I have installed OpenCV via homebrew, for my Mac OSX.
The problem I am having is that I am unable to use the imread openCV command at all. When I do, I get an error. Here is a breakdown of what I have done.
My simple code is:
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace std;
using namespace cv;
int main()
{
Mat imageMe = imread("frog.jpg", 0);
return 0;
}
To compile, I type this into the command prompt:
g++ opencvEntry.cpp -o opencvEntry `pkg-config --cflags --libs opencv` && ./opencvEntry
Upon doing that, the error message I get is:
Undefined symbols for architecture x86_64:
"cv::imread(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int)", referenced from:
_main in ccvT5f6R.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
So... I am not sure where/what is going on here. If I simply uncomment the imread line the file compiles just fine. However when uncommented, it does not recognize the command.
What is going on here?
I have the same issue, after searching, this is a solution which works for me, hope it can help you as well.
Compiling OpenCV code on a 64-bit mac
need LDFLAG of "-lopencv_imgproc".
Related
I there a way to compile a c++ file using script in atom that uses armadillo? I couldn't find anything related to it.
I already installed armadillo and tried compiling some basic code using script in atom:
#include <iostream>
#include <armadillo>
int main(int argc, const char **argv) {
arma::arma_rng::set_seed_random();
arma::Mat<double> A = arma::randu(4,4);
std::cout << "A:\n" << A << "\n";
return 0;
}
This is the error I got:
Undefined symbols for architecture x86_64:
"thread-local wrapper routine for arma::arma_rng_cxx11_instance", referenced from:
arma::arma_rng::set_seed(unsigned long long) in test1-83e853.o
arma::arma_rng::randu<double>::fill(double*, unsigned long long) in test1-83e853.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
If I read the source code for this atom-script thing correctly, it just hardcodes -Wall -include stdio.h as compilation options. You need to add -larmadillo to link it to the Armadillo library.
In short: you cannot use atom-script in combination with custom libraries, unless you edit the extension to hardcode the libraries in your compilation commandline.
I'm trying to use libuvc in one of my C/C++ projects. I succesfully compiled and installed both libusb and libuvc from source and when I attempt to compile the following code using gcc:
#include "libuvc/libuvc.h"
int main (int argc, const char **argv) {
uvc_init(NULL, NULL);
}
I get the following error:
Undefined symbols for architecture x86_64:
"_uvc_init", referenced from:
_main in main-de2855.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I'm on MacOS High Sierra 10.13.1 x64.
I used the command:
gcc main.c -luvc -o main
and it worked! Adding the -luvc flag solved my problem, but I don't understand why I need to use it. I've never needed flags before when working with other C/C++ dependencies.
First of all I want to say I realise this has been asked a dozen times, and I've read countless solutions without any luck so therefore I'm asking again.
I'm using OS X Mavericks 10.9.5, writing in Sublime 3 and compiling using terminal with g++
I'm trying to compile this simple file (test.cpp)
#include <iostream>
#include <SDL2/SDL.h>
int main () {
if(SDL_Init(SDL_INIT_VIDEO)) {
std::cout << "I made it this far" << std::endl;
}
return 0;
}
Compiler line :
g++ test.cpp
This returns the error :
Undefined symbols for architecture x86_64:
"_SDL_Init", referenced from:
_main in test-ebbae4.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
So, I've tried adding a lot of different flags, -m32 only changes the result to throw Undefined symbols for architecture i386: and ld: symbol(s) not found for architecture i386
I've tried different -arch variations, but I can't seem to get it to work. also played around with -l -I flags but I'm not sure I know what they do/how they could help..
Does anyone have a clue what to do next?
EDIT : Some additional information. I've tried using the .framework for SDL2, that didn't change anything, currently I'm using SDL2 installed through compilation of the source. Headers located in usr/local/SDL2
g++ test.cpp
You should specify the SDL library, too:
g++ test.cpp -lsdl2
You might need to include a path if its not well known to the compiler driver:
g++ test.cpp -L/path/to/the/library -lsdl2
Dear Friend please forgive me if the question i am about to ask sound stupid or very basic. I am trying to use the opencv for three days now and i am finding it very hard to compile the code in both Qt and XCODE, yesterday i was luck enough after gong through many tutorial was able to get one of the most basic codes working. The problem however is in some books i find example of codes written in this way:
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
int main( int argc, char** argv ) {
IplImage* img = cvLoadImage( "/Users/mughery/Desktop/1_s.jpg" );
cvNamedWindow( "Example1", CV_WINDOW_AUTOSIZE );
cvShowImage( "Example1", img );
cvWaitKey(0);
cvReleaseImage( &img );
cvDestroyWindow( "Example1" );
}
The above code works very fine, it has now problem what so ever, however when i test the code bellow i get a plenty of error. i believe they are both C++ code and they are supposedly doing the same thing.
