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Bibliographic Details
Main Author: Tamura, Masato
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2504.00149
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author Tamura, Masato
author_facet Tamura, Masato
contents Precise action spotting has attracted considerable attention due to its promising applications. While existing methods achieve substantial performance by employing well-designed model architecture, they overlook a significant challenge: the temporal misalignment inherent in ground-truth labels. This misalignment arises when frames labeled as containing events do not align accurately with the actual event times, often as a result of human annotation errors or the inherent difficulties in precisely identifying event boundaries across neighboring frames. To tackle this issue, we propose a novel dynamic label assignment strategy that allows predictions to have temporal offsets from ground-truth action times during training, ensuring consistent event spotting. Our method extends the concept of minimum-cost matching, which is utilized in the spatial domain for object detection, to the temporal domain. By calculating matching costs based on predicted action class scores and temporal offsets, our method dynamically assigns labels to the most likely predictions, even when the predicted times of these predictions deviate from ground-truth times, alleviating the negative effects of temporal misalignment in labels. We conduct extensive experiments and demonstrate that our method achieves state-of-the-art performance, particularly in conditions where events are visually distinct and temporal misalignment in labels is common.
format Preprint
id arxiv_https___arxiv_org_abs_2504_00149
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publishDate 2025
record_format arxiv
spellingShingle Towards Precise Action Spotting: Addressing Temporal Misalignment in Labels with Dynamic Label Assignment
Tamura, Masato
Computer Vision and Pattern Recognition
Artificial Intelligence
Machine Learning
Precise action spotting has attracted considerable attention due to its promising applications. While existing methods achieve substantial performance by employing well-designed model architecture, they overlook a significant challenge: the temporal misalignment inherent in ground-truth labels. This misalignment arises when frames labeled as containing events do not align accurately with the actual event times, often as a result of human annotation errors or the inherent difficulties in precisely identifying event boundaries across neighboring frames. To tackle this issue, we propose a novel dynamic label assignment strategy that allows predictions to have temporal offsets from ground-truth action times during training, ensuring consistent event spotting. Our method extends the concept of minimum-cost matching, which is utilized in the spatial domain for object detection, to the temporal domain. By calculating matching costs based on predicted action class scores and temporal offsets, our method dynamically assigns labels to the most likely predictions, even when the predicted times of these predictions deviate from ground-truth times, alleviating the negative effects of temporal misalignment in labels. We conduct extensive experiments and demonstrate that our method achieves state-of-the-art performance, particularly in conditions where events are visually distinct and temporal misalignment in labels is common.
title Towards Precise Action Spotting: Addressing Temporal Misalignment in Labels with Dynamic Label Assignment
topic Computer Vision and Pattern Recognition
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2504.00149