Object detection slow and doesn't use GPU

System information

• What is the top-level directory of the model you are using: object_detection
• Have I written custom code (as opposed to using a stock example script provided in TensorFlow): No
• OS Platform and Distribution (e.g., Linux Ubuntu 16.04): Windows 7, Ubuntu 16.04
• TensorFlow installed from (source or binary): pip
• TensorFlow version (use command below): 1.12, 1.14
• Bazel version (if compiling from source):
• CUDA/cuDNN version: 9.0, 10.0 / 7.4.2.24, 7.6
• GPU model and memory: GTX 970, 4GB
• Exact command to reproduce:

Describe the problem

Hi,
my problem is that when using pretrained coco model from the tutorial delivered with object detection API, the detection on exemplary pictures takes too much time. I checked the GPU usage and it does not move at all, instead CPU is used. My tensorflow-GPU installation should be OK, since I use it with different scripts and it works well. I tried installing it on Ubuntu 16.04 and it was the same. I tried different CUDA Toolkit, CUDNN versions and TF versions (mentioned in the System Information section) and still nothing (CuDNN 7.05 didn't work due to another error problem, fixed by using newer versions). My project however requires faster detection time.