CMake linking error with OpenCV libraries - opencv

I'm working on a project which uses OpenCV development libraries found on my package manager. I'm currently using two machines to work on this project, my laptop and my desktop. When I compile the code on my laptop, I have no issues. However, I'm getting a linking error on my desktop, which is strange because both machines have all corresponding libraries.
The error message complains about an undefined reference to a set of methods that should be getting linked, but cannot be found. Here's the output from cmake and make:
cmake:
malak#bigblackbox:~/Dropbox/libcardreader/release$ cmake .. && make
-- The C compiler identification is GNU 4.7.2
-- The CXX compiler identification is GNU 4.7.2
-- Check for working C compiler: /usr/bin/gcc
-- Check for working C compiler: /usr/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/malak/Dropbox/libcardreader/release
make:
Scanning dependencies of target test
[ 33%] Building CXX object CMakeFiles/test.dir/test.cpp.o
[ 66%] Building CXX object CMakeFiles/test.dir/libimganalyzer.cpp.o
[100%] Building CXX object CMakeFiles/test.dir/libcardreader.cpp.o
Linking CXX executable test
CMakeFiles/test.dir/libimganalyzer.cpp.o: In function `cv::MSER::~MSER()':
libimganalyzer.cpp:(.text._ZN2cv4MSERD1Ev[_ZN2cv4MSERD1Ev]+0xe): undefined reference to `vtable for cv::MSER'
libimganalyzer.cpp:(.text._ZN2cv4MSERD1Ev[_ZN2cv4MSERD1Ev]+0x26): undefined reference to `vtable for cv::MSER'
libimganalyzer.cpp:(.text._ZN2cv4MSERD1Ev[_ZN2cv4MSERD1Ev]+0x2e): undefined reference to `VTT for cv::MSER'
libimganalyzer.cpp:(.text._ZN2cv4MSERD1Ev[_ZN2cv4MSERD1Ev]+0x55): undefined reference to `cv::Algorithm::~Algorithm()'
libimganalyzer.cpp:(.text._ZN2cv4MSERD1Ev[_ZN2cv4MSERD1Ev]+0x8a): undefined reference to `cv::Algorithm::~Algorithm()'
collect2: error: ld returned 1 exit status
make[2]: *** [test] Error 1
make[1]: *** [CMakeFiles/test.dir/all] Error 2
make: *** [all] Error 2
libimganalyzer.cpp has an #include statement to reference libimganalyzer.h and here is what I reference in libimganalyzer.h:
#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/features2d/features2d.hpp>
If I use cat to look at the contents of features2d.hpp, which is where MSER is defined, it shows up:
malak#bigblackbox:~/Dropbox/libcardreader/release$ cat /usr/include/opencv2/features2d/features2d.hpp | grep MSER
typedef struct CvMSERParams
/////// the next few params for MSER of color image
} CvMSERParams;
CVAPI(CvMSERParams) cvMSERParams( int delta CV_DEFAULT(5), int min_area CV_DEFAULT(60),
CVAPI(void) cvExtractMSER( CvArr* _img, CvArr* _mask, CvSeq** contours, CvMemStorage* storage, CvMSERParams params );
/////// The class implements MSER algorithm introduced by J. Matas.
class CV_EXPORTS_W MSER : public CvMSERParams
CV_WRAP MSER();
CV_WRAP MSER( int _delta, int _min_area, int _max_area,
//! the operator that extracts the MSERs from the image or the specific part of it
MserFeatureDetector( CvMSERParams params=cvMSERParams() );
MSER mser;
malak#bigblackbox:~/Dropbox/libcardreader/release$
and here is the output of my CMakeLists.txt file:
set( CMAKE_AUTOMOC ON )
cmake_minimum_required(VERSION 2.8)
project( test )
find_package( OpenCV REQUIRED )
add_executable( test test.cpp libimganalyzer.cpp libimganalyzer.h libcardreader.cpp libcardreader.h )
target_link_libraries( test ${OpenCV_LIBS} )
I'd like to know what it is I lack on my desktop that lets me compile this project on my laptop without a hitch.
Update: I've tried multiple scenarios in terms of cmake and make on both my laptop and desktop and here's the results if it helps any:
cmake on desktop; make on desktop: cmake is successful, make throws error above.
cmake on desktop; make on laptop: cmake is successful, make is successful. Project runs.
cmake on laptop; make on desktop: cmake is successful, make is successful. Project runs.
cmake on laptop; make on laptop: cmake is successful, make is successful. Project runs.

