Hi Guanta; Thanks for your suggestions. I have tried them but unfortunately I ended up with the same "not declared in this scope" errors. I have gone as far as having modified each include statement to reflect the actual include address i.e.: #include "/usr/local/include/opencv2/<include filename>" but again without any change to the make errors.

I forgot to let you know that I did a "cmake ./" which did printout correctly the location of the opencv libraries, and complete without any errors, I followed by a "make".

Any further suggestions. Grahame

Do you actually use the correct functions and namespace? E.g. it is cv::imread("path") not imread("path") and so on (you can omit the namespace if you write at the beginning using namespace cv;

I am sure I have correct name-space.

Herein is the test program in full (excluding the #include statements as there is not enough room to fit here).

gmk@Brushtail:~/test3$ cat test3.cpp

// From top-of-page Page 17 of the OpenCV book

using namespace cv;

include "my_includes.hpp"

int main(int argc, char** argv) {

IplImage* img = loadImage( argv[1] );

namedWindow( "Test3-Example1", CV_WINDOW_AUTOSIZE );
showImage( "Test3-Example1", img );
waitKey(0);
releaseImage( &img );
destroyWindow( "Test3-Example1" );
return 0;

}

In "my_include.hpp" header file I have all header files from opencv and opencv2, in an effort to over these problems.

Maybe I need to load/run OpenCV on a different Linux distribution (currently Ubuntu 12.04.2 LTS). Any further thoughts?

Don't worry about your system. OpenCV 2.4.5 should work with no problem. Can you please try:

int main(int argc, char* argv) { cv::Mat img = cv::imread(argv[1]); cv::imshow( "Test3-Example1", img ); cv::waitKey(0); return 0; }

with the includes as in my first post.

[100%] Building CXX object CMakeFiles/test3.dir/test3.cpp.o Linking CXX executable test3 [100%] Built target test3

It all compiled and more importantly Linked includes correctly.

Is this a bug?

./test3 ../cat.jpg read correctly without problems.

Thanks for your sustained help. G.

You are welcome! Great I could help. Please mark the answer as correct, so that it appears solved.

Before I mark this as answered, what do I do with the original cv::calls such as showImage, loadImage, releaseImage which exists in the documentation but I am unable to get its header file to play ball? My original problem with the examples, not correlating with the header files still stands.

As I am new here, how do I mark a answer as correct?

You have to differentiate between C and C++. I recomment to stick to the C++ functionality and use these calls since current development is working at C++. You can however compile the C examples, too with gcc or by marking the headers of the C-library as extern "C" (http://stackoverflow.com/questions/1041866/in-c-source-what-is-the-effect-of-extern-c) . You can mark an answer as correct by clicking on the small hook below the voting-number (if you hover your mouse above it, it will also tell you that) - see also the FAQ: http://answers.opencv.org/faq.