Google Summer of Code 2019 Work Product Submission for the ELI5 Grad-CAM project under Scrapy, Python Software Foundation.
Hi! Welcome to the final report for the project titled “Grad-CAM Neural Network Explanations for ELI5” (https://summerofcode.withgoogle.com/projects/#5190417975345152).
All of my work was done as additions to the python library “ELI5” https://github.com/TeamHG-Memex/eli5.
I have worked on adding support to explain image and text classifier predictions in Keras and PyTorch. I have implemented the Grad-CAM technique (https://arxiv.org/abs/1610.02391) for explanations. This resulted in mypy annotated and commented Python source code (
eli5.formatters.image), pytest unit and integration tests, and sphinx docstrings, library descriptions and tutorials.
I have decided to exclude adding support for Tensorflow and non-classifier networks in this project.
Example of an explanation for why a network classified this image as “dog”
Example explanation for why a certain score was given by a sentiment analysis network
What is merged
Explaining Keras image classifiers
In this piece of work we explain the predictions done by a Keras classifier that takes images as its input.
Covered by two merged pull requests
See https://eli5.readthedocs.io/en/latest/libraries/keras.html and https://eli5.readthedocs.io/en/latest/tutorials/keras-image-classifiers.html for usage. The user can now call
eli5.explain_prediction() top level function on a Keras image classifier.
What is left to do
Explaining Keras text models
We explain the predictions of a Keras classifier that takes text as its input.
Covered by this open pull request: https://github.com/TeamHG-Memex/eli5/pull/325
- LAST COMMIT - https://github.com/TeamHG-Memex/eli5/pull/325/commits/7616a4e8048ad349cdac00eace80800ccb050db3, “Add gradcam test utils. Move tests from integration to unit in Keras”
Left to do
- Complete some TODO items in source comments.
- Reviewer feedback.
Explaining PyTorch image and text models
We explain classifiers defined in PyTorch that take either images or text as its input. This is a scaled down version of support we would have for Keras.
Covered by this open pull request: https://github.com/TeamHG-Memex/eli5/pull/327
- LAST COMMIT - https://github.com/TeamHG-Memex/eli5/pull/327/commits/9c8d7c6583d5142afbccbe1bbd68bd30b3477413, “Replace _forward_modules() with explicit named_modules() call (CI fix)”
Left to do
- Unit and integration tests.
- Text tutorial.
- PyTorch library description.
- Reviewer feedback.
What is working (based on manual testing)
- Reasonable explanations for image and text classifier predictions.
- Most of Keras features are supported (
counterfactual, and various text arguments).
Other (according to the original project plan)
These are optional. Either I can do them myself or let the users/maintainers do it.
Delivering a release
- Open a PR to help maintainers make a new ELI5 release (bump version, etc).
- Implement support for Keras models defined through Tensorflow (tf.keras).
- Support models for regression, Visual Question Answering, etc.
- Current code attempts to make this an easy thing to add support for.
- Regression can be converted into classification.
- Usual coding stuff - working with Keras, numpy, Pillow, PyTorch.
- Later down the line: making changes that “break” a lot of things, i.e. need to update other code, tests, docs.
- Prioritizing what to work on. Working up to speed to get "features" done.
- Estimating how long certain tasks will take.
- Finding hardware suitable for Machine Learning, i.e. using Kaggle kernels.
- Grad-CAM as a gradient method for explanations.
- Keras training and inference.
- PyTorch training and inference.
- Text and image preprocessing.
- Numpy, Pillow.
- Sphinx, reStructuredText.
- Mypy, pytest, tox, Travis CI, codecov.
- Git, virtualenv, pip.
- GitHub, Kaggle, Jupyter Notebook.