Waste Classifier Machine Learning

Machine Learning App Development

Machine Learning-backed ‘Waste Classifier App’ to Help Correctly Deposit Waste

Our Partner

Rootstrap partnered with Abito, an Uruguayan company that works with schools and businesses to help them recycle. Abito promotes the revaluation of waste by facilitating the classification at the source and the transport of waste so that it can be recycled and composted.

Abito has an effective classification system that breaks trash into the following categories:

  1. Compostable items
  2. Plastic
  3. Paper & Cardboard
  4. Recyclable items
  5. General Trash

To help Rootstrap begin training the model they provided the Montevideo office with the necessary trash bins for classifying garbage correctly.



Develop an innovative Waste Classifier app powered by Machine Learning algorithms to educate users on the correct and most effective method to dispose of waste and recycle items efficiently.


From a picture of the items/garbage, the application will be able to tell you where to correctly classify and dispose of the items in question.


Provide a functionality via Machine Learning where users can contribute to the model’s performance to produce the most accurate decisions possible and train the model to reduce as many human elements as possible.


Promote awareness of the waste classification process and its benefits for the environment. Start a conversation around the topic and encourage user feedback and participation to improve the model.


Creating and building an effective machine learning model to classify garbage correctly is no easy task. It can be difficult to correctly know where to put waste, and transitioning these human difficulties into a machine learning environment was the biggest challenge Rootstrap’s Engineers faced.

The project originally started out as a PIS (software engineering project where students simulate a real company), and during the process, the model had to be completely rebuilt from scratch as the standards required for PIS were not high enough for real-life requirements. The model needed a full revamp to improve performance and machine learning algorithms.

A machine learning model of this type needs a significantly large amount of data to learn in general, and in this case,  classifying specific types of garbage correctly, needs thousands of pictures of garbage to be incorporated into the cloud for the model to learn.

The general confusion surrounding what can and cannot be recycled and classification mistakes can have consequences. Rootstrap’s Engineers had and continue to put vast amounts of effort and work into determining the correct methods of recycling to train the model.

Examples of recycling issues & requirements:

  • Keeping all recyclable items clean.
  • Paper and cardboard cannot be wrinkled.
  • Time-consuming determining what can and cannot be recycled.
  • Specific items such as yogurt containers & plastic bags cannot be recycled.
  • Specific items such as plastic bottles contain logos that cannot be recycled.
  • If the paper contains any plastic it can’t be recycled such as magazine paper.
  • Plastic items must have a code that is either 1, 2, or 4. Otherwise, they can’t be recycled


As mentioned, the ‘RootTrash’ mobile application project began as a PIS project where Rootstrap worked with local students from Universidad de la República – Uruguayan public university, in which they mentored the project. Rootstrap  Engineers presented them with the project to create this application. Once the PIS was completed, Rootstrap’s Machine Learning Engineers refactored the code to create an internal project. They incorporated the machine learning model into the Rootstrap Montevideo office.

They designed, developed, and trained this machine learning model to classify garbage correctly while constantly improving its performance via user feedback. To achieve this, they developed and deployed a Django server, as well as a React Native FrontEnd to ensure the application can work on iOS and Android.

Roostrap’s Engineers set up the correct recycling bins with test devices with the app installed near trash cans to take pictures to train the model. These large amounts of pictures are stored in the cloud. They then deployed the working model to the cloud, constantly improving through maintenance and user feedback.

RootTrash Mobile Application Screenshot

How it works

  • Mobile App is separate from the model
  • The app uses pictures to retrain and maintain the model
  • Option in the app to correct the model (so it can get better and retrain)
  • The model promotes user participation via a specific feature used to gain feedback and improve overall performance
  • App Takes pictures of items sent to model in the cloud and returns correct classification to the app
  • The application then asks users if is this correct therefore encouraging feedback
  • Example – Is this correct / do you think the model did a correct classification? Yes/no/unsure


An innovative, fully functional, and constantly improving Waste Classifier mobile application that can successfully classify solutions and results.

This highly successful product is currently deployed internally and in the development phase for full release on iOS and Android. This machine learning model is effectively developed in a generic manner to ensure it is flexible and not solely dependent on Abito’s classification (project partner) or any single company or entity.

This flexibility allows for users of the model to edit to their specific needs and allows for integrations with other criteria for classification, such as classifying other categories like metal over plastic. By deploying the working model to the cloud, the model is constantly improving through maintenance and user feedback via an embedded option in the app to correct results/classifications to retrain and better the machine learning model.

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