I installed Ubuntu 14.04 and Opencv using the steps mentioned here https://solarianprogrammer.com/2014/04/21/opencv-beaglebone-black-ubuntu/
I am trying to compile the following code (saved in text file named as test2.cpp. test2.cpp and lena.jpg were copied to beaglebone home folder) :
// Test to convert a color image to gray
// Build on Linux with:
// g++ test2.cpp -o test2 -lopencv_core -lopencv_imgproc -lopencv_highgui
#include <opencv2/opencv.hpp>
#include <iostream>
int main() {
// Load the image file and check for success
cv::Mat input = cv::imread("lena.jpg", 1);
if(!input.data) {
std::cout << "Unable to open the image file" << std::endl;
return -1;
}
// Convert the input file to gray
cv::Mat gray_image;
cvtColor(input, gray_image, cv::COLOR_BGR2GRAY);
// Save the result
cv::imwrite("lena_gray.jpg", gray_image);
return 0;
}
using g++ test2.cpp -o test2 -lopencv_core -lopencv_imgproc -lopencv_highgui
I also tried telling the compiler where the libraries are using -L /usr/local/lib . (the libopencv files were found there). But got the following error each time:
ubuntu#arm:~$ g++ test2.cpp -o test2 -lopencv_core -lopencv_imgproc -lopencv_highgui -L usr/local/lib
/tmp/cckXjOPd.o: In function `main':
test2.cpp:(.text+0x26): undefined reference to `cv::imread(cv::String const&, int)'
test2.cpp:(.text+0xf0): undefined reference to `cv::imwrite(cv::String const&, cv::_InputArray const&, std::vector<int, std::allocator<int=""> > const&)'
collect2: error: ld returned 1 exit status
Can someone help me out here? Any help would be appreciated.
I find it always convenient and safe to compile using:
g++ test2.cpp -o test2 `pkg-config --libs --cflags opencv`
Install pkg-config if not already present.
Related
I am trying to compile a program for the raspberry pi.
But when I run the build in Geany I got this error:
g++ $(pkg-config opencv4 --cflags --libs) -o g++ $(pkg-config raspicam --cflags --libs) -o camera_2 camera_2.cpp (in directory: /home/pi/Desktop)
/usr/bin/ld: /tmp/ccTDUfOT.o: undefined reference to symbol '_ZN2cv6imshowERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKNS_11_InputArrayE'
/usr/bin/ld: //usr/local/lib/libopencv_highgui.so.405: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Compilation failed.
The camera.cpp file looks like this:
#include <opencv2/opencv.hpp>
#include <raspicam_cv.h>
#include <iostream>
using namespace std;
using namespace cv;
using namespace raspicam;
Mat frame;
void Setup ( int argc,char **argv, RaspiCam_Cv &Camera )
{
Camera.set ( CAP_PROP_FRAME_WIDTH, ( "-w",argc,argv,400 ) );
Camera.set ( CAP_PROP_FRAME_HEIGHT, ( "-h",argc,argv,240 ) );
Camera.set ( CAP_PROP_BRIGHTNESS, ( "-br",argc,argv,50 ) );
Camera.set ( CAP_PROP_CONTRAST ,( "-co",argc,argv,50 ) );
Camera.set ( CAP_PROP_SATURATION, ( "-sa",argc,argv,50 ) );
Camera.set ( CAP_PROP_GAIN, ( "-g",argc,argv ,50 ) );
Camera.set ( CAP_PROP_FPS, ( "-fps",argc,argv,100));
}
int main(int argc,char **argv)
{
RaspiCam_Cv Camera;
Setup(argc, argv, Camera);
cout<<"Connecting to camera"<<endl;
if (!Camera.open())
{
cout<<"Failed to Connect"<<endl;
return -1;
}
cout<<"Camera Id = "<<Camera.getId()<<endl;
Camera.grab();
Camera.retrieve(frame);
imshow("frame", frame);
waitKey();
return 0;
}
So far I have figured that when I remove
Mat frame;
the error does not appear.
The pkg-config file looks like this:
prefix=/usr/local
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir_old=${prefix}/include/opencv4/opencv2
includedir_new=${prefix}/include/opencv4
Name: OpenCV
Description: Open Source Computer Vision Library
Version: 4.5.5
L: -Libs${exec_prefix}/lib -lopencv_calib3d -lopencv_core -lopencv_dnn -lopencv_features2d -lopencv_flann -lopencv_gapi -lopencv_highgui -lopencv_imgcodecs -lopencv_imgproc -lopencv_ml -lopencv_objdetect -lopencv_photo -lopencv_stitching -lopencv_video -lopencv_videoio
Libs.private: -ldl -lm -lpthread -lrt
Cflags: -I${includedir_old} -I${includedir_new}
The command in Geany looks like this:
g++ $(pkg-config opencv4 --cflags --libs) -o g++ $(pkg-config raspicam --cflags --libs) -o %e %f
Do you have any idea what is wrong and what I do have to change?
