Hello , First thank you for this great project !
I would like to know please if tensorflow use the GPu on the raspberry pi ?
Thanks for the question- unfortunately, at this time TensorFlow isn't compatible with the GPU on the Raspberry Pi, as TensorFlow only supports NVIDIA CUDA graphics cards.
One day (hopefully), a group of people will find a reasonable way to map OpenCL/CUDA calls onto the RPi GPU!
In the meantime, if you'd like to create custom deep learning code for the Raspberry Pi's GPU, a good place to get started is this post by Pete Warden.