Hi,
we're a team of experienced programmers very well versed in python. I've gone through your requirement. we're sure of completing this efficiently and on time.
we can proceed with openCV for image processing and PyQt or Tkinter or pygame for GUI.
Also, I've raspberry pi 2 to test this.
I've a question.. what platform are you using on raspberry? is it raspbian or windows 10 or any other system?
If you're interested, we can further discuss this via messages.
Thanks,
PS -- Do read our reviews.