Increasing Shape Bias in ImageNet-Trained Networks Using Transfer Learning and Domain-Adversarial Methods

TL;DR

This paper enhances shape bias in CNNs trained on ImageNet by combining style-transfer and domain-adversarial training, leading to more robust models that focus on shape rather than texture or color.

Contribution

It introduces a novel approach that extends style-transfer methods with domain-adversarial training to increase shape bias in CNNs.

Findings

Increased robustness of CNNs to texture and style variations.

No significant improvement in classification accuracy.

Enhanced shape bias in learned representations.

Abstract

Convolutional Neural Networks (CNNs) have become the state-of-the-art method to learn from image data. However, recent research shows that they may include a texture and colour bias in their representation, contrary to the intuition that they learn the shapes of the image content and to human biological learning. Thus, recent works have attempted to increase the shape bias in CNNs in order to train more robust and accurate networks on tasks. One such approach uses style-transfer in order to remove texture clues from the data. This work reproduces this methodology on four image classification datasets, as well as extends the method to use domain-adversarial training in order to further increase the shape bias in the learned representation. The results show the proposed method increases the robustness and shape bias of the CNNs, while it does not provide a gain in accuracy.