Related

fatal error: opencv2/core/core.hpp: No such file or directory when compiling caffe

I kept getting this error:
PROTOC src/caffe/proto/caffe.proto
CXX .build_release/src/caffe/proto/caffe.pb.cc
CXX src/caffe/layer.cpp
CXX src/caffe/blob.cpp
CXX src/caffe/syncedmem.cpp
CXX src/caffe/solver.cpp
CXX src/caffe/data_transformer.cpp
src/caffe/data_transformer.cpp:1:10: fatal error: opencv2/core/core.hpp: No such file or directory
1 | #include <opencv2/core/core.hpp>
| ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:525: .build_release/src/caffe/data_transformer.o] Error 1
I don't understand where I go wrong. I'm using OpenCV 4.4.0 but it kept saying fatal error on opencv2. I also have installed all the dependencies that needed. does anyone have any idea about it? please help me.
If your opencv is correctly compiled and installed, it should be just a redundant directory. There is a directory opencv2 in the directory named opencv4, and then the specific classification file. That's what caffe compiling needs and why it kept saying fatal error on opencv2.
Solution: Put the entire copy of the opencv2 folder under the directory /usr/local/include/opencv4, and put it in the upper directory /usr/local/include, to compile Caffe normally (although there are other problems).
I encountered the same problem in the Ubuntu18 system with opencv4.2.0. It seems that opencv4 is too high to compile caffe. If you go on with it, there will be more errors because of it. I suggest you compile caffe with cuda8 and opencv3.X.

mapbox-gl-native not compiling with XCode 12

I downloaded the master for mapbox-gl-native, installed needed dependencies, followed instructions, then tried to build with "cmake --build build" but I get a lot of errors.
This is the first error:
[ 8%] Building CXX object CMakeFiles/mbgl-core.dir/src/mbgl/layermanager/circle_layer_factory.cpp.o
In file included from /Users/imac/Work/GitHub/mapbox-gl-native/src/mbgl/layermanager/circle_layer_factory.cpp:1:
In file included from /Users/imac/Work/GitHub/mapbox-gl-native/include/mbgl/layermanager/circle_layer_factory.hpp:3:
In file included from /Users/imac/Work/GitHub/mapbox-gl-native/include/mbgl/layermanager/layer_factory.hpp:3:
In file included from /Users/imac/Work/GitHub/mapbox-gl-native/include/mbgl/style/layer.hpp:3:
In file included from /Users/imac/Work/GitHub/mapbox-gl-native/include/mbgl/style/conversion.hpp:3:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string:504:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/string_view:175:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__string:57:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/algorithm:642:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/utility:199:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__tuple:283:5: error: static_assert failed due to
requirement '0UL < sizeof...(_Types)' "tuple_element index out of range"
static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range");
^ ~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__tuple:457:43: note: in instantiation of template class
'std::__1::tuple_element<0, std::__1::__tuple_types<> >' requested here
typedef _LIBCPP_NODEBUG_TYPE typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:1007:10: note: in instantiation of template class
'std::__1::tuple_element<0, std::__1::tuple<> >' requested here
typename tuple_element<_Ip, tuple<_Tp...> >::type&
^
/Users/imac/Work/GitHub/mapbox-gl-native/include/mbgl/util/indexed_tuple.hpp:38:16: note: while substituting deduced template arguments into function template 'get'
[with _Ip = 0, _Tp = <>]
return std::get<TypeIndex<I, Is...>::value, Ts...>(*this);
^
/Users/imac/Work/GitHub/mapbox-gl-native/src/mbgl/layout/circle_layout.hpp:20:59: note: in instantiation of function template specialization
'mbgl::IndexedTuple<mbgl::TypeList<mbgl::style::CircleSortKey>, mbgl::TypeList<mbgl::style::PropertyValue<float> > >::get<mbgl::style::CircleSortKey>'
requested here
const bool sortFeaturesByKey = !unevaluatedLayout.get<style::CircleSortKey>().isUndefined();
^
This is the result for: "gcc --version"
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 12.0.0 (clang-1200.0.32.2)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
This is the result for: "cmake . -B build"
-- The CXX compiler identification is AppleClang 12.0.0.12000032
-- The C compiler identification is AppleClang 12.0.0.12000032
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Configuring GL-Native with OpenGL renderer backend
-- Found OpenGL: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/OpenGL.framework
-- Found PkgConfig: /usr/local/bin/pkg-config (found version "0.29.2")
-- Checking for one of the modules 'glfw3'
-- Not building node bindings, dependencies not found. Run 'npm update'.
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/imac/Work/GitHub/mapbox-gl-native/build
NOTE: I have an older version of mapbox environment (July 2019) that was perfectly compiling with XCode (compiling inside XCode) but as soon as I installed XCode 12 I started to have the same error.

