Background Activation Suppression for Weakly Supervised Object Localization and Semantic Segmentation

TL;DR

This paper introduces a Background Activation Suppression (BAS) method that leverages activation values rather than cross-entropy to improve weakly supervised object localization and semantic segmentation, achieving state-of-the-art results.

Contribution

The paper proposes a novel BAS approach that suppresses background activation and uses activation values for better object region learning, outperforming existing methods.

Findings

BAS significantly improves localization accuracy on benchmark datasets.

BAS achieves state-of-the-art weakly supervised semantic segmentation results.

Activation value-based learning outperforms cross-entropy in this context.

Abstract

Weakly supervised object localization and semantic segmentation aim to localize objects using only image-level labels. Recently, a new paradigm has emerged by generating a foreground prediction map (FPM) to achieve pixel-level localization. While existing FPM-based methods use cross-entropy to evaluate the foreground prediction map and to guide the learning of the generator, this paper presents two astonishing experimental observations on the object localization learning process: For a trained network, as the foreground mask expands, 1) the cross-entropy converges to zero when the foreground mask covers only part of the object region. 2) The activation value continuously increases until the foreground mask expands to the object boundary. Therefore, to achieve a more effective localization performance, we argue for the usage of activation value to learn more object regions. In this paper, we propose a Background Activation Suppression (BAS) method. Specifically, an Activation Map Constraint (AMC) module is designed to facilitate the learning of generator by suppressing the background activation value. Meanwhile, by using foreground region guidance and area constraint, BAS can learn the whole region of the object. In the inference phase, we consider the prediction maps of different categories together to obtain the final localization results. Extensive experiments show that BAS achieves significant and consistent improvement over the baseline methods on the CUB-200-2011 and ILSVRC datasets. In addition, our method also achieves state-of-the-art weakly supervised semantic segmentation performance on the PASCAL VOC 2012 and MS COCO 2014 datasets. Code and models are available at https://github.com/wpy1999/BAS-Extension.