This is my CMakeLists.txt:
project(proj)
set(OpenCV_DIR "/usr/lib/opencv")
find_package(OpenCV REQUIRED COMPONENTS core imgproc highgui)
include_directories(${OpenCV_INCLUDE_DIRS})
add_executable(test test.cpp>
target_link_libraries(test ${OpenCV_LIBS})
and this is part of my code:
#include <opencv/cv.h>
#include <opencv/cv.hpp>
#include <opencv/highgui.h>
#include <opencv/highgui.hpp>
using namespace cv;
using namespace std;
int main(int argv, char **argc)
{
//other code
Mat img(height, width, CV_8UC3);
//other code
imwrite("/path", img);
namedWindow( "Display window", 1 );
imshow("Display window", img);
waitKey(0);
return 0;
}
and the error message I get is:
undefined reference to cv::imwrite(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, cv::Mat const&, std::vector<int, std::allocator<int> > const&)`
imshow works correctly, so I have no clue why imwrite is giving me an error.
EDIT:
g++ -o test_1 test_1.cpp `pkg-config opencv --cflags --libs`
gives the same error.
In your find_package() command, you are only selecting some specific modules from the OpenCV package, and the one you need (imgcodecs which provides imwrite()) is not in the list.
Try changing it to:
find_package(OpenCV)
Related
Here is the complete error:
Undefined symbols for architecture arm64:
"ug::UgWindow::UgWindow(int, int, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >)", referenced from:
_main in main.cpp.o
"ug::UgWindow::~UgWindow()", referenced from:
_main in main.cpp.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [untitled-game] Error 1
make[1]: *** [CMakeFiles/untitled-game.dir/all] Error 2
make: *** [all] Error 2
I am using cmake to build my files, i have created a UgWindow hpp file and cpp file to define its functionality here is the hpp file and cpp file.
HPP
#pragma once
#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>
#include <string>
namespace ug {
class UgWindow{
public:
UgWindow(int w, int h, std::string name);
~UgWindow();
bool shouldClose(){ return glfwWindowShouldClose(window); }
private:
void initWindow();
const int width;
const int height;
std::string windowName;
GLFWwindow *window;
};
}
here is the cpp file:
#include "ug_window.hpp"
namespace ug {
UgWindow::UgWindow(int w, int h, std::string name): width{w}, height{h}, windowName{name} {
initWindow();
}
UgWindow::~UgWindow() {
glfwDestroyWindow(window);
glfwTerminate();
}
void UgWindow::initWindow() {
glfwInit();
glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
window = glfwCreateWindow(width, height, windowName.c_str(), nullptr, nullptr);
}
}
I am trying to use vulkan with glfw and glm, im a noob with c++ and have absolutely no idea how to fix this or what the problem is.
Also this is my cmake file:
project(untitled-game)
cmake_minimum_required(VERSION 3.22.4)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O3 -std=c++17 " )
add_executable(${PROJECT_NAME} main.cpp)
find_package(Vulkan REQUIRED)
find_package(glfw3 3.3 REQUIRED)
if (VULKAN_FOUND)
message(STATUS "Found Vulkan, Including and Linking now")
include_directories(${Vulkan_INCLUDE_DIRS})
target_link_libraries (${PROJECT_NAME} ${Vulkan_LIBRARIES} glfw)
endif (VULKAN_FOUND)
add_executable(${PROJECT_NAME} main.cpp)
Here you say that the executable program is to be built from the main.cpp source file, and only the main.cpp source file.
You need to list all your source files:
add_executable(${PROJECT_NAME} main.cpp ug_window.cpp)
I am new at OpenCv. I am using Eclipse C/C++. When i try to run this sample code i faced with these errors. What should i do to solve this problem? Is there any problem at configurating ?
