opencv - Build errors while following the instructions given on a website

Question

Hi i've tried following the instructions from this website http://robotica.unileon.es/mediawiki/index.php/Objects_recognition_and_position_calculation_(webcam)

At the part where they asked to add this :

find_package(OpenCV "VERSION" REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})
...
target_link_libraries("PROGRAM_NAME" ${OpenCV_LIBS})

i added and tried to build the package but it resulted in the errors:

Parse error.  Expected a command name, got unquoted argument with text "...".
-- Configuring incomplete, errors occurred!
make: *** [cmake_check_build_system] Error 1
Invoking "make cmake_check_build_system" failed

Could any one please help me resolve this error?

Answer 1

This basically describes how you're able to add OpenCV to your own program, if you're actually using CMake.

The text in quotes has to be replaced with your actual values/project names, for example, if my target is called myopencvthing and I'd want to use OpenCV 2.0 or newer, then I'd setup something like this:

# First tell CMake the minimal version of CMake expected
cmake_minimum_required(VERSION 2.8)

# Define a project
project(myopencvproject)

# Tell CMake to look for OpenCV 2.0 (and tell it that it's required, not optional)
find_package(OpenCV 2.0 REQUIRED)

# Tell CMake to add the OpenCV include directory for the preprocessor
include_directories(${OpenCV_INCLUDE_DIRS})

# Add the source files to a variable
set(SOURCES main.cpp processing.cpp somethingelse.cpp)

# Define the actual executable target and the source files
add_executable(myopencvthing ${SOURCES})

# Finally, add the dependencies of our executable (i.e. OpenCV):
target_link_libraries(myopencvthing ${OpenCV_LIBS})

Now you'll just have to run CMake to create your actual makefiles or project files and then build everything, e.g.:

cd /my/build/dir
cmake /path/to/my/source
make

If CMake fails to find the specified dependencies, then you'll have to open the CMakeCache.txt file and edit those paths by hand (or use cmake-gui in case you prefer a more visual editor).