/ssd.pytorch

A PyTorch Implementation of Single Shot MultiBox Detector

Primary LanguagePythonMIT LicenseMIT

SSD: Single Shot MultiBox Object Detector, in PyTorch

A PyTorch implementation of Single Shot MultiBox Detector from the 2016 paper by Wei Liu, Dragomir Anguelov, Dumitru Erhan, Christian Szegedy, Scott Reed, Cheng-Yang, and Alexander C. Berg. The official and original Caffe code can be found here.

Authors

Note: Unfortunately, this is just a hobby of ours and not a full-time job, so we'll do our best to keep things up to date, but no guarantees. That being said, thanks to everyone for your continued help and feedback as it is really appreciated. We will try to address everything as soon as possible.

Table of Contents

       

Installation

  • Install PyTorch by selecting your environment on the website and running the appropriate command.
  • Clone this repository.
    • Note: We currently only support Python 3+.
  • Then download the dataset by following the instructions below.
  • We now support Visdom for real-time loss visualization during training!
    • To use Visdom in the browser:
    # First install Python server and client 
pip install visdom
# Start the server (probably in a screen or tmux)
python -m visdom.server
    • Then (during training) navigate to http://localhost:8097/ (see the Train section below for training details).
  • Note: For training, we currently only support VOC, but are adding COCO and hopefully ImageNet soon.
  • UPDATE: We have switched from PIL Image support to cv2. The plan is to create a branch that uses PIL as well.

Datasets

To make things easy, we provide a simple VOC dataset loader that inherits torch.utils.data.Dataset making it fully compatible with the torchvision.datasets API.

VOC Dataset

Download VOC2007 trainval & test
# specify a directory for dataset to be downloaded into, else default is ~/data/
sh data/scripts/VOC2007.sh # <directory>
Download VOC2012 trainval
# specify a directory for dataset to be downloaded into, else default is ~/data/
sh data/scripts/VOC2012.sh # <directory>

Training SSD

mkdir weights
cd weights
wget https://s3.amazonaws.com/amdegroot-models/vgg16_reducedfc.pth
  • To train SSD using the train script simply specify the parameters listed in train.py as a flag or manually change them.
python train.py
  • Note:
    • For training, an NVIDIA GPU is strongly recommended for speed.
    • Currently we only support training on v2 (the newest version).
    • For instructions on Visdom usage/installation, see the Installation section.
    • You can pick-up training from a checkpoint by specifying the path as one of the training parameters (again, see train.py for options)

Evaluation

To evaluate a trained network:

python eval.py

You can specify the parameters listed in the eval.py file by flagging them or manually changing them.

Performance

VOC2007 Test

mAP
Original Converted weiliu89 weights From scratch w/o data aug From scratch w/ data aug
77.2 % 77.26 % 58.12% 77.43 %
Evaluation report for the current version

VOC07 metric? Yes

AP for aeroplane = 0.8172
AP for bicycle = 0.8544
AP for bird = 0.7571
AP for boat = 0.6958
AP for bottle = 0.4990
AP for bus = 0.8488
AP for car = 0.8577
AP for cat = 0.8737
AP for chair = 0.6147
AP for cow = 0.8233
AP for diningtable = 0.7917
AP for dog = 0.8559
AP for horse = 0.8709
AP for motorbike = 0.8474
AP for person = 0.7889
AP for pottedplant = 0.4996
AP for sheep = 0.7742
AP for sofa = 0.7913
AP for train = 0.8616
AP for tvmonitor = 0.7631
Mean AP = 0.7743

FPS

GTX 1060: ~45.45 FPS

Demos

Use a pre-trained SSD network for detection

Download a pre-trained network

SSD results on multiple datasets

Try the demo notebook

  • Make sure you have jupyter notebook installed.
  • Two alternatives for installing jupyter notebook:

    1. If you installed PyTorch with conda (recommended), then you should already have it. (Just navigate to the ssd.pytorch cloned repo and run): jupyter notebook

    2. If using pip:

# make sure pip is upgraded
pip3 install --upgrade pip
# install jupyter notebook
pip install jupyter
# Run this inside ssd.pytorch
jupyter notebook

Try the webcam demo

  • Works on CPU (may have to tweak cv2.waitkey for optimal fps) or on an NVIDIA GPU
  • This demo currently requires opencv2+ w/ python bindings and an onboard webcam
    • You can change the default webcam in demo/live.py
  • Install the imutils package to leverage multi-threading on CPU:
    • pip install imutils
  • Running python -m demo.live opens the webcam and begins detecting!

TODO

We have accumulated the following to-do list, which you can expect to be done in the very near future

  • Still to come:
    • Train SSD300 with batch norm
    • Add support for SSD512 training and testing
    • Add support for COCO dataset
    • Create a functional model definition for Sergey Zagoruyko's functional-zoo

References