How do I setup opencv2 on my ubuntu distribution

baronobeefdip · 09-19-2015, 03:23 PM

I have a project to do but I need opencv libraries in order to do it. I did the apt-get install commands and tried to compile the c++ file that was given to me but I got a bunch of errors. I think the libraraies are not there, or they are placed in a location that the compiler doesn't seem to be looking in. where is the compiler looking for these library files and how do I set to where the compiler will include these files when it compiles a program.

norobro · 09-19-2015, 05:27 PM

Quote:

Originally Posted by baronobeefdip

I did the apt-get install commands

Did you install the development package?

Code:

$ apt-get install opencv-dev

EDIT: As noted by baronofbeefdip below that should be libopencv-dev

Quote:

Originally Posted by baronobeefdip

. . . I got a bunch of errors.

Please list the errors.

Here's an example command line to compile a c++/opencv program on my system:

Code:

g++ -std=c++11 main.cpp -lstdc++ $(pkg-config --libs --cflags opencv)

baronobeefdip · 09-19-2015, 05:28 PM

Quote:

Originally Posted by norobro

Did you install the development package?

Code:

$ apt-get install opencv-dev

Please list the errors.

Here's an example command line to compile a c++/opencv program on my system:

Code:

g++ -std=c++11 main.cpp -lstdc++ $(pkg-config --libs --cflags opencv)

The errors are pretty much saying that they can't find the header files.

Just tried your apt-get command and I got an error, is there a ppa or something that I can use to fix this one.

Code:

E: Unable to locate package opencv-dev

baronobeefdip · 09-19-2015, 05:34 PM

Quote:

Originally Posted by norobro

Did you install the development package?

Code:

$ apt-get install opencv-dev

Please list the errors.

Here's an example command line to compile a c++/opencv program on my system:

Code:

g++ -std=c++11 main.cpp -lstdc++ $(pkg-config --libs --cflags opencv)

I just ran this command and installed all of the development files, I'll post what happens when I try to compile the program

Code:

apt-get install libopencv-dev

norobro · 09-19-2015, 05:36 PM

EDIT: whoops, had this open in a tab and missed your post.

Are you still on Squeeze? What do you use as repositories?

Here is opencv-dev in Wheezy: link

baronobeefdip · 09-19-2015, 05:38 PM

Quote:

Originally Posted by norobro

Are you still on Squeeze? What do you use as repositories?

Here is opencv-dev in Wheezy: link

I just tried to compile the program, here is what came back

Code:

/tmp/ccvvzxBm.o: In function `main':
lab1.cpp:(.text+0x5c): undefined reference to `cv::imread(std::string const&, int)'
lab1.cpp:(.text+0x1a9): undefined reference to `cv::namedWindow(std::string const&, int)'
lab1.cpp:(.text+0x1da): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
lab1.cpp:(.text+0x21a): undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
lab1.cpp:(.text+0x242): undefined reference to `cv::waitKey(int)'
lab1.cpp:(.text+0x275): undefined reference to `cv::destroyWindow(std::string const&)'
/tmp/ccvvzxBm.o: In function `cv::Mat::~Mat()':
lab1.cpp:(.text._ZN2cv3MatD2Ev[_ZN2cv3MatD5Ev]+0x39): undefined reference to `cv::fastFree(void*)'
/tmp/ccvvzxBm.o: In function `cv::Mat::operator=(cv::Mat const&)':
lab1.cpp:(.text._ZN2cv3MataSERKS0_[_ZN2cv3MataSERKS0_]+0x111): undefined reference to `cv::Mat::copySize(cv::Mat const&)'
/tmp/ccvvzxBm.o: In function `cv::Mat::release()':
lab1.cpp:(.text._ZN2cv3Mat7releaseEv[_ZN2cv3Mat7releaseEv]+0x47): undefined reference to `cv::Mat::deallocate()'
collect2: error: ld returned 1 exit status

I am using Backbox Linux, the most recent reccomended version.

norobro · 09-19-2015, 05:43 PM

And how did you compile it? Are you using an IDE?

baronobeefdip · 09-19-2015, 05:47 PM

Quote:

Originally Posted by norobro

And how did you compile it? Are you using an IDE?

