I'm trying to recognize rectangular boxes using Kinect, I know I can use OpenCV or PCL to do this but my C++ is a bit rusty, I'm new to Computer Vision in 3D and I want to do it as quick as possible, it's only a demo for a bigger project.
Is there anyway to do it using C# or at least Python, I don't care if I have to learn 3D.
If not, which library should I use, OpenCV or PCL?
I recommend OpenCV.
If you want to work in C# or python with OpenCV then you have wrappers for both of them:
http://www.emgu.com/wiki/index.php/Main_Page
http://www.neuroforge.co.uk/index.php/getting-started-with-python-a-opencv