undefined reference to `cv::xfeatures2d::SURF::create(double, int, int, bool, bool)' during runtime

I am creating an app on the nvidia jetson nano (under ubuntu 18.04 LTS) using Qt-creator. To do so I create my own library (named recolib) which uses opencv (version 3.4.6) and then in my Qt app project I include my library.
The library compiles fine, but when I tried compiling the app it reaches 100% and then I get the following error: undefined reference to `cv::xfeatures2d::SURF::create(double, int, int, bool, bool)'.
Note that the class where this function is called is part of my library "recolib".
I have build opencv with cmake, I have enabled non-free modules and gave the right path to it and opencv built and installed fine.
Moreover, the app works well on mac and on an ubuntu virtual machine.
Here are samples of the Cmakelist.txt of the app:
cmake_minimum_required(VERSION 3.0)
# Add folder where are supportive functions
set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -std=c++11 -pthread -lm")
SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -std=c++11 -pthread -lm")
...
find_package(OpenCV REQUIRED)
if(OPENCV_XFEATURES2D_FOUND)
message("xfeatures2d found")
endif()
...
SET(RECOLIB_DIR "${PROJECT_SOURCE_DIR}/libs/recotracking-recolib")
include_directories("${RECOLIB_DIR}/include")
if(WIN32)
link_directories("${RECOLIB_DIR}/build/Debug")
else()
link_directories("${RECOLIB_DIR}/build/")
endif()
SET(RECOLIB_LIBRARY recolib)
include_directories(${OPENCV_INCLUDE_DIRS})
...
include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
FILE(GLOB_RECURSE RES_FILES "${CMAKE_CURRENT_SOURCE_DIR}/*.qrc")
FILE(GLOB_RECURSE SRC_FILES "${SRC_FOLDER}/*.cpp")
FILE(GLOB_RECURSE UI_FILES "${SRC_FOLDER}/*.ui")
FILE(GLOB_RECURSE HDR_FILES "${HDR_FOLDER}/*.h")
link_directories(${OpenCV_LIBRARY_DIRS})
message("opencv libs: ${OpenCV_LIBRARIES}")
add_executable(${execName} ${OS_BUNDLE}# Expands to WIN32 or MACOS_BUNDLE depending on OS
${RES_FILES} ${SRC_FILES} ${UI_FILES} ${HDR_FILES} ${META_FILES_TO_INCLUDE}
)
...
# Add the Qt5 Widgets for linking
if (APPLE)
target_link_libraries(${execName}
${OpenCV_LIBRARIES}
${AppKit}
${CoreAudio}
${AudioToolbox}
Qt5::Core
Qt5::Gui
Qt5::QuickControls2
Qt5::MultimediaWidgets
Qt5::Multimedia
Qt5::MultimediaPrivate
Qt5::Widgets
Qt5::Sql
${RECOLIB_LIBRARY})
else()
target_link_libraries(${execName}
${OpenCV_LIBRARIES}
Qt5::Core
Qt5::Gui
Qt5::QuickControls2
Qt5::MultimediaWidgets
Qt5::Multimedia
#Qt5::MultimediaPrivate
Qt5::Widgets
Qt5::Sql
${RECOLIB_LIBRARY})
endif()
And the output I get executing it under Qt-creator is the following:
Running "/usr/bin/cmake -E server --pipe=/tmp/cmake-Bg9h0e/socket --experimental" in /home/bookbeo-novatech/build-recotracking-app-Desktop-Release.
Starting to parse CMake project, using: "-DCMAKE_BUILD_TYPE:STRING=Release", "-DCMAKE_CXX_COMPILER:STRING=/usr/bin/g++", "-DCMAKE_C_COMPILER:STRING=/usr/bin/gcc", "-DCMAKE_PREFIX_PATH:STRING=/usr", "-DQT_QMAKE_EXECUTABLE:STRING=/usr/lib/qt5/bin/qmake".
-std=c++11 -pthread -lm
The C compiler identification is GNU 7.4.0
The CXX compiler identification is GNU 7.4.0
Check for working C compiler: /usr/bin/gcc
Check for working C compiler: /usr/bin/gcc -- works
Detecting C compiler ABI info
Detecting C compiler ABI info - done
Detecting C compile features
Detecting C compile features - done
Check for working CXX compiler: /usr/bin/g++
Check for working CXX compiler: /usr/bin/g++ -- works