Thank you
The argument -o g++ is very weird because it will make an output file named g++, which is confusing because that's also the name of your compiler. You probably want to remove that since you already have a -o argument.
Secondly, the order of the different objects/libraries that are getting linked together often matters when you are linking a program. Try putting the calls to pkg-config at the end of the command.
I have solved the error.
I have added two libraries to the command:
g++ $(pkg-config opencv4 --cflags --libs) $(pkg-config raspicam --cflags --libs) -o %e %f -lopencv_highgui -lopencv_core
I wonder why the libraries do not work in the config file.
I have installed OpenCV 3.3.0 to Ubuntu 16.04. Just want to compile this code.
#include <iostream>
using namespace std;
#include "opencv2/opencv.hpp"
#include "opencv2/gpu/gpu.hpp"
#include <opencv2/opencv.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <cmath>
using namespace cv;
int main(int argc, char* argv[])
{
try
{
int kernel_size = 3;
cv::Mat src_host = cv::imread("crack2.jpg");
cv::Mat gray_img, avg, kernel;
cv::gpu::GpuMat dst, src;
src.upload(src_host);
cv::gpu::threshold(src, dst, 128.0, 255.0, CV_THRESH_BINARY);
cv::Mat result_host;
dst.download(result_host);
std::cout<< "Done!!!" <<std::endl;
}catch(const cv::Exception& ex)
{
std::cout<<"Error: " << ex.what() << std::endl;
}
return 0;
}
g++ -o main gpu_thresh.cpp 'pkg-config opencv --cflags --libs' -lopencv_gpu -lopencv_core
g++ -L/usr/local/lib -o main gpu_thresh.cpp 'pkg-config opencv --cflags --libs' -lopencv_gpu -lopencv_core
I tried to compile it with these ways but still giving same warning and error.
/usr/bin/ld: warning: libopencv_core.so.2.4, needed by
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/libopencv_gpu.so,
may conflict with libopencv_core.so.3.3 /usr/bin/ld: /tmp/ccdhLGL0.o:
undefined reference to symbol '_ZN2cv3gpu6GpuMat7releaseEv'
//usr/lib/x86_64-linux-gnu/libopencv_core.so.2.4: error adding
symbols: DSO missing from command line collect2: error: ld returned 1
exit status
What should I do?
There's no opencv2/gpu/gpu.hpp in OpenCV 3.3. If your code compiles then it means that you've both OpenCV 2.4 and 3.3 on your machine.
In OpenCV 3.3, include:
#include <opencv2/core/cuda.hpp>
and then use
cv::cuda::GpuMat img;
See details here.
Edit: I just noticed your compilation method. When using pkg-config opencv --cflags --libs, you don't need to manually add the libopencv files anymore.
Just do: g++ -o main gpu_thresh.cpp 'pkg-config opencv --cflags --libs'
I have an OpenSUSE 13.2 System with Qt5 and OpenCV installed with cudasupport. The Hardware is an Intel i5 processor with an integrated intel gpu chip and a NVidia GForce 940 M and i have tried to compile this file.
#include <iostream>
#include <time.h>
#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/opencv.hpp"
#include "opencv2/gpu/gpu.hpp"
using namespace std;
int main()
{
try
{
cv::Mat dst_mat;
cv::Mat src_host = cv::imread("/home/peter/testCuda/testCuda/GothaOrangerie.JPG", CV_LOAD_IMAGE_GRAYSCALE);
cv::namedWindow("Result",cv::WINDOW_NORMAL);
cv::imshow("Result", src_host);
cv::waitKey();
cv::gpu::GpuMat dst, src;
src.upload(src_host);
clock_t t = clock();
cv::gpu::threshold(src, dst, 128.0, 255.0, CV_THRESH_BINARY);
t = clock() -t;
cv::Mat result_host(dst);
cout << ((float)t)/CLOCKS_PER_SEC << endl;
cv::imshow("Result", result_host);
cv::waitKey();
t = clock();
cv::threshold(src_host, dst_mat, 128.0, 255.0, CV_THRESH_BINARY);
t = clock() -t;
cout << ((float)t)/CLOCKS_PER_SEC << endl;
cv::imshow("Result", dst_mat);
cv::waitKey();
}
catch(const cv::Exception& ex)
{
cout << "Error: " << ex.what() << endl;
}
return 0;
}
The compilation in the shell with
g++ main.cpp -o threshold `pkg-config --cflags --libs opencv` -lopencv_gpu -L/usr/local/cuda-7.5/lib64
works pretty well i can run the small program without any issues. If i try it with the Qt5 IDE it returns me this error.