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;
using namespace std;
int main()
{
//read an image
cv::Mat image = cv::imread("/Users/mughery/Desktop/1_s.jpg");
//create image window named "My Image"
cv::namedWindow("My Image");
cv::imshow("My image", image);
cv::waitKey(5000);
return 1;
}
When i run the second code it says library not found, the books are using the same library for both so what’s wrong can some one help please. The error i recive from the second code is
Ld /Users/mughery/Library/Developer/Xcode/DerivedData/Open-dvjwxosfuaihuabwnlxxuydfmyou/Build/Products/Debug/Open normal x86_64
cd /Users/mughery/Documents/ImageProgramtest/Open
export MACOSX_DEPLOYMENT_TARGET=10.9
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -L/Users/mughery/Library/Developer/Xcode/DerivedData/Open-dvjwxosfuaihuabwnlxxuydfmyou/Build/Products/Debug -L/usr/local/lib -F/Users/mughery/Library/Developer/Xcode/DerivedData/Open-dvjwxosfuaihuabwnlxxuydfmyou/Build/Products/Debug -filelist /Users/mughery/Library/Developer/Xcode/DerivedData/Open-dvjwxosfuaihuabwnlxxuydfmyou/Build/Intermediates/Open.build/Debug/Open.build/Objects-normal/x86_64/Open.LinkFileList -mmacosx-version-min=10.9 -stdlib=libstdc++ -lopencv_highgui.2.4.9 -lopencv_core.2.4.9 -Xlinker -dependency_info -Xlinker /Users/mughery/Library/Developer/Xcode/DerivedData/Open-dvjwxosfuaihuabwnlxxuydfmyou/Build/Intermediates/Open.build/Debug/Open.build/Objects-normal/x86_64/Open_dependency_info.dat -o /Users/mughery/Library/Developer/Xcode/DerivedData/Open-dvjwxosfuaihuabwnlxxuydfmyou/Build/Products/Debug/Open
Undefined symbols for architecture x86_64:
"cv::namedWindow(std::string const&, int)", referenced from:
_main in main.o
"cv::imread(std::string const&, int)", referenced from:
_main in main.o
"cv::imshow(std::string const&, cv::_InputArray const&)", referenced from:
_main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Both conventions are valid to use OpenCV functions in C++ code. The first code snippet uses C functions while the second one uses C++ functions. I reproduced your bug and it happens when you have changed the C++ Standard Library from the default of libc++ (LLVM C++ standard library) to libstdc++ (GNU C++ standard library) under the Build Settings of your Project.
If you use libc++ then both conventions work fine. For some reason, libstdc++ does not recognize the newer C++ functions.
The first code is uses c library while the below code uses c++ library...
1- Make sure you are linking the proper opencv libraries for both
2 - From the error code, it seems to me that the error is coming from mixing 32/64 bit libraries, try to match them.
I'm trying to compile the following program (using GDAL API in C++):
main.cpp:
#include "gdal_priv.h"
#include "cpl_conv.h"
int main(int argc, char *argv[])
{
GDALAllRegister();
GDALDataset* data = (GDALDataset*) GDALOpen( "heightmap.tiff", GA_ReadOnly );
}
the way I build it on a Mac :
clang main.cpp -I/Library/Frameworks/GDAL.framework/Versions/1.10/unix/include
and got this:
clang main.cpp -I/Library/Frameworks/GDAL.framework/Versions/1.10/unix/include/
Undefined symbols for architecture x86_64:
"_GDALOpenShared", referenced from:
_main in test_gdal-QIB6MK.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
What's wrong with this very basic case?
Try to build your project on a Mac using bash file:
#!/usr/bin/env bash
## Path to you installed GDAL
GDAL_PATH=/usr/local/Cellar/gdal2/2.2.0
INCLUDE_PATH=${GDAL_PATH}/include
LIBS_PATH=${GDAL_PATH}/lib
GDAL_LIB=-lgdal
g++ -I${INCLUDE_PATH} -L${LIBS_PATH} ${GDAL_LIB} main.cpp -o main