#using namespace std;
#using namespace cv;
int main( int argc, const char** argv )
{
Mat img = imread("MyPic.JPG", CV_LOAD_IMAGE_UNCHANGED);
if (img.empty()) //check whether the image is loaded or not
{
cout << "Error : Image cannot be loaded..!!" << endl;
//system("pause"); //wait for a key press
return -1;
}
namedWindow("MyWindow", CV_WINDOW_AUTOSIZE); //create a window with the name "MyWindow"
imshow("MyWindow", img); /
waitKey(0); //wait infinite time for a keypress
destroyWindow("MyWindow"); //destroy the window with the name, "MyWindow"
return 0;
}
16:11:28 **** Incremental Build of configuration Debug for project OpenCv ****
Info: Internal Builder is used for build
g++ "-IC:\\opencv\\build\\include" -O0 -g3 -Wall -c -fmessage-length=0 -o "src\\OpenCv.o" "..\\src\\OpenCv.cpp"
g++ "-LC:\\opencv\\build\\x86\\vc12\\lib" -o OpenCv.exe "src\\OpenCv.o" -lopencv_calib3d249 -lopencv_contrib249 -lopencv_core249 -lopencv_features2d249 -lopencv_flann249 -lopencv_gpu249 -lopencv_highgui249 -lopencv_imgproc249 -lopencv_legacy249 -lopencv_ml249 -lopencv_nonfree249 -lopencv_objdetect249 -lopencv_ocl249 -lopencv_photo249 -lopencv_stitching249 -lopencv_superres249 -lopencv_ts249 -lopencv_video249 -lopencv_videostab249
src\OpenCv.o: In function `main':
C:\Users\ayberk101\workspace\OpenCv\Debug/../src/OpenCv.cpp:10: undefined reference to `cv::imread(std::string const&, int)'
C:\Users\ayberk101\workspace\OpenCv\Debug/../src/OpenCv.cpp:19: undefined reference to `cv::namedWindow(std::string const&, int)'
C:\Users\ayberk101\workspace\OpenCv\Debug/../src/OpenCv.cpp:20: undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
C:\Users\ayberk101\workspace\OpenCv\Debug/../src/OpenCv.cpp:20: undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
C:\Users\ayberk101\workspace\OpenCv\Debug/../src/OpenCv.cpp:22: undefined reference to `cv::waitKey(int)'
C:\Users\ayberk101\workspace\OpenCv\Debug/../src/OpenCv.cpp:24: undefined reference to `cv::destroyWindow(std::string const&)'
src\OpenCv.o: In function `ZN2cv3MatD1Ev':
C:/opencv/build/include/opencv2/core/mat.hpp:278: undefined reference to `cv::fastFree(void*)'
src\OpenCv.o: In function `ZN2cv3Mat7releaseEv':
C:/opencv/build/include/opencv2/core/mat.hpp:367: undefined reference to `cv::Mat::deallocate()'
collect2.exe: error: ld returned 1 exit status
problem1: you will have to include opencv / c++ header files to make it work:
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#using namespace cv;
#include <iostream>
#using namespace std;
int main() {
...
then, problem2: you cannot use the vc12 libs with mingw. (it's a different compiler)
there are no more prebuild mingw libs for opencv, so, before doing anything else, you will have to build the opencv libs locally using cmake.
again, do you really need to use mingw / eclipse ? (vs express is still free)
I get an error when trying to compile a single .cpp file
Main.cpp:
#include "opencv2/core/core_c.h"
#include "opencv2/core/core.hpp"
#include "opencv2/flann/miniflann.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/video.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/ml/ml.hpp"
#include "opencv2/highgui/highgui_c.h"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/contrib/contrib.hpp"
#include <opencv2/gpu/gpu.hpp>
#include <iostream>
int main(int argc, char* argv[])
{
cv::VideoCapture capture = cv::VideoCapture(argv[1]);
cv::gpu::GpuMat gpu_frame,gpu_frame_binary;
cv::Mat frame;
int threshold_value = 80;
int threshold_type = 0;
while (1)
{
capture >> frame;
gpu_frame.upload(frame);
if (!frame.data)
break;
cv::gpu::threshold(gpu_frame, gpu_frame_binary, threshold_value, 255, threshold_type);
}
return 0;
}
OpenCV built with these options:
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_V4L=ON -D WITH_GSTREAMER=ON -D WITH_OPENEXR=ON -D WITH_UNICAP=ON -D BUILD_PYTHON_SUPPORT=ON -D INSTALL_C_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D ENABLE_SSE2=ON -D WITH_CUDA=ON ..
