Thursday, February 4, 2010

Setting up OpenCV in Eclipse on Windows


Recently OpenCV 2.0 was officially released. For those looking to do an upgrade to 2.0 (OR LATER) or installing OpenCV for the first time, there are some discrepancies with how older sites say you should setup your environment. I did some file digging and this is what I found works:

First download and setup the basics:
  • Get MinGW
  • Download Eclipse C/C++ IDE
Note: I have a tutorial on these two steps already so just head over HERE for more info.

  • Next download/install OpenCV 2.0 (OR download a more recent version)
  • Now launch Eclipse and start a new project by going to:
  1. File->New->C++ Project (or File->New->C Project)
  2. Give your project a name in the "Project name" box
  3. Select the "Hello World" option under the "Project Type" section under the "Executable" folder. I recommend this over the "Empty Project" as it creates the c/c++ file for you instead of having to do it manually (it also creates a "src" folder and a "Debug" folder which helps keep things a little more organized)
  4. Make sure the "MinGW" Toolchain is selected in the "Toolchains" section
  5. Hit NEXT
  6. Fill in your Author and other file information, then hit NEXT
  7. In the next window select "Advanced settings...". This will bring you to the "Project Settings" which can always be accessed later by going to Project->Properties
  8. Under the "C/C++ Build" Section go to the "Settings" and select the "Tool Settings" Tab. Then select the "Includes" folder (on older versions of eclipse it is the "Directories" folder) in the GCC Compiler branch and add the opencv include directory to Include paths (-I): "C:\OpenCV2.0\include\opencv\". Of course, change C:\OpenCV2.0 to match the installed path that you used.
  9. Now, under the MinGW Linker select the "Libraries" folder and add the following to the Libraries (-l) section (note not all of these are necessarily needed for your project but these are all the libraries available in opencv):
  • cv200
  • cvaux200
  • cxcore200
  • cxts200
  • highgui200
  • ml200
In most cases you will only need cv200 and highgui200 to get started

ALSO NOTE: Versions 2.0 and later postfix the libraries names with a three digit number that corresponds to the version of OpenCV that you are linking to. Example: OpenCV2.1's highgui library must be linked using the name highgui210.

FINALLY, under the "Library search path (-L)" section add:
  • "C:\OpenCV2.0\lib"
  1. Hit OK when done
  2. Hit Finish to create and start the Project
Write up a simple program to test if opencv works properly. You can use this snippet of code I made to test if your video camera and environment are working properly. I would have posted the code here, but blogger is being very difficult with the c++ syntax (i.e. it is trying to read a lot of things as html tags).

If you get an error, during compile time, pertaining to:

Then visit this page and follow the instructions under:
Building on Windows using MinGW 3.4.5

Hope this helps!