Few-shot action recognition with permutation-invariant attention
Many few-shot learning models focus on recognising images. In contrast, we tackle a challenging task of few-shot action recognition from videos. We build on a C3D encoder for spatio-temporal video blocks to capture short-range action patterns. Such encoded blocks are aggregated by permutation-invari...
Main Authors: | , , , , , |
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Format: | Conference item |
Language: | English |
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Springer
2020
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_version_ | 1797053795188867072 |
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author | Zhang, H Zhang, L Qi, X Li, H Torr, PHS Koniusz, P |
author_facet | Zhang, H Zhang, L Qi, X Li, H Torr, PHS Koniusz, P |
author_sort | Zhang, H |
collection | OXFORD |
description | Many few-shot learning models focus on recognising images. In contrast, we tackle a challenging task of few-shot action recognition from videos. We build on a C3D encoder for spatio-temporal video blocks to capture short-range action patterns. Such encoded blocks are aggregated by permutation-invariant pooling to make our approach robust to varying action lengths and long-range temporal dependencies whose patterns are unlikely to repeat even in clips of the same class. Subsequently, the pooled representations are combined into simple relation descriptors which encode so-called query and support clips. Finally, relation descriptors are fed to the comparator with the goal of similarity learning between query and support clips. Importantly, to re-weight block contributions during pooling, we exploit spatial and temporal attention modules and self-supervision. In naturalistic clips (of the same class) there exists a temporal distribution shift–the locations of discriminative temporal action hotspots vary. Thus, we permute blocks of a clip and align the resulting attention regions with similarly permuted attention regions of non-permuted clip to train the attention mechanism invariant to block (and thus long-term hotspot) permutations. Our method outperforms the state of the art on the HMDB51, UCF101, miniMIT datasets. |
first_indexed | 2024-03-06T18:48:34Z |
format | Conference item |
id | oxford-uuid:0f61cb08-de97-42f7-aff6-3632500644a6 |
institution | University of Oxford |
language | English |
last_indexed | 2024-03-06T18:48:34Z |
publishDate | 2020 |
publisher | Springer |
record_format | dspace |
spelling | oxford-uuid:0f61cb08-de97-42f7-aff6-3632500644a62022-03-26T09:50:58ZFew-shot action recognition with permutation-invariant attentionConference itemhttp://purl.org/coar/resource_type/c_5794uuid:0f61cb08-de97-42f7-aff6-3632500644a6EnglishSymplectic ElementsSpringer2020Zhang, HZhang, LQi, XLi, HTorr, PHSKoniusz, PMany few-shot learning models focus on recognising images. In contrast, we tackle a challenging task of few-shot action recognition from videos. We build on a C3D encoder for spatio-temporal video blocks to capture short-range action patterns. Such encoded blocks are aggregated by permutation-invariant pooling to make our approach robust to varying action lengths and long-range temporal dependencies whose patterns are unlikely to repeat even in clips of the same class. Subsequently, the pooled representations are combined into simple relation descriptors which encode so-called query and support clips. Finally, relation descriptors are fed to the comparator with the goal of similarity learning between query and support clips. Importantly, to re-weight block contributions during pooling, we exploit spatial and temporal attention modules and self-supervision. In naturalistic clips (of the same class) there exists a temporal distribution shift–the locations of discriminative temporal action hotspots vary. Thus, we permute blocks of a clip and align the resulting attention regions with similarly permuted attention regions of non-permuted clip to train the attention mechanism invariant to block (and thus long-term hotspot) permutations. Our method outperforms the state of the art on the HMDB51, UCF101, miniMIT datasets. |
spellingShingle | Zhang, H Zhang, L Qi, X Li, H Torr, PHS Koniusz, P Few-shot action recognition with permutation-invariant attention |
title | Few-shot action recognition with permutation-invariant attention |
title_full | Few-shot action recognition with permutation-invariant attention |
title_fullStr | Few-shot action recognition with permutation-invariant attention |
title_full_unstemmed | Few-shot action recognition with permutation-invariant attention |
title_short | Few-shot action recognition with permutation-invariant attention |
title_sort | few shot action recognition with permutation invariant attention |
work_keys_str_mv | AT zhangh fewshotactionrecognitionwithpermutationinvariantattention AT zhangl fewshotactionrecognitionwithpermutationinvariantattention AT qix fewshotactionrecognitionwithpermutationinvariantattention AT lih fewshotactionrecognitionwithpermutationinvariantattention AT torrphs fewshotactionrecognitionwithpermutationinvariantattention AT koniuszp fewshotactionrecognitionwithpermutationinvariantattention |