Command used to compile:
g++ -ggdb `pkg-config --cflags opencv` -o main main.cpp `pkg-config --libs opencv` -lopencv_gpu
And the error I get:
/usr/local/lib/libopencv_gpu.so: undefined reference to `cv::gpu::convertTo(cv::gpu::GpuMat const&, cv::gpu::GpuMat&, double, double, CUstream_st*)'
/usr/local/lib/libopencv_gpu.so: undefined reference to `cv::gpu::setTo(cv::gpu::GpuMat&, cv::Scalar_<double>, cv::gpu::GpuMat const&, CUstream_st*)'
/usr/local/lib/libopencv_gpu.so: undefined reference to `cv::gpu::setTo(cv::gpu::GpuMat&, cv::Scalar_<double>, CUstream_st*)'
collect2: error: ld returned 1 exit status
When I try to compile without the -lopencv_gpu option I get errors like:
main.cpp:61: undefined reference to `cv::gpu::threshold(cv::gpu::GpuMat const&, cv::gpu::GpuMat&, double, double, int, cv::gpu::Stream&)'
Any ideas what might be wrong?
P.S It may be important to note that I first built opencv without cuda, then decided that I wanted to try cuda and built it with cuda option on, and did sudo make install. I thought it would overwrite what was previously installed, but maybe something went wrong there?
Running on Fedora 20, with Nvidia card.
I encountered the same problem.
To solve it I just deleted libopencv_gpu.so.2.4 and libopencv_gpu.so.2.4.10 in /usr/local/lib/.
The code is simple and is essentially straight from this tutorial. I am running Arch Linux and have the OpenCV library stored at /usr/include/. I have also checked to ensure that /usr/include is in my PATH.
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <iostream>
using namespace cv;
int main(int argc, char** argv){
Mat image;
Mat grayImage;
if(!argv[1]){
std::cerr << "No image data!" << std::endl;
return -1;
}
image = imread(argv[1], 1);
cvtColor(image, grayImage, CV_BGR2GRAY);
imwrite("Gray_Image.jpg", grayImage);
namedWindow(argv[1], CV_WINDOW_AUTOSIZE);
namedWindow("Gray Image", CV_WINDOW_AUTOSIZE);
imshow(argv[1], image);
imshow("Gray Image", grayImage);
waitKey(0);
return 0;
}
The compiler process successfully finds and include these header files, but I still get undefined reference errors at compile-time. If you look into the header files I included they further include other files in /usr/include/opencv2. I have checked and such header files do exist.
Any ideas?
/tmp/ccudBcqD.o: In function `main':
test.cpp:(.text+0xc0): undefined reference to `cv::imread(std::string const&, int)'
test.cpp:(.text+0x11f): undefined reference to `cv::_OutputArray::_OutputArray(cv::Mat&)'
test.cpp:(.text+0x138): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x158): undefined reference to `cv::cvtColor(cv::_InputArray const&, cv::_OutputArray const&, int, int)'
test.cpp:(.text+0x180): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x1ca): undefined reference to `cv::imwrite(std::string const&, cv::_InputArray const&, std::vector<int, std::allocator<int> > const&)'
test.cpp:(.text+0x241): undefined reference to `cv::namedWindow(std::string const&, int)'
test.cpp:(.text+0x291): undefined reference to `cv::namedWindow(std::string const&, int)'
test.cpp:(.text+0x2bf): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x2ff): undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
test.cpp:(.text+0x32d): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x361): undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
test.cpp:(.text+0x383): undefined reference to `cv::waitKey(int)'
/tmp/ccudBcqD.o: In function `cv::Mat::~Mat()':
test.cpp:(.text._ZN2cv3MatD2Ev[_ZN2cv3MatD5Ev]+0x39): undefined reference to `cv::fastFree(void*)'
/tmp/ccudBcqD.o: In function `cv::Mat::operator=(cv::Mat const&)':
test.cpp:(.text._ZN2cv3MataSERKS0_[_ZN2cv3MataSERKS0_]+0x111): undefined reference to `cv::Mat::copySize(cv::Mat const&)'
/tmp/ccudBcqD.o: In function `cv::Mat::release()':
test.cpp:(.text._ZN2cv3Mat7releaseEv[_ZN2cv3Mat7releaseEv]+0x47): undefined reference to `cv::Mat::deallocate()'
collect2: error: ld returned 1 exit status
[Finished in 1.1s with exit code 1]
[shell_cmd: g++ "/home/branden/Desktop/OpenCV/test.cpp" -o "/home/branden/Desktop/OpenCV/test"]
[dir: /home/branden/Desktop/OpenCV]
[path: /usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/vendor_perl:/usr/bin/core_perl]
This is a linker issue. Try:
g++ -o test_1 test_1.cpp `pkg-config opencv --cflags --libs`
This should work to compile the source. However, if you recently compiled OpenCV from source, you will meet linking issue in run-time, the library will not be found.