OpenCV Error: No GPU support (The library is compiled without CUDA support) in mallocPitch, file /home/abuild/rpmbuild/BUILD/opencv-2.4.9/modules/dynamicuda/include/opencv2/dynamicuda/dynamicuda.hpp, line 126
Error: /home/abuild/rpmbuild/BUILD/opencv-2.4.9/modules/dynamicuda/include/opencv2/dynamicuda/dynamicuda.hpp:126: error: (-216) The library is compiled without CUDA support in function mallocPitch
If i run the shellcompiled program with this command
optirun ./threshold
i get the same error.
The .pro File is
#-------------------------------------------------
#
# Project created by QtCreator 2015-10-15T04:02:07
#
#-------------------------------------------------
TARGET = testCuda
LIBS += -L/usr/lib64/
LIBS += -L/usr/local/cuda-7.5/lib64 -lopencv_gpu
LIBS += `pkg-config opencv --cflags --libs`
SOURCES += main.cpp
and the Qt compilation command is
22:58:12: Running steps for project testCuda...
22:58:12: Configuration unchanged, skipping qmake step.
22:58:12: Starting: "/usr/bin/make"
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I../testCuda -I/usr/include/QtCore -I/usr/include/QtGui -I/usr/include -I. -I../testCuda -I. -o main.o ../testCuda/main.cpp
g++ -Wl,-O1 -o testCuda main.o -L/usr/lib64 -L/usr/lib64/ -L/usr/local/cuda-7.5/lib64 -lopencv_gpu `pkg-config opencv --cflags --libs` -lQtGui -L/usr/lib64 -L/usr/X11R6/lib -lQtCore -lpthread
22:58:13: The process "/usr/bin/make" exited normally.
22:58:13: Elapsed time: 00:01.
Anybody an idea how to fix that?
Deinstalling the preinstalled libopencv-2.4.9 package solved it.
EDIT
Hey,
For anyone else having a similar issue, I figured something of a work around out. If you just compile this using :
gcc `pkg-config --cflags opencv` CameraMotionTest.cpp `pkg-config --libs opencv` -o cammotion
instead of the makefile that I used, it compiles correctly. I'm not exactly sure what was wrong with the method I was using before still so if someone still wants to comment on that go ahead.
After doing this i found some other issues in the code that needed fixed as well but those didn't have anything to do with this question so I won't go into them here.
Thanks!
ORIGINAL
I am trying to compile a short code for camera motion estimation on Ubuntu using openCV but am running into and "undefined reference" error for one of the openCV functions (and only one). The error I get when I try to compile is as follows:
g++ CameraMotionTest.cpp -lopencv_video -lopencv_calib3d -lopencv_imgproc -lopencv_objdetect -lopencv_features2d -lopencv_core -lopencv_highgui -lopencv_videostab -lopencv_contrib -lopencv_flann -lopencv_legacy -lopencv_ml -lopencv_nonfree -lopencv_photo -lopencv_stitching -lopencv_superres -lopencv_ts -lopencv_gpu -lopencv_ocl -o CameraMotion
/tmp/ccdHB3Pr.o: In function `main':
CameraMotionTest.cpp:(.text+0x77f): undefined reference to `cv::calcOpticalFlowPyrLK(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray
const&, cv::_OutputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, cv::Size_<int>, int, cv::TermCriteria, int, double)'
collect2: ld returned 1 exit status
make: *** [CameraMotion] Error 1
I am using this makefile to try and compile and run the program:
all: run
run: CameraMotion
./CameraMotion *.jpg
CameraMotion: CameraMotionTest.cpp
g++ CameraMotionTest.cpp -lopencv_video -lopencv_calib3d -lopencv_imgproc -lopencv_objdetect -lopencv_features2d -lopencv_core -lopencv_highgui -lopencv_videostab -lopencv_contrib -lopencv_flann -lopencv_legacy -lopencv_ml -lopencv_nonfree -lopencv_photo -lopencv_stitching -lopencv_superres -lopencv_ts -lopencv_gpu -lopencv_ocl -o CameraMotion
Finally, the code I am trying to compile is:
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/video/tracking.hpp>
