath.empty()) {
// Warning :
// the image sequence is not provided with the ViSP package
// therefore the program will return you an error :
// !! vpImageIoPnm.cpp: readPGM(#210) :couldn't read file
// /ViSP-images/cube/image.0001.pgm
// !! poseExample.cpp: main(#95) :Error while reading the image
// terminate called after throwing an instance of 'vpImageException'
//
// The sequence is available on the visp www site
// https://visp.inria.fr/download/
// in the download section. It is named "ViSP-images-x.y.z.tar.gz"
// directory name
dirname = vpIoTools::createFilePath(ipath, "cube");
// Build the name of the image file
s.setf(std::ios::right, std::ios::adjustfield);
s << "image." << std::setw(4) << std::setfill('0') << iter << ".pgm";
filename = vpIoTools::createFilePath(dirname, s.str());
} else {
sprintf(cfilename, opt_ppath.c_str(), iter);
filename = cfilename;
}
// define the vpDot structure, here 4 dots will tracked
vpDot d[4];
for (i = 0; i < 4; i++) {
// by using setGraphics, we request to see the all the pixel of the dot
// in green on the screen.
// It uses the overlay image plane.
// The default of this setting is that it is time consumming
if (opt_display) {
d[i].setGraphics(true);
} else {
d[i].setGraphics(false);
}
}
// Read the PGM image named "s" 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 {
vpImageIo::read(I, 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
if (opt_ppath.empty()) {
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;
} else {
std::cerr << std::endl << "ERROR:" << std::endl;
std::cerr << " Cannot read " << filename << std::endl;
std::cerr << " or your -p " << opt_ppath << " option " << std::endl << std::endl;
}
exit(-1);
}
// We open a window using either the X11 or GTK or GDI window manager
// it will be located in 100,100 and titled "tracking using vpDot"
// its size is automatically defined by the image (I) size
#if defined VISP_HAVE_X11
vpDisplayX display;
#elif defined VISP_HAVE_GTK
vpDisplayGTK display;
#elif defined VISP_HAVE_GDI
vpDisplayGDI display;
#elif defined VISP_HAVE_OPENCV
vpDisplayOpenCV display;
#endif
if (opt_display) {
// Display size is automatically defined by the image (I) size
display.init(I, 100, 100, "tracking using vpDot");
// display the image
// The image class has a member that specify a pointer toward
// the display that has been initialized in the display declaration
// therefore is is no longuer necessary to make a reference to the
// display variable.
// Flush the display
}
vpImagePoint cog[4]; // Center of gravity of the dot
if (opt_display && opt_click_allowed) {
// dot coordinates (u,v) = (column,row)
std::cout << "Click the four white dots on the object corner clockwise" << std::endl;
for (i = 0; i < 4; i++) {
// tracking is initalized if no other parameters are given
// to the iniTracking(..) method a right mouse click on the
// dot is expected dot location can also be specified
// explicitely in the initTracking method :
// d.initTracking(I,ip) where ip is the image point from
// where the dot need to be searched.
d[i].initTracking(I);
// track the dot and returns its coordinates in the image
// results are given in float since many many are usually considered
//
// an expcetion is thrown by the track method if
// - dot is lost
// - the number of pixel is too small
// - too many pixels are detected (this is usual when a "big"
// specularity
// occurs. The threshold can be modified using the
// setMaxDotSize() method
d[i].track(I, cog[i]);
}
} else {
cog[0].set_u(194);
cog[0].set_v(88);
d[0].initTracking(I, cog[0]);
d[0].track(I, cog[0]);
cog[1].set_u(225);
cog[1].set_v(84);
d[1].initTracking(I, cog[1]);
d[1].track(I, cog[1]);
cog[2].set_u(242);
cog[2].set_v(114);
d[2].initTracking(I, cog[2]);
d[2].track(I, cog[2]);
cog[3].set_u(212);
cog[3].set_v(131);
d[3].initTracking(I, cog[3]);
d[3].track(I, cog[3]);
}
if (opt_display) {
// display a red cross (size 10) in the image at the dot center
// of gravity location
//
// WARNING
// in the vpDisplay class member's when pixel coordinates
// are considered the first element is the row index and the second
// is the column index:
// vpDisplay::displayCross(Image, row index, column index, size,
// color) therefore u and v are inverted wrt to the vpDot
// specification
// Alternatively, to avoid this problem another set of member have
// been defined in the vpDisplay class.
