Can Shuffling Video Benefit Temporal Bias Problem: A Novel Training Framework for Temporal Grounding

TL;DR

A novel framework using shuffled videos to address temporal bias, enhancing model generalization.

cs.CV 🔴 Advanced 2022-07-29 2 views
Jiachang Hao Haifeng Sun Pengfei Ren Jingyu Wang Qi Qi Jianxin Liao
temporal grounding video processing cross-modal matching temporal order discrimination deep learning

Key Findings

Methodology

This study proposes a novel training framework using shuffled videos to tackle the temporal bias problem. The framework introduces two auxiliary tasks: cross-modal matching and temporal order discrimination. The cross-modal matching task leverages content consistency between shuffled and original videos to force the model to mine visual content for semantic query matching. The temporal order discrimination task enhances understanding of long-term temporal contexts through differences in temporal order.

Key Results

  • On the Charades-STA dataset, the model achieved a 22.11% improvement in accuracy under IoU=0.5 conditions.
  • On the ActivityNet Captions dataset, the model demonstrated stronger generalization, especially under different temporal distributions.
  • Ablation studies confirmed the significant performance boost from auxiliary tasks.

Significance

This research breaks the temporal bias in training sets, enhancing model generalization. It holds significant academic value and offers new insights for practical applications in video understanding.

Technical Contribution

Technical contributions include a new training framework using shuffled videos to eliminate temporal bias, and the introduction of two auxiliary tasks that significantly enhance model generalization.

Novelty

This method is the first to use video shuffling to address temporal bias, with auxiliary tasks enhancing semantic matching capabilities, offering significant innovation over existing methods.

Limitations

  • The method may lead to loss of contextual information when handling long videos, affecting accuracy.
  • Shuffling videos may result in unrealistic training samples, impacting generalization.

Future Work

Future work could explore more complex video shuffling strategies and integrate other modalities to further enhance model performance.

AI Executive Summary

Temporal grounding aims to locate a target video moment that semantically corresponds to a given sentence query in an untrimmed video. Existing methods overly rely on temporal biases in training sets, limiting model generalization. This paper proposes a novel training framework using shuffled videos to address the temporal bias problem. The framework introduces cross-modal matching and temporal order discrimination tasks to promote model training. The cross-modal matching task leverages content consistency between shuffled and original videos to force the model to mine visual content for semantic query matching. The temporal order discrimination task enhances understanding of long-term temporal contexts through differences in temporal order. Experimental results show that this method significantly reduces reliance on temporal biases and strengthens generalization across different temporal distributions on the Charades-STA and ActivityNet Captions datasets. However, the method may lead to loss of contextual information when handling long videos. Future work could explore more complex video shuffling strategies to further enhance model performance.

Deep Analysis

Background

Temporal grounding has significant applications in video understanding, such as video captioning, video question answering, and video retrieval. However, existing methods face limitations in addressing temporal bias, leading to poor generalization across different temporal distributions.

Core Problem

The core problem is that existing methods overly rely on temporal biases in training sets, rather than reasoning target moment locations based on visual-textual semantic alignment.

Innovation

This paper proposes a novel training framework using shuffled videos to address temporal bias. It introduces two auxiliary tasks: cross-modal matching and temporal order discrimination, enhancing semantic matching capabilities and understanding of long-term temporal contexts.

Methodology

  • �� Construct input using shuffled videos to generate pseudo videos.
  • �� Design cross-modal matching task to predict frame-level cross-modal relevance.
  • �� Design temporal order discrimination task to determine if video moment sequence is in correct order.

Experiments

Experiments were conducted on Charades-STA and ActivityNet Captions datasets using I3D features as visual input. Evaluation metrics include R@n, IoU=θ, and mIoU.

Results

On the Charades-STA dataset, the model achieved a 22.11% improvement in accuracy under IoU=0.5 conditions. On the ActivityNet Captions dataset, the model demonstrated stronger generalization.

Applications

This method can be applied in video captioning, video question answering, and video retrieval, especially in scenarios requiring handling of different temporal distributions.

Limitations & Outlook

Despite its effectiveness in addressing temporal bias, the method may lead to loss of contextual information when handling long videos, affecting accuracy.

Plain Language Accessible to non-experts

Imagine watching a movie with many scenes. Our task is to find a specific scene, like when the protagonist wakes up. Normally, we might guess its location based on the movie's sequence, but this could lead to errors. To avoid this, we shuffle the movie's scenes and then find the specific scene. It's like shuffling a puzzle and then putting it back together. This way, we better understand each piece's content rather than just relying on the sequence.

ELI14 Explained like you're 14

Imagine playing a puzzle game. Usually, you'd use the picture on the box to solve it, but if the picture is shuffled, you'd have to look at each puzzle piece's details to solve it, right? This paper does just that! They shuffle video clips and then let the computer find specific scenes. This way, the computer can't just rely on the sequence but has to truly understand each clip's content. Isn't that cool?

Glossary

Temporal Grounding

Locating a target video moment that semantically corresponds to a given sentence query in an untrimmed video.

Used in tasks like video captioning and video question answering.

Temporal Bias

The model overly relies on temporal biases in training sets rather than reasoning target moment locations based on visual-textual semantic alignment.

Affects model generalization across different temporal distributions.

Cross-Modal Matching

Leveraging content consistency between shuffled and original videos to force the model to mine visual content for semantic query matching.

An auxiliary task to enhance semantic matching capabilities.

Temporal Order Discrimination

Enhancing understanding of long-term temporal contexts through differences in temporal order.

An auxiliary task to enhance understanding of long-term temporal contexts.

Pseudo Videos

Training samples generated by shuffling video clips to eliminate temporal bias.

Used to train models to enhance generalization.

Open Questions Unanswered questions from this research

  • 1 How to shuffle long videos without losing contextual information?
  • 2 Can integrating other modalities further enhance model performance?

Applications

Immediate Applications

Video Captioning

Enhancing semantic matching capabilities to improve the accuracy and robustness of caption generation.

Long-term Vision

Video Understanding

Enhancing generalization across different scenarios by addressing temporal bias.

Abstract

Temporal grounding aims to locate a target video moment that semantically corresponds to the given sentence query in an untrimmed video. However, recent works find that existing methods suffer a severe temporal bias problem. These methods do not reason the target moment locations based on the visual-textual semantic alignment but over-rely on the temporal biases of queries in training sets. To this end, this paper proposes a novel training framework for grounding models to use shuffled videos to address temporal bias problem without losing grounding accuracy. Our framework introduces two auxiliary tasks, cross-modal matching and temporal order discrimination, to promote the grounding model training. The cross-modal matching task leverages the content consistency between shuffled and original videos to force the grounding model to mine visual contents to semantically match queries. The temporal order discrimination task leverages the difference in temporal order to strengthen the understanding of long-term temporal contexts. Extensive experiments on Charades-STA and ActivityNet Captions demonstrate the effectiveness of our method for mitigating the reliance on temporal biases and strengthening the model's generalization ability against the different temporal distributions. Code is available at https://github.com/haojc/ShufflingVideosForTSG.

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