some suggestion about to accelerate speed

[machanic]

some suggestion about to accelerate speed I found your data format is "NHWC" , but according to page : https://www.tensorflow.org/performance/performance_guide NHWC is the TensorFlow default and NCHW is the optimal format to use when training on NVIDIA GPUs using cuDNN. You should use NCHW as your CNN format, and your nms, ps roi pooling may also need change.

[machanic]

If you use GPU, you should always use NCHW