// If the method name is postfixe with _uv the specification is :
// vpDisplay::displayCross_uv(Image, column index, row index, size,
// color)
for (i = 0; i < 4; i++)
// flush the X11 buffer
}
// --------------------------------------------------------
// Now wil compute the pose
//
// The pose will be contained in an homogeneous matrix cMo
// We need a structure that content both the 3D coordinates of the point
// in the object frame and the 2D coordinates of the point expressed in
// meter the vpPoint class is ok for that
vpPoint P[4];
// The vpPose class mainly contents a list of vpPoint (that is (X,Y,Z, x,
// y) )
vpPose pose;
// the list of point is cleared (if that's not done before)
pose.clearPoint();
// we set the 3D points coordinates (in meter !) in the object/world frame
double L = 0.04;
P[0].setWorldCoordinates(-L, -L, 0); // (X,Y,Z)
P[1].setWorldCoordinates(L, -L, 0);
P[2].setWorldCoordinates(L, L, 0);
P[3].setWorldCoordinates(-L, L, 0);
// set the camera intrinsic parameters
// see more details about the model in vpCameraParameters
double px = 600;
double py = 600;
double u0 = 192;
double v0 = 144;
vpCameraParameters cam(px, py, u0, v0);
// pixel-> meter conversion
for (i = 0; i < 4; i++) {
// u[i]. v[i] are expressed in pixel
// conversion in meter is achieved using
// x = (u-u0)/px
// y = (v-v0)/py
// where px, py, u0, v0 are the intrinsic camera parameters
double x = 0, y = 0;
P[i].set_x(x);
P[i].set_y(y);
}
// The pose structure is build, we put in the point list the set of point
// here both 2D and 3D world coordinates are known
for (i = 0; i < 4; i++) {
pose.addPoint(P[i]); // and added to the pose computation point list
}
// compute the initial pose using Dementhon method followed by a non
// linear minimisation method
// Pose by Lagrange it provides an initialization of the pose
// the pose is now refined using the virtual visual servoing approach
// Warning: cMo needs to be initialized otherwise it may diverge
if (opt_display) {
// display the compute pose
pose.display(I, cMo, cam, 0.05, vpColor::red);
}
// Covariance Matrix Computation
// Uncomment if you want to compute the covariance matrix.
// pose.setCovarianceComputation(true); //Important if you want
// tracker.getCovarianceMatrix() to work.
unsigned niter = 0;
// this is the loop over the image sequence
while (iter < opt_nimages) {
// set the new image name
if (opt_ppath.empty()) {
s.str("");
s << "image." << std::setw(4) << std::setfill('0') << iter << ".pgm";
filename = vpIoTools::createFilePath(dirname, s.str());
} else {
sprintf(cfilename, opt_ppath.c_str(), iter);
filename = cfilename;
}
// read the image
vpImageIo::read(I, filename);
if (opt_display) {
// Display the image
// Flush the display
}
// kill the point list
pose.clearPoint();
// track the dot
for (i = 0; i < 4; i++) {
// track the point
d[i].track(I, cog[i]);
if (opt_display) {
// display point location
}
// pixel->meter conversion
{
double x = 0, y = 0;
P[i].set_x(x);
P[i].set_y(y);
}
// and added to the pose computation point list
pose.addPoint(P[i]);
}
// the pose structure has been updated
// the pose is now updated using the virtual visual servoing approach
// Dementhon or lagrange is no longuer necessary, pose at the
// previous iteration is sufficient
if (opt_display) {
// display the compute pose
pose.display(I, cMo, cam, 0.05, vpColor::red);
}
// Covariance Matrix Display
// Uncomment if you want to print the covariance matrix.
// Make sure pose.setCovarianceComputation(true) has been called
// (uncomment below). std::cout << pose.getCovarianceMatrix() <<
// std::endl << std::endl;
niter++;
iter += opt_step;
}
return EXIT_SUCCESS;
} catch (const vpException &e) {
std::cout << "Catch a ViSP exception: " << e << std::endl;
return EXIT_FAILURE;
}
}
#else
int main()
{
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;
return EXIT_SUCCESS;
}
#endif