You need to add the OpenCV jar as a user library in build.properties, it won't work if you only add it as a normal Eclipse dependency.
The easiest way to do it is to put the jar in ${user.home}/wpilib/user/lib (for you, C:\Users\2472\wpilib\user\lib\opencv-java-3.1.0.jar) and add
that jar as an Eclipse dependency
Your build.properties file should then have the line
Code:
userLibs=${user.home}/wpilib/user/lib/opencv-java-3.1.0.jar
Note that I'm referencing WPILib's build of OpenCV (which can be found
here) which doesn't contain any compiled native libraries.