#include <opencv/cv.h>
#include <opencv/cxcore.h>
#include <iostream>
#include <stdio.h>
#include <fstream>
using namespace std;
using namespace cv;
int main(int argc, const char** argv){
//storing the image in a temporary variable
vector<Mat> img;
int noi=5;
for( int index=0; index<noi;index++){
img.push_back(imread(argv[index+1]));
}
Mat im1=img[0];
//converting image to grayscale
cvtColor(im1,im1,CV_RGB2GRAY);
//initializing variable
vector<Point2f> corners1, corners2;
//setting parameters for corner detection
int maxCorner=200;
double quality=0.01;
double minDist=20;
int blockSize=3;
double k=0.04;
Mat mask;
vector<uchar> status;
vector<float> track_err;
int maxlevel=3;
Mat im2=img[1];
TermCriteria termcrit(CV_TERMCRIT_ITER | CV_TERMCRIT_EPS,20,.03);
vector<Point2f> pointskept1,pointskept2;
vector<int>pointskeptindex;
Mat F,E,R,tran;
Matx33d W(0,-1,0,
1,0,0,
0,0,1);
Matx33d Winv(0,1,0,
-1,0,0,
0,0,1);
OutputArray statF=noArray();
float fx=951.302687761842550;
float fy=951.135570101293520;
float cx=484.046807724895250;
float cy=356.325026020307800;
float alpha=0;
float kmatdata[3][3]={{fx,fy*tan(alpha),cx},{0,fy,cy},{0,0,1}};
Mat K(3,3,CV_32FC1,kmatdata);
cout<<K<<endl;
ofstream myfile;
//collecting new images, determining corners, and calculating optical flow
for (int i=1; i<noi-1; i++) {
//capturing next image
//converting new image to grayscale
cvtColor(im2,im2,CV_RGB2GRAY);
//determining corner features
goodFeaturesToTrack(im1,corners1, maxCorner, quality, minDist, mask, blockSize, false,k);
goodFeaturesToTrack(im2,corners2, maxCorner, quality, minDist, mask, blockSize, false,k);
//calculating optical flow
calcOpticalFlowPyrLK(im1,im2,corners1,corners2,status,track_err,Size(10,10),maxlevel,termcrit,0.0001);
//filtering points
for(int t=0; t<status.size();i++){
if(status[t] && track_err[i]<12.0){
pointskeptindex.push_back(i);
pointskept1.push_back(corners1[i]);
pointskept2.push_back(corners2[i]);
} else {
status[i]=0;
}
}
F=findFundamentalMat(pointskept1,pointskept2,FM_RANSAC,1,0.99,statF);
E=K.t()*F*K;
SVD svd(E);
R=svd.u*Mat(W)*svd.vt;
tran=svd.u.col(2);
//renaming new image to image 1
im2.copyTo(im1);
im2=img[i+1];
myfile.open("output.txt", ios_base::app);
myfile<<"Rotation mat: ";
for(int l=0;l<R.rows;l++){
for(int m=0; m<R.cols; m++){
myfile<<R.at<float>(i,m)<<", ";
}
}
myfile<<"Translation vector: ";
for(int l=0; l<tran.rows;l++){
myfile<<tran.at<float>(l,1)<<", ";
}
myfile<<"\n";
myfile.close();
}
return 0;
}
Has anyone else run into a problem like this? I am assuming that there is just a linking error somewhere but I am quite frankly pretty new to opencv and c++ in general and i haven't been able to figure out what is wrong yet.
Thanks!
Andrew
For anyone else having a similar issue, I figured something of a work around out. If you just compile this using :
gcc `pkg-config --cflags opencv` CameraMotionTest.cpp `pkg-config --libs opencv` -o cammotion
instead of the makefile that I used, it compiles correctly. I'm not exactly sure what was wrong with the method I was using before still so if someone still wants to comment on that go ahead.
After doing this i found some other issues in the code that needed fixed as well but those didn't have anything to do with this question so I won't go into them here.
Thanks!
It seems that You have some problem with Your OpenCV instalation. To compile Your code, on OpenCV 2.4.9, it was enough to use
g++ t1.cpp -lopencv_video -lopencv_core -lopencv_objdetect -lopencv_imgproc -lopencv_highgui -lopencv_calib3d -o CameraMotion
You can also try using nm -g <library> | grep -i <function_name> to check if Your libopencv_video.so contains calcOpticalFlowPyrLK... (based on this answer).
