How to resolve an error: imread is not a member of cv?

Question

I use OpenCV 3.0 and Ubuntu 14.04. I'm trying to compile a few codes on Ubuntu using OpenCV. I get error

"error: 'imread' is not a member of 'cv'"

Due to my previous search knowledge, I tried compiling by adding "highgui.h".

I use:

$g++ main.cpp HOG.cpp HOGFeaturesOfBlock.cpp -I/usr/local/include/opencv -lml -lcvaux -highgui -lcv -lcxcore -o featureExtractor

on the terminal to compile.

Any suggestions?

Targett

Please post an minimal reproducible example so we can see exactly what you've done - otherwise it's hard to answer. – Kalinda

You have not set OpenCV correctly. See here to know what to include and link (here are added to a Visual Studio project, just add to you gcc command line). – Lillian

Okay, I'm trying to extract features form depth images in main.cpp I have also readData.cpp which is invoked in main. cpp in which I used imread when I tried to compile I get readData.cpp:error: 'imread' is not a member of 'cv' – Targett

@Lillian I use Ubuntu, not Windows :/ – Targett

Yeah, I got that. But you need to include and link opencv properly. – Lillian

in opencv3 afaik imread isnt part of highgui anymore. try to find the right module or include the all-in-one-header, opencv.hpp or similar – Racialism

Check out here @berriel did a nice tutorial. – Lillian

Just add this header file #include "opencv2/highgui/highgui.hpp" – Trash

Answer 1

The following commands should work. If it doesn't work you should check if you set the include/lib files correctly.

#include <opencv2\highgui\highgui.hpp>
#include <opencv2\core\core.hpp>
#include <opencv\cv.hpp>

using namespace cv;

Mat image = imread(filename, CV_LOAD_IMAGE_COLOR);

Centiliter

1) you don't need #include <opencv\cv.hpp>, 2) you can just use #include <opencv2/opencv.hpp> 3) without a main this won't work, 4) Opencv 3.0 parameter is now called IMREAD_COLOR – Lillian

I included those headers to my code, but this time I get another error, /usr/bin/ld cannot find -lml and same error for other libraries – Targett

Answer 2

#include <opencv2/imgcodecs.hpp> 

solved the problem which contains the imread function

Heraldry

Answer 3

I found that the compile command had to be very specific (besides having added using namespace cv; in the code), with the source file having to come directly after the g++, as follows;

g++ test.cpp -fpermissive $(pkg-config --cflags --libs opencv) -o testbin

Replace opencv with opencv4 if that is what you use

Waltman

Answer 4

I had a same question before. Just add #include "imgcodec.hpp", Hope this can help you

Horrified