An attention-based U-Net for detecting deforestation within satellite sensor imagery

John, David; Zhang, Ce

An attention-based U-Net for detecting deforestation within satellite sensor imagery

John, David; Zhang, Ce ORCID: https://orcid.org/0000-0001-5100-3584. 2022 An attention-based U-Net for detecting deforestation within satellite sensor imagery. International Journal of Applied Earth Observation and Geoinformation, 107, 102685. 9, pp. 10.1016/j.jag.2022.102685

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Official URL: http://dx.doi.org/10.1016/j.jag.2022.102685

Abstract/Summary

In this paper, we implement and analyse an Attention U-Net deep network for semantic segmentation using Sentinel-2 satellite sensor imagery, for the purpose of detecting deforestation within two forest biomes in South America, the Amazon Rainforest and the Atlantic Forest. The performance of Attention U-Net is compared with U-Net, Residual U-Net, ResNet50-SegNet and FCN32-VGG16 across three different datasets (three-band Amazon, four-band Amazon and Atlantic Forest). Results indicate that Attention U-Net provides the best deforestation masks when tested on each dataset, achieving average pixel-wise F1-scores of 0.9550, 0.9769 and 0.9461 for each dataset, respectively. Mask reproductions from each classifier were also analysed, showing that compared to the ground reference Attention U-Net could detect non-forest polygons more accurately than U-Net and overall it provides the most accurate segmentation of forest/deforest compared with benchmark approaches despite its reduced complexity and training time, thus being the first application of an Attention U-Net to an important deforestation segmentation task. This paper concludes with a brief discussion on the ability of the attention mechanism to offset the reduced complexity of Attention U-Net, as well as ideas for further research into optimising the architecture and applying attention mechanisms into other architectures for deforestation detection. Our code is available at https://github.com/davej23/attention-mechanism-unet.

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.jag.2022.102685

UKCEH and CEH Sections/Science Areas:

Soils and Land Use (Science Area 2017-24)

ISSN:

0303-2434

Additional Information:

Open Access paper - full text available via Official URL link.

Additional Keywords:

attention mechanism, attention U-Net, deep learning, deforestation mapping, Sentinel-2