AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network

Micro-expressions are the small, brief facial expression changes that humans momentarily show during emotional experiences, and their data annotation is complicated, which leads to the scarcity of micro-expression data. To extract salient and distinguishing features from a limited dataset, we propos...

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Main Authors: Chenghao Fu, Wenzhong Yang, Danny Chen, Fuyuan Wei
Format: Article
Language:English
Published: MDPI AG 2023-07-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/25/7/1064
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author Chenghao Fu
Wenzhong Yang
Danny Chen
Fuyuan Wei
author_facet Chenghao Fu
Wenzhong Yang
Danny Chen
Fuyuan Wei
author_sort Chenghao Fu
collection DOAJ
description Micro-expressions are the small, brief facial expression changes that humans momentarily show during emotional experiences, and their data annotation is complicated, which leads to the scarcity of micro-expression data. To extract salient and distinguishing features from a limited dataset, we propose an attention-based multi-scale, multi-modal, multi-branch flow network to thoroughly learn the motion information of micro-expressions by exploiting the attention mechanism and the complementary properties between different optical flow information. First, we extract optical flow information (horizontal optical flow, vertical optical flow, and optical strain) based on the onset and apex frames of micro-expression videos, and each branch learns one kind of optical flow information separately. Second, we propose a multi-scale fusion module to extract more prosperous and more stable feature expressions using spatial attention to focus on locally important information at each scale. Then, we design a multi-optical flow feature reweighting module to adaptively select features for each optical flow separately by channel attention. Finally, to better integrate the information of the three branches and to alleviate the problem of uneven distribution of micro-expression samples, we introduce a logarithmically adjusted prior knowledge weighting loss. This loss function weights the prediction scores of samples from different categories to mitigate the negative impact of category imbalance during the classification process. The effectiveness of the proposed model is demonstrated through extensive experiments and feature visualization on three benchmark datasets (CASMEII, SAMM, and SMIC), and its performance is comparable to that of state-of-the-art methods.
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spelling doaj.art-46ffb9b6940a45409994dfda837ffe972023-11-18T19:14:15ZengMDPI AGEntropy1099-43002023-07-01257106410.3390/e25071064AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow NetworkChenghao Fu0Wenzhong Yang1Danny Chen2Fuyuan Wei3School of Information Science and Engineering, Xinjiang University, Urumqi 830017, ChinaSchool of Information Science and Engineering, Xinjiang University, Urumqi 830017, ChinaSchool of Information Science and Engineering, Xinjiang University, Urumqi 830017, ChinaSchool of Information Science and Engineering, Xinjiang University, Urumqi 830017, ChinaMicro-expressions are the small, brief facial expression changes that humans momentarily show during emotional experiences, and their data annotation is complicated, which leads to the scarcity of micro-expression data. To extract salient and distinguishing features from a limited dataset, we propose an attention-based multi-scale, multi-modal, multi-branch flow network to thoroughly learn the motion information of micro-expressions by exploiting the attention mechanism and the complementary properties between different optical flow information. First, we extract optical flow information (horizontal optical flow, vertical optical flow, and optical strain) based on the onset and apex frames of micro-expression videos, and each branch learns one kind of optical flow information separately. Second, we propose a multi-scale fusion module to extract more prosperous and more stable feature expressions using spatial attention to focus on locally important information at each scale. Then, we design a multi-optical flow feature reweighting module to adaptively select features for each optical flow separately by channel attention. Finally, to better integrate the information of the three branches and to alleviate the problem of uneven distribution of micro-expression samples, we introduce a logarithmically adjusted prior knowledge weighting loss. This loss function weights the prediction scores of samples from different categories to mitigate the negative impact of category imbalance during the classification process. The effectiveness of the proposed model is demonstrated through extensive experiments and feature visualization on three benchmark datasets (CASMEII, SAMM, and SMIC), and its performance is comparable to that of state-of-the-art methods.https://www.mdpi.com/1099-4300/25/7/1064micro-expression recognitionattention mechanismslogit-adjusted loss
spellingShingle Chenghao Fu
Wenzhong Yang
Danny Chen
Fuyuan Wei
AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network
Entropy
micro-expression recognition
attention mechanisms
logit-adjusted loss
title AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network
title_full AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network
title_fullStr AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network
title_full_unstemmed AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network
title_short AM3F-FlowNet: Attention-Based Multi-Scale Multi-Branch Flow Network
title_sort am3f flownet attention based multi scale multi branch flow network
topic micro-expression recognition
attention mechanisms
logit-adjusted loss
url https://www.mdpi.com/1099-4300/25/7/1064
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AT wenzhongyang am3fflownetattentionbasedmultiscalemultibranchflownetwork
AT dannychen am3fflownetattentionbasedmultiscalemultibranchflownetwork
AT fuyuanwei am3fflownetattentionbasedmultiscalemultibranchflownetwork