Assuming you're trying to look at contours on the driver station while GRIP is deployed, I'm working on a SmartDashboard plugin for GRIP that should do something similar to this.
https://github.com/WPIRoboticsProjec...SmartDashboard
It gets feature data from NetworkTables and images from GRIP's "Publish Video" operation. Unlike SmartDashboard's built-in USB Camera viewer, it should work if GRIP is running on either the roboRIO or a coprocessor, since there's an option to set the address.
It doesn't have support for rendering contours yet, but it's on the way.