I am working on getting a few files to link together using my make file and c++ and am getting the following error when running make.
g++ -bind_at_load `pkg-config --cflags opencv` -c -o compute_gist.o compute_gist.cpp
g++ -bind_at_load `pkg-config --cflags opencv` -c -o gist.o gist.cpp
g++ -bind_at_load `pkg-config --cflags opencv` -c -o standalone_image.o standalone_image.cpp
g++ -bind_at_load `pkg-config --cflags opencv` -c -o IplImageConverter.o IplImageConverter.cpp
g++ -bind_at_load `pkg-config --cflags opencv` -c -o GistCalculator.o GistCalculator.cpp
g++ -bind_at_load `pkg-config --cflags opencv` `pkg-config --libs opencv` compute_gist.o gist.o standalone_image.o IplImageConverter.o GistCalculator.o -o rungist
Undefined symbols for architecture x86_64:
"color_gist_scaletab(color_image_t*, int, int, int const*)", referenced from:
_main in compute_gist.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
make: *** [rungist] Error 1
My makefile is as follows (Note, I don't need opencv bindings yet, but will be coding in opencv later.
CXX = g++
CXXFLAGS = -bind_at_load `pkg-config --cflags opencv`
LFLAGS = `pkg-config --libs opencv`
SRC = \
compute_gist.cpp \
gist.cpp \
standalone_image.cpp \
IplImageConverter.cpp \
GistCalculator.cpp
OBJS = $(SRC:.cpp=.o)
rungist: $(OBJS)
$(CXX) $(CXXFLAGS) $(LFLAGS) $(OBJS) -o $#
all: rungist
clean:
rm -rf $(OBJS) rungist
The method header is located in gist.h
float *color_gist_scaletab(color_image_t *src, int nblocks, int n_scale, const int *n_orientations);
And the method is defined in gist.cpp
float *color_gist_scaletab(color_image_t *src, int w, int n_scale, const int *n_orientation) {
And finally the compute_gist.cpp (main file)
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "gist.h"
static color_image_t *load_ppm(const char *fname) {
FILE *f=fopen(fname,"r");
if(!f) {
perror("could not open infile");
exit(1);
}
int width,height,maxval;
if(fscanf(f,"P6 %d %d %d",&width,&height,&maxval)!=3 || maxval!=255) {
fprintf(stderr,"Error: input not a raw PPM with maxval 255\n");
exit(1);
}
fgetc(f); /* eat the newline */
color_image_t *im=color_image_new(width,height);
int i;
for(i=0;i<width*height;i++) {
im->c1[i]=fgetc(f);
im->c2[i]=fgetc(f);
im->c3[i]=fgetc(f);
}
fclose(f);
return im;
}
static void usage(void) {
fprintf(stderr,"compute_gist options... [infilename]\n"
"infile is a PPM raw file\n"
"options:\n"
"[-nblocks nb] use a grid of nb*nb cells (default 4)\n"
"[-orientationsPerScale o_1,..,o_n] use n scales and compute o_i orientations for scale i\n"
);
exit(1);
}
int main(int argc,char **args) {
const char *infilename="/dev/stdin";
int nblocks=4;
int n_scale=3;
int orientations_per_scale[50]={8,8,4};
while(*++args) {
const char *a=*args;
if(!strcmp(a,"-h")) usage();
else if(!strcmp(a,"-nblocks")) {
if(!sscanf(*++args,"%d",&nblocks)) {
fprintf(stderr,"could not parse %s argument",a);
usage();
}
} else if(!strcmp(a,"-orientationsPerScale")) {
char *c;
n_scale=0;
for(c=strtok(*++args,",");c;c=strtok(NULL,",")) {
if(!sscanf(c,"%d",&orientations_per_scale[n_scale++])) {
fprintf(stderr,"could not parse %s argument",a);
usage();
}
}
} else {
infilename=a;
}
}
color_image_t *im=load_ppm(infilename);
//Here's the method call -> :(
float *desc=color_gist_scaletab(im,nblocks,n_scale,orientations_per_scale);
int i;
int descsize=0;
//compute descriptor size
for(i=0;i<n_scale;i++)
descsize+=nblocks*nblocks*orientations_per_scale[i];
descsize*=3; // color
//print descriptor
for(i=0;i<descsize;i++)
printf("%.4f ",desc[i]);
printf("\n");
free(desc);
color_image_delete(im);
return 0;
}
Any help would be greatly appreciated. I hope this is enough info. Let me know if I need to add more.
I suspect that color_gist_scaletab should be declared as extern "C" in your header file:
extern "C" {
float *color_gist_scaletab(color_image_t *src, int nblocks, int n_scale, const int *n_orientations);
}
Your link command line is incorrect. See this answer.
However, that is likely not the problem you are seeing here.
What do the following commands print?
file gist.o
nm gist.o | grep color_gist_scaletab
I also see this very similar question. But there, color_gist_scaletab comes from gist.c, not gist.cpp. You didn't just rename gist.c to gist.cpp, did you? Don't do that.