In most cases, after compiling libraries from source, you need to do finally:
sudo ldconfig
I have tried all solutions. The -lopencv_core -lopencv_imgproc -lopencv_highgui in comments solved my problem. And now my command line looks like this in geany:
g++ -lopencv_core -lopencv_imgproc -lopencv_highgui -o "%e" "%f"
When I build:
g++ -lopencv_core -lopencv_imgproc -lopencv_highgui -o "opencv" "opencv.cpp" (in directory: /home/fedora/Desktop/Implementations)
The headers are:
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
follow this tutorial. i ran the install-opencv.sh file in bash. its in the tutorial
read the example from openCV
CMakeLists.txt
cmake_minimum_required(VERSION 3.7)
project(openCVTest)
# cmake needs this line
cmake_minimum_required(VERSION 2.8)
# Define project name
project(opencv_example_project)
# Find OpenCV, you may need to set OpenCV_DIR variable
# to the absolute path to the directory containing OpenCVConfig.cmake file
# via the command line or GUI
find_package(OpenCV REQUIRED)
# If the package has been found, several variables will
# be set, you can find the full list with descriptions
# in the OpenCVConfig.cmake file.
# Print some message showing some of them
message(STATUS "OpenCV library status:")
message(STATUS " version: ${OpenCV_VERSION}")
message(STATUS " libraries: ${OpenCV_LIBS}")
message(STATUS " include path: ${OpenCV_INCLUDE_DIRS}")
if(CMAKE_VERSION VERSION_LESS "2.8.11")
# Add OpenCV headers location to your include paths
include_directories(${OpenCV_INCLUDE_DIRS})
endif()
# Declare the executable target built from your sources
add_executable(main main.cpp)
# Link your application with OpenCV libraries
target_link_libraries(main ${OpenCV_LIBS})
main.cpp
/**
* #file LinearBlend.cpp
* #brief Simple linear blender ( dst = alpha*src1 + beta*src2 )
* #author OpenCV team
*/
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include <stdio.h>
using namespace cv;
/** Global Variables */
const int alpha_slider_max = 100;
int alpha_slider;
double alpha;
double beta;
/** Matrices to store images */
Mat src1;
Mat src2;
Mat dst;
//![on_trackbar]
/**
* #function on_trackbar
* #brief Callback for trackbar
*/
static void on_trackbar( int, void* )
{
alpha = (double) alpha_slider/alpha_slider_max ;
beta = ( 1.0 - alpha );
addWeighted( src1, alpha, src2, beta, 0.0, dst);
imshow( "Linear Blend", dst );
}
//![on_trackbar]
/**
* #function main
* #brief Main function
*/
int main( void )
{
//![load]
/// Read images ( both have to be of the same size and type )
src1 = imread("../data/LinuxLogo.jpg");
src2 = imread("../data/WindowsLogo.jpg");
//![load]
if( src1.empty() ) { printf("Error loading src1 \n"); return -1; }
if( src2.empty() ) { printf("Error loading src2 \n"); return -1; }
/// Initialize values
alpha_slider = 0;
//![window]
namedWindow("Linear Blend", WINDOW_AUTOSIZE); // Create Window
//![window]
//![create_trackbar]
char TrackbarName[50];
sprintf( TrackbarName, "Alpha x %d", alpha_slider_max );
createTrackbar( TrackbarName, "Linear Blend", &alpha_slider, alpha_slider_max, on_trackbar );
//![create_trackbar]
/// Show some stuff
on_trackbar( alpha_slider, 0 );
/// Wait until user press some key
waitKey(0);
return 0;
}
Tested in linux mint 17
if anyone still having this problem. One solution is to rebuild the source OpenCV library using MinGW and not use the binaries given by OpenCV. I did it and it worked like a charm.
I had the same error after compiling the opencv4 in linux.
I had to link the libraries after my .cpp files not before.
g++ $(pkg-config opencv4 --cflags) -std=c++17 foo.cpp $(pkg-config opencv4 --libs) -o foo.o
Note: I also passed -D OPENCV_GENERATE_PKGCONFIG=ON to the cmake command to generate the pkgconfig/opencv4.pc file - the pkg-config command needs it.
Read here for more info about why the order matters: Why does the order in which libraries are linked sometimes cause errors in GCC?