Detecting CXX compiler ABI info
Detecting CXX compiler ABI info - done
Detecting CXX compile features
Detecting CXX compile features - done
Looking for pthread.h
Looking for pthread.h - found
Looking for pthread_create
Looking for pthread_create - not found
Looking for pthread_create in pthreads
Looking for pthread_create in pthreads - not found
Looking for pthread_create in pthread
Looking for pthread_create in pthread - found
Found Threads: TRUE
Found CUDA: /usr/local/cuda (found suitable exact version "10.0")
Found OpenCV: /usr/local (found version "3.4.6")
xfeatures2d found
opencv libs: opencv_calib3d;opencv_core;opencv_cudaarithm;opencv_cudabgsegm;opencv_cudacodec;opencv_cudafeatures2d;opencv_cudafilters;opencv_cudaimgproc;opencv_cudalegacy;opencv_cudaobjdetect;opencv_cudaoptflow;opencv_cudastereo;opencv_cudawarping;opencv_cudev;opencv_dnn;opencv_features2d;opencv_flann;opencv_highgui;opencv_imgcodecs;opencv_imgproc;opencv_ml;opencv_objdetect;opencv_photo;opencv_shape;opencv_stitching;opencv_superres;opencv_video;opencv_videoio;opencv_videostab;opencv_aruco;opencv_bgsegm;opencv_bioinspired;opencv_ccalib;opencv_cvv;opencv_datasets;opencv_dnn_objdetect;opencv_dpm;opencv_face;opencv_fuzzy;opencv_hfs;opencv_img_hash;opencv_line_descriptor;opencv_optflow;opencv_phase_unwrapping;opencv_plot;opencv_reg;opencv_rgbd;opencv_saliency;opencv_stereo;opencv_structured_light;opencv_surface_matching;opencv_text;opencv_tracking;opencv_xfeatures2d;opencv_ximgproc;opencv_xobjdetect;opencv_xphoto
Configuring done
Generating done
CMake Warning:
Manually-specified variables were not used by the project:
QT_QMAKE_EXECUTABLE
CMake Project was parsed successfully.
So as you can see, except for some issues with pthread (but it seems unrelated to the main problem), the cmake configuration appears to be good. Opencv is found and xfeatures2d too.
But when I build the app, at the end of the compilation I get:
[ 94%] Building CXX object CMakeFiles/recotracking-app.dir/recotracking-app_autogen/mocs_compilation.cpp.o
[ 97%] Building CXX object CMakeFiles/recotracking-app.dir/recotracking-app_autogen/EWIEGA46WW/qrc_resources.cpp.o
[100%] Linking CXX executable recotracking-app
/home/bookbeo/recotracking-app/libs/recotracking-recolib/build/librecolib.a(PCB.cpp.o): In function `reco::PCB::load(cv::Mat const&, cv::Mat const&, cv::Mat const&, std::vector<reco::RecoPoi, std::allocator<reco::RecoPoi> >)':
CMakeFiles/recotracking-app.dir/build.make:1045: recipe for target 'recotracking-app' failed
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/recotracking-app.dir/all' failed
Makefile:83: recipe for target 'all' failed
/home/bookbeo-novatech/recotracking-app/libs/recotracking-recolib/src/PCB.cpp:47: undefined reference to `cv::xfeatures2d::SURF::create(double, int, int, bool, bool)'
collect2: error: ld returned 1 exit status
make[2]: *** [recotracking-app] Error 1
make[1]: *** [CMakeFiles/recotracking-app.dir/all] Error 2
make: *** [all] Error 2
10:51:49: Le processus "/usr/bin/cmake" s'est terminé avec le code 2.
Erreur lors de la compilation/déploiement du projet recotracking-app (kit : Desktop)
When executing step "CMake Build"
10:51:49: Temps écoulé : 06:59.
I already tried re-building opencv, it didn't change anything, and the module xfeatures2d seems to be found so I don't know where this error is coming from.
If you have any idea, I would really appreciate it.
Thanks in advance.

