project-surfrider

Instructions and code for the course project - based on ONG Surfrider detection of plastics in rivers.

Surfrider - Plastic Monitoring on Rivers

This course project makes use of an ongoing open source project led by Surfrider Europe, which aims at quantifying plastic pollution in rivers through space and time. Plastic Waste in oceans mostly comes from rivers (80%), and it is very difficult to assess precisely where they come from. This will be used to monitor river banks to take local decisions, measure effectiveness of policies at local and global scales, and has thus a very concrete importance.

In practice, video streams are captured on river banks from kayaks (with their geolocalisation), and then fed to a model which aims at quantifying the number and types of objects. In the first version, there are three types (classes) of plastic litter:

• Plastic Bottles:
• Plastic Fragments:
• Other types of waste

Your goal is to build a short project around plastic detection using modern Deep Learning algorithms.

Organization / format

• Groups of 2 people
• The output is a 5 minutes recording of you describing what you did over slides or a notebook. No need to record your face. Voice over some slides and/or a full screen scrolling notebook is enough. Use any screencast software to do the recording.
• Note that:
  • You should rehearse the recording so that it is easy to understands and fits strictly within the 5 minutes (fair comparison implies we will stop the video player at the 5 min mark).
  • Don't waste your time re-explaining the context of the project, but rather what you decided to build, why it is relevant, what you achieved, what are the limitations of your solution and what you would do in future work.
  • Try to be original: don't stick with the simplest, don't hesitate to test alternative architectures and be audacious! This is the best way to learn.
• The project will account for 1/3 of the final grade. Grading will take into account: originality, technical quality, model performance, oral explanations

Baseline

You can download a training dataset on this link.

You can download videos of rivers here: Google Drive Link. They are provided and owned by Surfrider.

The actual ongoing project is open source. If needed, you may look at the training notebook provided in the repository, with an example runnable on Colab.

What to do

Your goal is to build a plastic detection model as useful as possible. To do so, you may optimize the following:

• Have the best performance in terms of average precision of detected objects.
• Have the least amount of false positives when running on rivers that do not include garbage. You may for instance test using extracted frames from the videos and build a metric which counts the number of false positives.

Pick up one idea from the list below:

• Improving the data:
  • by using smart data augmentation schemes;
  • unlabeled data (from provided videos for instance), or newly labeled data;
  • external data (for instance TACO).
• Improving the model:
  • A more recent Object detection architecture is the most straightforward way to improve performances, see references below. You may reuse existing code and improve on it. Be warned, object detection models are rather hard to implement from scratch.
  • From Object detection to Segmentation (will probably require additional labels: masks, which are found in TACO for instance).
• Your own idea!

Feel free to use the software stack of your choice (Tensorflow/Keras, Pytorch....). Be careful, most of the open source detection models in tensorflow are in Tensorflow < 2.0.

Advanced possibilities

If you want to go further:

• Build a tracking system on sequential video frames: align detections from one frame to the next to avoid counting the same object twice in a sequence of consecutive frames. You may then count the different detected plastics (this is the end goal of the project!)
• Try and compress the network to deploy it on mobile phone and make it analyze the video recorded from its camera in real time (you may consider TensorflowLite).

Model References

Single Stage Detectors

• YoloV3 with associated Tensorflow code: https://github.com/zzh8829/yolov3-tf2
• RetinaNet https://github.com/fizyr/keras-retinanet

Two Stage Detectors

• FasterRCNN Tensorflow Object Detection or TensorPack
• Any Faster-RCNN refinement, available for instance in Detectron (in Pytorch)
• Feel free to explore other methods and papers, be creative!

Other types of detection

As the goal is to count plastic waste, you may only want to detect the center of the object, corners or keypoints rather than the bounding box. It is possible to convert the dataset and try one of these approach:

• CenterNet Paper Github
• CornerNet Paper Github

Tracking

As we will process the videos to get a few frames every second, the output of the detector on each frame will often detect the same plastic object. Using tracking it is possible to follow multiple objects and be able to count them.

• A review on multiple object tracking
• Kalman Filters, Particle Filters
• DeepSort: Blog review Github

Getting Involved

If you're interested to get involved more in the actual project, please contact Charles Ollion.