If you do the following, you will be able to use opencv build from OpenCV_INSTALL_PATH.
cmake_minimum_required(VERSION 2.8)
SET(OpenCV_INSTALL_PATH /home/user/opencv/opencv-2.4.13/release/)
SET(OpenCV_INCLUDE_DIRS "${OpenCV_INSTALL_PATH}/include/opencv;${OpenCV_INSTALL_PATH}/include")
SET(OpenCV_LIB_DIR "${OpenCV_INSTALL_PATH}/lib")
LINK_DIRECTORIES(${OpenCV_LIB_DIR})
set(OpenCV_LIBS opencv_core opencv_imgproc opencv_calib3d opencv_video opencv_features2d opencv_ml opencv_highgui opencv_objdetect opencv_contrib opencv_legacy opencv_gpu)
# find_package( OpenCV )
project(edge.cpp)
add_executable(edge edge.cpp)
For me, this type of error:
mingw-w64-x86_64/lib/gcc/x86_64-w64-mingw32/8.2.0/../../../../x86_64-w64-mingw32/bin/ld: mingw-w64-x86_64/x86_64-w64-mingw32/lib/libTransform360.a(VideoFrameTransform.cpp.obj):VideoFrameTransform.cpp:(.text+0xc7c):
undefined reference to `cv::Mat::Mat(cv::Mat const&, cv::Rect_<int> const&)'
meant load order, I had to do -lTransform360 -lopencv_dnn345 -lopencv... just like that, that order.
And putting them right next to each other helped too, don't put -lTransform360 all the way at the beginning...or you'll get, for some freaky reason:
undefined reference to `VideoFrameTransform_new'
undefined reference to `VideoFrameTransform_generateMapForPlane'
...
I just changed the position of paramters:
g++ -o test2.out test2.cpp pkg-config opencv4 --cflags --libs
Before I changed the position I used g++ pkg-config opencv4 --cflags --libs test2.cpp -o test2.out.
You can try to run pkg-config opencv --cflags --libs in terminal or run pkg-config opencv4 --cflags --libs to see if you can obtain any information.
I'm running the basic OpenCV example with OpenCV3.0.0 dev:
project(ImageDenoise)
cmake_minimum_required(VERSION 2.8)
aux_source_directory(. SRC_LIST)
find_package(OpenCV REQUIRED)
include_directories( ${OpenCV_INCLUDE_DIRS} )
add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(${PROJECT_NAME} ${OpenCV_LIBS})
MESSAGE(${OpenCV_LIBS})
MESSAGE(${OpenCV_INCLUDE_DIRS})
Source code:
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;
using namespace std;
int main(int argc, char* argv[] )
{
if ( argc != 2 )
{
printf("usage: DisplayImage.out <Image_Path>\n");
return -1;
}
Mat image;
image = imread( argv[1], IMREAD_COLOR );
if ( !image.data )
{
printf("No image data \n");
return -1;
}
namedWindow("Display Image", WINDOW_AUTOSIZE );
imshow("Display Image", image);
waitKey(0);
return 0;
}
When I import this project into QtCreator, I got the following linking errors when building project:
[100%] Building CXX object CMakeFiles/ImageDenoise.dir/main.cpp.o
Linking CXX executable ImageDenoise
CMakeFiles/ImageDenoise.dir/main.cpp.o: In function `main':
main.cpp:(.text+0x7c): undefined reference to `cv::imread(cv::String const&, int)'
main.cpp:(.text+0xf5): undefined reference to `cv::namedWindow(cv::String const&, int)'
main.cpp:(.text+0x144): undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
However when I run cmake from command line and using make, then it works perfectly. What is the reason behind this?
dzung#Cronus:~/kSVD/build$ make
Scanning dependencies of target ImageDenoise
[100%] Building CXX object CMakeFiles/ImageDenoise.dir/main.cpp.o
Linking CXX executable ImageDenoise
[100%] Built target ImageDenoise
dzung#Cronus:~/kSVD/build$ ls
CMakeCache.txt CMakeFiles cmake_install.cmake ImageDenoise Makefile
dzung#Cronus:~/kSVD/build$ ./ImageDenoise
usage: DisplayImage.out <Image_Path>
I had exactly the same issue. I think this is some sort of a Qt-creator bug.
I solved this by:
Remove everything except *.cpp and CMakeLists.txt in the project
folder.
Before creating anything with Qt-creator do: cmake . && make
Now open existing project in Qt-creator.
Now you can run cmake/compile/run etc just fine.