TensorFlow Object Detection

Posted October 25, 2018 by Rokas Balsys

TensorFlow Object Detection Introduction

The purpose of this tutorial is to learn how to install and prepare TensorFlow framework to train your own convolutional neural network object detection classifier for multiple objects, starting from scratch. At the end of this tutorial, you will have basics and a program that can identify and draw boxes around specific objects in computer screen.

There are several good tutorials available for how to use TensorFlow’s Object Detection API to train a classifier for a single or several objects, but they are not that detailed how we want they to be. More over Object Detection API seems to have been developed on a Linux-based OS. To set up TensorFlow to train and use a model on Windows, there are several workarounds that need to be used in place of commands that would work fine on Linux. Also, this tutorial provides instructions for training a classifier that can detect multiple objects, not just one.

This tutorial is written and tested for Windows 10 operating system, it should also work for Windows 7 and 8, but haven’t tested that, so I am not sure. The general procedure can also be used for Linux operating systems, but file paths and package installation commands should be changed accordingly.

TensorFlow-GPU allows your PC to use the video card to provide extra processing power while training, so it will be used for this tutorial. In my experience, using TensorFlow-GPU instead of regular TensorFlow reduces training time by a factor of about 8 (depends on used CPU and trained model).

Regular CPU version TensorFlow can also be used for this tutorial, but it will take longer and real time models may work slower. If you use regular TensorFlow, you do not need to install CUDA and cuDNN in installation step. I used newest TensorFlow-GPU v1.11 while creating this tutorial, but it also should work for future versions of TensorFlow, but I am not guaranteed.

Vision of this tutorial: to create TensorFlow object detection model, that could detect CS:GO players. In this tutorial we’ll be more focused on detecting terrorists and counter terrorists bodies and heads, then automatically aim to them and shoot. At first, it seems like an easy task, but going through this tutorial series you will see that there is more problems than it seems.

Main computer specs for this tutorial:

  • OS – Windows 10 Pro
  • GPU - GTX1080TI
  • CPU – i5-6400
  • RAM – 16GB
TensorFlow-GPU 1.11, CUDA v9.0, cuDNN v7.3.1 installation

Hardware requirements:

  • NVIDIA® GPU card with CUDA® Compute Capability 3.5 or higher
  • Strong enough computer (high end CPU and at least 8GB of RAM)

Software requirements:

In many places there was said that there is some problems while working on newest CUDA versions, but I took this challenge and installed CUDA v10.0 and cuDNN v7.3.1. As future versions of TensorFlow will be released, you will likely need to continue updating the CUDA and cuDNN versions to the latest supported version. If you face problems while installing CUDA, visit this documentation site. If you face problems while installing cuDNN, visit this documentation site. This tutorial is made for TensorFlow-GPU v1.11, so the “pip install tensorflow-gpu” command should automatically download and install newest 1.11 version.

Install Python 3.6 64-bit version and install all required packages

If you don’t know how to install python, follow my tutorial on this tutorial page. 32-bit version doesn’t support TensorFlow so don’t even try. If you already have python installed, install required packages:

pip install pillow
pip install lxml
pip install Cython
pip install jupyter
pip install matplotlib
pip install pandas
pip install opencv-python
pip install tensorflow-gpu
Set up TensorFlow Object Detection repository

Download the full TensorFlow object detection repository located at this link by clicking the "Clone or Download" button and downloading the zip file. Open the downloaded zip file and extract the "models-master" folder directly into the "C:\" directory. Rename "models-master" to "TensorFlow".

This working directory will contain the full TensorFlow object detection framework, as well as your training images, training data, trained classifier, configuration files, and everything else needed for the object detection classifier.

You can follow my tutorial with installation and repository preparation or follow original TensorFlow tutorial (Must mention it didn’t worked for me with official tutorial).

When you already have TensorFlow models on your disk, you must add object detection directories to python path (if it doesn’t work from CMD line, do it manually like I did on video tutorial):

Configure PYTHONPATH environment variable (I reccoment do it manyally as I did in video tutorial):

set PYTHONPATH=$PYTHONPATH;C:\TensorFlow\research
set PYTHONPATH=$PYTHONPATH;C:\TensorFlow\research\slim

Next, compile the Protobuf files, which are used by TensorFlow to configure model and training parameters. Unfortunately, the short protoc compilation command posted on TensorFlow’s Object Detection API installation page doesn’t work for me on Windows. So I downloaded older 3.4.0 version of protoc from here. Transfered files to same TensorFlow directory and ran the following command from the tensorflow /research/ directory:

# From tensorflow/research/
"C:/TensorFlow/bin/protoc" object_detection/protos/*.proto --python_out=.

Finally, run the following command from the C:\TensorFlow\research directory:

# From tensorflow/research/
python setup.py install

You can test that you have correctly installed the Tensorflow Object Detection API by running the following command:

# From tensorflow/research/object_detection
python builders/model_builder_test.py

If everything was fine you can test it out and verify your installation is working by launching the object_detection_tutorial.ipynb script with Jupyter. From the object_detection directory, issue this command:

# From tensorflow/research/object_detection
jupyter notebook

In your browser click on „object_detection_tutorial.ipynb“. Then navigate to „Cell“ in navigation bar and click on „Run All“. If everything is fine in short time you should see these nice photos:

Dog image Kite image

In this short tutorial we learned what we need to download, files to get and rename to install TensorFlow object detection API. In the end we have prepared our files for further object detection tutorials.