Visual Servoing Platform  version 3.5.0 under development (2022-02-15)
imageDiskRW.cpp

Reading and writting of PPM image using vpImageIo class.

Example of exception handling the exception : read an image that does not exist, write in a directory that does no exist

/****************************************************************************
*
* 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 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:
* Reading and writting images on the disk.
*
* Authors:
* Eric Marchand
*
*****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <visp3/core/vpDebug.h>
#include <visp3/core/vpImage.h>
#include <visp3/core/vpIoTools.h>
#include <visp3/io/vpImageIo.h>
#include <visp3/io/vpParseArgv.h>
// List of allowed command line options
#define GETOPTARGS "i:o:h"
void usage(const char *name, const char *badparam, std::string ipath, std::string opath, std::string user)
{
fprintf(stdout, "\n\
Read and write PGM images on the disk. Also test exceptions.\n\
\n\
SYNOPSIS\n\
%s [-i <input image path>] [-o <output image path>]\n\
[-h]\n \
", name);
fprintf(stdout, "\n\
OPTIONS: Default\n\
-i <input image path> %s\n\
Set image input path.\n\
From this path read \"Klimt/Klimt.pgm\"\n\
image.\n\
Setting the VISP_INPUT_IMAGE_PATH environment\n\
variable produces the same behaviour than using\n\
this option.\n\
\n\
-o <output image path> %s\n\
Set image output path.\n\
From this directory, creates the \"%s\"\n\
subdirectory depending on the username, where \n\
Klimt_grey.pgm output image is written.\n\
\n\
-h\n\
Print the help.\n\n", ipath.c_str(), opath.c_str(), user.c_str());
if (badparam) {
fprintf(stderr, "ERROR: \n");
fprintf(stderr, "\nBad parameter [%s]\n", badparam);
}
}
bool getOptions(int argc, const char **argv, std::string &ipath, std::string &opath, const std::string &user)
{
const char *optarg_;
int c;
while ((c = vpParseArgv::parse(argc, argv, GETOPTARGS, &optarg_)) > 1) {
switch (c) {
case 'i':
ipath = optarg_;
break;
case 'o':
opath = optarg_;
break;
case 'h':
usage(argv[0], NULL, ipath, opath, user);
return false;
break;
default:
usage(argv[0], optarg_, ipath, opath, user);
return false;
break;
}
}
if ((c == 1) || (c == -1)) {
// standalone param or error
usage(argv[0], NULL, ipath, opath, user);
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 opt_opath;
std::string ipath;
std::string opath;
std::string filename;
std::string username;
std::cout << "-------------------------------------------------------" << std::endl;
std::cout << " imageDiskRW.cpp" << std::endl << std::endl;
std::cout << " reading and writting of PPM image" << std::endl;
std::cout << " read an image that does not exist" << std::endl;
std::cout << " write in a directory that does no exist" << 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;
// Set the default output path
#if !defined(_WIN32) && (defined(__unix__) || defined(__unix) || (defined(__APPLE__) && defined(__MACH__))) // UNIX
opt_opath = "/tmp";
#elif defined(_WIN32)
opt_opath = "C:\\temp";
#endif
// Get the user login name
// Read the command line options
if (getOptions(argc, argv, opt_ipath, opt_opath, username) == false) {
return EXIT_SUCCESS;
}
// Get the option values
if (!opt_ipath.empty())
ipath = opt_ipath;
if (!opt_opath.empty())
opath = opt_opath;
// Append to the output path string, the login name of the user
std::string dirname = vpIoTools::createFilePath(opath, username);
// Test if the output path exist. If no try to create it
if (vpIoTools::checkDirectory(dirname) == false) {
try {
// Create the dirname
} catch (...) {
usage(argv[0], NULL, ipath, opath, username);
std::cerr << std::endl << "ERROR:" << std::endl;
std::cerr << " Cannot create " << dirname << std::endl;
std::cerr << " Check your -o " << opath << " option " << std::endl;
return EXIT_FAILURE;
}
}
// 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, opath, username);
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;
return EXIT_SUCCESS;
}
// First we wanted to have gray level image (8bits)
// vpImage is a template class you can declare vpImage of ...
// everything...
// Although I is a gray level image you can read and write
// color image. Obviously the color will be translated as a gray level
filename = vpIoTools::createFilePath(ipath, "Klimt/Klimt.ppm");
vpImageIo::read(I, filename);
filename = vpIoTools::createFilePath(dirname, "IoPPM.Klimt_char.ppm");
vpImageIo::write(I, filename);
// test io error
// if the image you want to read on the disk does not exist
// an exception is thrown
// Try to load a non existing image
try {
filename = vpIoTools::createFilePath(ipath, "image-that-does-not-exist.ppm");
vpImageIo::read(I, filename);
} catch (const vpException &e) {
std::cout << "Catch an expected exception: " << e << std::endl;
}
// same thing if you to write in a directory that does not exist
// or where you are not allowd to write.
try {
filename = vpIoTools::createFilePath(dirname, "directory-that-does-not-exist/Klimt.ppm");
vpImageIo::write(I, filename);
} catch (const vpException &e) {
std::cout << "Catch an expected exception: " << e << std::endl;
}
std::cout << "----------------------------------------------------" << std::endl;
// Let's consider that the image is now a color image (32 bits RGBa)
// read write unsigned char ppm image.
// Load a color image from the disk
filename = vpIoTools::createFilePath(ipath, "Klimt/Klimt.ppm");
vpImageIo::read(Irgba, filename);
// Write the content of the color image on the disk
filename = vpIoTools::createFilePath(dirname, "IoPGM.Klimt_rgba.ppm");
vpImageIo::write(Irgba, filename);
// test io error
try {
filename = vpIoTools::createFilePath(ipath, "image-that-does-not-exist.ppm");
vpImageIo::read(Irgba, filename);
} catch (const vpException &e) {
std::cout << "Catch an expected exception: " << e << std::endl;
}
// test io error
try {
filename = vpIoTools::createFilePath(dirname, "directory-that-does-not-exist/Klimt.ppm");
vpImageIo::write(Irgba, filename);
}
catch (const vpException &e) {
std::cout << "Catch an expected exception: " << e << std::endl;
}
return EXIT_SUCCESS;
} catch (const vpException &e) {
std::cout << "Catch an unexpected exception: " << e << std::endl;
return EXIT_FAILURE;
}
}