QT Creator links different library than command line

I have a problem I am unable to understand.
I am trying to code a project using openCV 3.1. I want to code inside the QT Creator Environment, because I'm used to that. I do not necessarily need any QT specific features at the moment, I'm working with Ubuntu 14.04.
The problem is, that whenever I try to build inside the QT Creator, it does not build with the following error, but it works if I build from the command line.
10:57:36: Starting: "/usr/bin/cmake" --build . --target all
Linking CXX executable arucoTest
CMakeFiles/arucoTest.dir/PoseEstimator.cpp.o: In function `PoseEstimator::generateMarkers(std::string, int)':
PoseEstimator.cpp:(.text+0x56): undefined reference to `cv::aruco::getPredefinedDictionary(cv::aruco::PREDEFINED_DICTIONARY_NAME)'
PoseEstimator.cpp:(.text+0xb7): undefined reference to `cv::aruco::drawMarker(cv::Ptr<cv::aruco::Dictionary>&, int, int, cv::_OutputArray const&, int)'
PoseEstimator.cpp:(.text+0x1a9): undefined reference to `cv::imwrite(cv::String const&, cv::_InputArray const&, std::vector<int, std::allocator<int> > const&)'
CMakeFiles/arucoTest.dir/PoseEstimator.cpp.o: In function `cv::String::~String()':
PoseEstimator.cpp:(.text._ZN2cv6StringD2Ev[_ZN2cv6StringD5Ev]+0x14): undefined reference to `cv::String::deallocate()'
CMakeFiles/arucoTest.dir/PoseEstimator.cpp.o: In function `cv::String::String(std::string const&)':
PoseEstimator.cpp:(.text._ZN2cv6StringC2ERKSs[_ZN2cv6StringC5ERKSs]+0x69): undefined reference to `cv::String::allocate(unsigned long)'
collect2: error: ld returned 1 exit status
make[2]: *** [arucoTest] Error 1
make[1]: *** [CMakeFiles/arucoTest.dir/all] Error 2
make: *** [all] Error 2
10:57:36: The process "/usr/bin/cmake" exited with code 2.
So it is some kind of linker error. When I inspect my cmake file and output, I see this:
Running "/usr/bin/cmake /XYZ/arucoTest '-GCodeBlocks - Unix Makefiles'" in /XYZ/arucoTest/testbuild.
-- OpenCV library status:
-- version: 2.4.8
-- libraries: opencv_videostab;opencv_video;opencv_ts;opencv_superres;opencv_stitching;opencv_photo;opencv_ocl;opencv_objdetect;opencv_ml;opencv_legacy;opencv_imgproc;opencv_highgui;opencv_gpu;opencv_flann;opencv_features2d;opencv_core;opencv_contrib;opencv_calib3d
-- include path: /usr/include/opencv;/usr/include
-- Configuring done
-- Generating done
-- Build files have been written to: /XYZ/arucoTest/testbuild
As you can see, it only finds openCV 2.4.8, which I still need because of old ROS Indigo projects. However, if I execute the exact same cmake file and build from the commandline, it works perfectly:
username#pc:/XYZ/arucoTest/build$ cmake ..
-- The C compiler identification is GNU 4.8.4
-- The CXX compiler identification is GNU 4.8.4
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- OpenCV library status:
-- version: 3.1.0
-- libraries: opencv_xphoto;opencv_xobjdetect;opencv_ximgproc;opencv_xfeatures2d;opencv_tracking;opencv_text;opencv_surface_matching;opencv_structured_light;opencv_stereo;opencv_saliency;opencv_rgbd;opencv_reg;opencv_plot;opencv_optflow;opencv_line_descriptor;opencv_fuzzy;opencv_face;opencv_dpm;opencv_dnn;opencv_datasets;opencv_ccalib;opencv_bioinspired;opencv_bgsegm;opencv_aruco;opencv_viz;opencv_videostab;opencv_videoio;opencv_video;opencv_superres;opencv_stitching;opencv_shape;opencv_photo;opencv_objdetect;opencv_ml;opencv_imgproc;opencv_imgcodecs;opencv_highgui;opencv_flann;opencv_features2d;opencv_core;opencv_calib3d
-- include path: /usr/local/include/opencv;/usr/local/include
-- Configuring done
-- Generating done
-- Build files have been written to: /XYZ/arucoTest/build
veith#roethlinLT:/XYZ/arucoTest/build$ make
Scanning dependencies of target arucoTest
[100%] Building CXX object CMakeFiles/arucoTest.dir/PoseEstimator.cpp.o
Linking CXX executable arucoTest
[100%] Built target arucoTest
As you can see I'm building in 2 different folders, because I found that if I cmake in the same folder, it does not work, even if I remove everything in that folder and cmake again from the command line. Also notice, that it finds 2 different include paths depending on where I start the cmake from.
My makefile looks like this (not very crazy), I'm using this exact same file for both cases.
project(arucoTest)
cmake_minimum_required(VERSION 2.8)
find_package(OpenCV REQUIRED)
message(STATUS "OpenCV library status:")
message(STATUS " version: ${OpenCV_VERSION}")
message(STATUS " libraries: ${OpenCV_LIBS}")
message(STATUS " include path: ${OpenCV_INCLUDE_DIRS}")
set(HEADER_LIST PoseEstimator.h)
set(SRC_LIST PoseEstimator.cpp)
add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(${PROJECT_NAME} ${OpenCV_LIBS})
Using ccmake and the QT build in inspection window, I see that the OpenCV_DIR variable is set to 2 different things: On command line:
OpenCV_DIR /usr/local/share/OpenCV
In QT Creator:
OpenCV_DIR /ust/share/OpenCV
How do I set this to automatically select the right folder inside QT Creator as well? I really have no idea what could cause this!
Thanks!
Cache variable OpenCV_DIR is set by searching with command find_package (in config mode). While search mechanism is fully deterministic (it is described in the doc), it uses some envorinment variables which may differ under your shell and in QT Creator.
Just a guess, QT Creator may set CMAKE_PREFIX_PATH environment variable to contain /usr directory, so it finds an installation under /usr before one under /usr/local.
For choose specific OpenCV installation, just set OpenCV_DIR cache variable accordingly and rerun configuration process.

