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Migration-related video retrieval

Presentation of the paper titled "Migration-Related Semantic Concepts for the Retrieval of Relevant Video Content", by E. Elejalde, D. Galanopoulos, C. Niederee, V. Mezaris, published in the proceedings of the Int. Workshop on Artificial Intelligence and Robotics for Law Enforcement Agencies (AIRLEAs) at the 3rd Int. Conf. on Intelligent Technologies and Applications (INTAP 2020), Gjovik, Norway, Sept. 2020.

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Migration-related video retrieval

  1. 1. The MIRROR project has received funding from the European Union’s Horizon 2020 research and innovation action program under grant agreement № 832921. Migration-Related Semantic Concepts for the Retrieval of Relevant Video Content Erick Elejalde, Damianos Galanopoulos, Claudia Niederee, Vasileios Mezaris Int. Workshop on Artificial Intelligence and Robotics for Law Enforcement Agencies (AIRLEAs) @ 3rd Int. Conf. on Intelligent Technologies and Applications (INTAP 2020), Gjovik, Norway, Sept. 2020.
  2. 2. 2 Introduction Problem ● Migration is a complex process and a critical issue ● A plethora of factors lead to migration decisions ● Social media may be used to manipulate perception and lead to misperceptions Solutions ● A better understanding of these decisions is critical ● Automatic analysis of migration related media items ● A novel approach to bridge the gap between the migration driven factors and their expressions in a video
  3. 3. 3 Approach Top-down and bottom-up approach combination ● Top-down approach ○ Theoretical understanding of migration factors and decisions ○ Domain conceptualization ○ A set of Migration-Related Semantic Concepts (MRSCs) is defined ● Bottom-up approach ○ Visual content interpretation and analysis ○ Video analysis for retrieving related video or images ○ How are MRSCs expressed in videos and images?
  4. 4. 4 Migration-Related Semantic Concepts (MRSCs) What are MRSCs? ● Semantic concepts relevant in the context of migration How are MRSCs defined? ● In-depth study of migration theories ● Discussions with domain experts ● Semantic concepts collection expresses the migration aspects ● Based on three popular theoretical approaches ○ Νeo-classical economic equilibrium ○ Historical-structural approach ○ Migration systems theory
  5. 5. 5 MRSC - Migration Theories Νeo-classical economic equilibrium ● Focuses on imbalance conditions between origin country and destination ● People try to maximize their benefits take into consideration any constraints ● Criticism: ignores the historical antecedents of movements and ignoring the role of the state
  6. 6. 6 MRSC - Migration Theories Historical-structural approach ● Based on the Marxist view of political economy ● Stresses the unequal distribution of the economy ● Global scaled recruitment of cheap labor from the capital ● Uneven economy development maintenance ● Criticism: no attention to personal motivations
  7. 7. 7 MRSC - Migration Theories Migration systems theory ● Response to other theories criticism ● More holistic analysis of the migration factors ● The migration process is the result of interacting macro-, meso- and microstructures
  8. 8. 8 MRSC - Factors Classification ● Semantic concepts are combined to form meaningful templates ○ For example, “family” and “war” combined as “Families in war” ● Based on such patterns, a hierarchical structure is constructed ● 106 MRSCs are grouped into five categories ○ Economic ○ Social ○ Demographic ○ Environmental ○ Political ● 20 on the first level and 86 under them
  9. 9. 9 MRSC - Factor Classification 106 MRSCs organized on five categories and two levels
  10. 10. 10 MRSC-based Video Retrieval ● Ad-Hoc Video Search (AVS) is a similar cross-modal retrieval problem ● Based on a state-of-the-art method for the AVS problem ● Video shots and free text encoding into a joint feature space ● Retrieve the most relevant video shots by inputting an MRSC ● Attention-based dual encoding network ● Trained with video-caption pairs ● MRSCs augmentation with a small set of complex sentences
  11. 11. 11 MRSC-based Video Retrieval Method overview
  12. 12. 12 MRSC-based Video Retrieval Attention-based dual encoding network adjustment
  13. 13. 13 Experiments and Results Experimental set-up ● Training datasets ○ TGIF & MSR-VTT ● Keyframe representation ○ ResNet 152 trained on Imagenet 11K ● Word embeddings ○ Word2Vec ○ BERT ● Evaluation datasets ○ TRECVID SIN 2013 & 2015 ● Evaluation metric ○ Mean extended inferred average precision (MXinfAP)
  14. 14. 14 Experiments and Results Why TRECVID SIN as an evaluation dataset? ● Excessively specific problem ● No domain-specific video retrieval datasets are available ● SIN task is very similar to ours ● Abstract concepts to be correlated with video shots ● Well known state-of-the-art methods to be compared
  15. 15. 15 Experiments and Results
  16. 16. 16 Experiments and Results SIN concept augmentation improvements ● “Telephones” is described as “speaking on a telephone” and “talking on a telephone” ○ SIN’13: XinfAP improved from 0.0 to 0.3151 ○ SIN’15: XinfAP improved from 0.0 to 0.308 ● “Bicycling” is described as “a man riding a bike”, “people riding bicycles” and “a woman on a bike” ○ SIN’15: XinfAP improved from 0.0569 to 0.3730
  17. 17. 17 Experiments and Results ● Conventional concept retrieval methods are used as the baseline ● Baselines use predefined sets of visual concepts and positive exemplars for every concept ● Competitive results even with the absence of training exemplars
  18. 18. 18 Experiments and Results ● Visual examples
  19. 19. 19 Conclusion and Future work ● A novel approach for understanding migration and migration decisions ● Theoretically defined MRSCs provides ○ A better view of the migration topic ○ A common language for analysis ● Video analysis to bridge the gap between MRSCs and video Future work ● Fully automatic pipeline for automatic MRSCs augmentation ● Better encoding and improved visual and text representations ● Domain-specific dataset
  20. 20. 20 Contact details Dr. Vasileios Mezaris Information Technologies Institute-CERTH bmezaris@iti.gr www.iti.gr/~bmezaris