I used the g++ command, I figured because it was a C++ file.

norobro · 09-19-2015, 05:57 PM

What do you get with the following command?

Code:

pkg-config --libs opencv

baronobeefdip · 09-19-2015, 06:01 PM

Code:

/usr/lib/x86_64-linux-gnu/libopencv_calib3d.so /usr/lib/x86_64-linux-gnu/libopencv_contrib.so /usr/lib/x86_64-linux-gnu/libopencv_core.so /usr/lib/x86_64-linux-gnu/libopencv_features2d.so /usr/lib/x86_64-linux-gnu/libopencv_flann.so /usr/lib/x86_64-linux-gnu/libopencv_gpu.so /usr/lib/x86_64-linux-gnu/libopencv_highgui.so /usr/lib/x86_64-linux-gnu/libopencv_imgproc.so /usr/lib/x86_64-linux-gnu/libopencv_legacy.so /usr/lib/x86_64-linux-gnu/libopencv_ml.so /usr/lib/x86_64-linux-gnu/libopencv_objdetect.so /usr/lib/x86_64-linux-gnu/libopencv_ocl.so /usr/lib/x86_64-linux-gnu/libopencv_photo.so /usr/lib/x86_64-linux-gnu/libopencv_stitching.so /usr/lib/x86_64-linux-gnu/libopencv_superres.so /usr/lib/x86_64-linux-gnu/libopencv_ts.so /usr/lib/x86_64-linux-gnu/libopencv_video.so /usr/lib/x86_64-linux-gnu/libopencv_videostab.so -lopencv_calib3d -lopencv_contrib -lopencv_core -lopencv_features2d -lopencv_flann -lopencv_gpu -lopencv_highgui -lopencv_imgproc -lopencv_legacy -lopencv_ml -lopencv_objdetect -lopencv_ocl -lopencv_photo -lopencv_stitching -lopencv_superres -lopencv_ts -lopencv_video -lopencv_videostab

norobro · 09-19-2015, 06:15 PM

That's the same list my system has. Is your c++ file too large to post?

baronobeefdip · 09-19-2015, 06:25 PM

not at all

Code:

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>
 
using namespace cv;
using namespace std;

int main( )
{
      Mat img;

      img = imread("tamucc.jpg", CV_LOAD_IMAGE_UNCHANGED); //read the image data in the file "tamucc.jpg" and store it in 'img'


    if (img.empty()) //check whether the image is loaded or not
     {
          cout << "Error : Image cannot be loaded..!!" << endl;
         
          return -1;
     } 

double rows = img.rows; // image size
double cols = img.cols;


cout<< "The image has "<<rows<<" rows and "<<cols << " columns"<<endl;

     namedWindow("MyWindow",CV_WINDOW_NORMAL);
    imshow("MyWindow", img); //display the image which is stored in the 'img' in the "MyWindow" window

    waitKey(0); //wait infinite time for a keypress

    destroyWindow("MyWindow"); //destroy the window with the name, "MyWindow"


     return 0;
}

norobro · 09-19-2015, 06:47 PM

Works on my box, of course with a different jpeg file:

Code:

$ gcc -std=c++11 main.cpp  -lstdc++  $(pkg-config --libs --cflags opencv)
$ ./a.out 
The image has 389 rows and 600 columns

So something is wrong with your install. Maybe try reinstalling opencv?

Is the tamucc what i think it is? I'm in central Tejas.

baronobeefdip · 09-19-2015, 06:56 PM

How do I reinstall it, because it's a fresh Linux distribution installation and a fresh install of opencv. I didn't do anything with anything on the system other than install the opencv development files.

norobro · 09-19-2015, 07:11 PM

The only way I know is to remove the package first and the install it again. Probably not necessary though.

What does the following output? As root:

Code:

ldconfig -p | grep opencv