Opencv 'undefined reference to `cv::namedWindow....' (linking error)

I'm using the following CMake file to build an opencv project using the command cmake followed by make.
cmake_minimum_required(VERSION 2.8)
project(t)
#set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} /home/keiths/opencv/opencv-2.4.11_build/build)
SET(CMAKE_C_COMPILER mpicc)
SET(CMAKE_CXX_COMPILER mpicxx)
#set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
include_directories(${OpenCV_INCLUDE_DIRS})
find_package(OpenCV REQUIRED)
find_package(MPI REQUIRED)
add_executable(t t.cpp)
target_link_libraries(t ${OpenCV_LIBS} ${OpenCV_LIBRARIES} opencv_core opencv_highgui opencv_calib3d opencv_contrib opencv_core opencv_features2d opencv_flann opencv_gpu opencv_highgui opencv_imgproc opencv_legacy opencv_ml opencv_nonfree opencv_objdetect opencv_ocl opencv_photo opencv_stitching opencv_superres opencv_ts opencv_video opencv_videostab rt pthread m dl)
MESSAGE(${OpenCV_LIBS})
MESSAGE(${OpenCV_INCLUDE_DIRS})
cmake completes fine, but make gives me the following error:
CMakeFiles/t.dir/t.cpp.o: In function main': t.cpp:(.text+0x56):
undefined reference to
cv::namedWindow(std::__cxx11::basic_string, std::allocator > const&, int)' collect2:
error: ld returned 1 exit status make[2]: * [t] Error 1 make[1]: *
[CMakeFiles/t.dir/all] Error 2 make: *** [all] Error 2
I've tried running the following command
g++ t.cpp $(pkg-config --libs opencv --cflags)
but get the following error
/home/keiths/tmp/ccWFcaXH.o: In function main': t.cpp:(.text+0x56):
undefined reference to
cv::namedWindow(std::__cxx11::basic_string, std::allocator > const&, int)' collect2:
error: ld returned 1 exit status
I'm running the following simple code
#include "opencv2/opencv.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
//#include <mpi.h>
using namespace cv;
int main(int argc, char **argv) {
Mat image;
namedWindow( "Display window", WINDOW_AUTOSIZE );
return 0;
}
I've tried as many recommendations as I can without success. Platform is CentOS and I'm a limited user (non-root) with my locally installed (more recent) versions of g++/gcc. I get the correct list of libraries for the pkg-config command and have configured library paths as well as the PATH to my local opencv folder
Just to add a very important point, I tried compiling the same code while explicitly specifying the stock g++ compiler (/usr/bin/g++) and all went well. So it seems that the problem would be with my local g++ compiler at '/home/keiths/lbin'. I need this latest version however for the c++11 capability (the old is 4.4.7 and it would take ages for the Sysadmin to upgrade it)
I had built my OpenCV library using the old g++ compiler (in the system bin folder), prior to building the latest g++. Rebuilding the OpenCV library using the new g++ compiler did it for me. Out of curiosity, I tried building the OpenCV example using the old compiler and it returned many 'undefined reference' lines, but I'm happy to swap problems since I don't need it anyway!

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