Unsupervised quantification of entity consistency between photos and text in real-world news

Das World Wide Web und die sozialen Medien übernehmen im heutigen Informationszeitalter eine wichtige Rolle für die Vermittlung von Nachrichten und Informationen. In der Regel werden verschiedene Modalitäten im Sinne der Informationskodierung wie beispielsweise Fotos und Text verwendet, um Nachrichten effektiver zu vermitteln oder Aufmerksamkeit zu erregen. Kommunikations- und Sprachwissenschaftler erforschen das komplexe Zusammenspiel zwischen Modalitäten seit Jahrzehnten und haben unter Anderem untersucht, wie durch die Kombination der Modalitäten zusätzliche Informationen oder eine neue Bedeutungsebene entstehen können. Die Anzahl gemeinsamer Konzepte oder Entitäten (beispielsweise Personen, Orte und Ereignisse) zwischen Fotos und Text stellen einen wichtigen Aspekt für die Bewertung der Gesamtaussage und Bedeutung eines multimodalen Artikels dar. Automatisierte Ansätze zur Quantifizierung von Bild-Text-Beziehungen können für zahlreiche Anwendungen eingesetzt werden. Sie ermöglichen beispielsweise eine effiziente Exploration von Nachrichten, erleichtern die semantische Suche von Multimedia-Inhalten in (Web)-Archiven oder unterstützen menschliche Analysten bei der Evaluierung der Glaubwürdigkeit von Nachrichten. Allerdings gibt es bislang nur wenige Ansätze, die sich mit der Quantifizierung von Beziehungen zwischen Fotos und Text beschäftigen. Diese Ansätze berücksichtigen jedoch nicht explizit die intermodalen Beziehungen von Entitäten, welche eine wichtige Rolle in Nachrichten darstellen, oder basieren auf überwachten multimodalen Deep-Learning-Techniken. Diese überwachten Lernverfahren können ausschließlich die intermodalen Beziehungen von Entitäten detektieren, die in annotierten Trainingsdaten enthalten sind. Um diese Forschungslücke zu schließen, wird in dieser Arbeit ein unüberwachter Ansatz zur Quantifizierung der intermodalen Konsistenz von Entitäten zwischen Fotos und Text in realen multimodalen Nachrichtenartikeln vorgestellt. Im ersten Teil dieser Arbeit werden neuartige Verfahren auf Basis von Deep Learning zur Extrahierung von Informationen aus Fotos vorgestellt, um Ereignisse (Events), Orte, Zeitangaben und Personen automatisch zu erkennen. Diese Verfahren bilden eine wichtige Voraussetzung, um die Beziehungen von Entitäten zwischen Bild und Text zu bewerten. Zunächst wird ein Ansatz zur Ereignisklassifizierung präsentiert, der neuartige Optimierungsfunktionen und Gewichtungsschemata nutzt um Ontologie-Informationen aus einer Wissensdatenbank in ein Deep-Learning-Verfahren zu integrieren. Das Training erfolgt anhand eines neu vorgestellten Datensatzes, der 570.540 Fotos und eine Ontologie mit 148 Ereignistypen enthält. Der Ansatz übertrifft die Ergebnisse von Referenzsystemen die keine strukturierten Ontologie-Informationen verwenden. Weiterhin wird ein DeepLearning-Ansatz zur Schätzung des Aufnahmeortes von Fotos vorgeschlagen, der Kontextinformationen über die Umgebung (Innen-, Stadt-, oder Naturaufnahme) und von Erdpartitionen unterschiedlicher Granularität verwendet. Die vorgeschlagene Lösung übertrifft die bisher besten Ergebnisse von aktuellen Forschungsarbeiten, obwohl diese deutlich mehr Fotos zum Training verwenden. Darüber hinaus stellen wir den ersten Datensatz zur Schätzung des Aufnahmejahres von Fotos vor, der mehr als eine Million Bilder aus den Jahren 1930 bis 1999 umfasst. Dieser Datensatz wird für das Training von zwei Deep-Learning-Ansätzen zur Schätzung des Aufnahmejahres verwendet, welche die Aufgabe als Klassifizierungs- und Regressionsproblem behandeln. Beide Ansätze erzielen sehr gute Ergebnisse und übertreffen Annotationen von menschlichen Probanden. Schließlich wird ein neuartiger Ansatz zur Identifizierung von Personen des öffentlichen Lebens und ihres gemeinsamen Auftretens in Nachrichtenfotos aus der digitalen Bibliothek Internet Archiv präsentiert. Der Ansatz ermöglicht es unstrukturierte Webdaten aus dem Internet Archiv mit Metadaten, beispielsweise zur semantischen Suche, zu erweitern. Experimentelle Ergebnisse haben die Effektivität des zugrundeliegenden Deep-Learning-Ansatzes zur Personenerkennung bestätigt. Im zweiten Teil dieser Arbeit wird ein unüberwachtes System zur Quantifizierung von BildText-Beziehungen in realen Nachrichten vorgestellt. Im Gegensatz zu bisherigen Verfahren liefert es automatisch neuartige Maße der intermodalen Konsistenz für verschiedene Entitätstypen (Personen, Orte und Ereignisse) sowie den Gesamtkontext. Das System ist nicht auf vordefinierte Datensätze angewiesen, und kann daher mit der Vielzahl und Diversität von Entitäten und Themen in Nachrichten umgehen. Zur Extrahierung von Entitäten aus dem Text werden geeignete Methoden der natürlichen Sprachverarbeitung eingesetzt. Examplarbilder für diese Entitäten werden automatisch aus dem Internet beschafft. Die vorgeschlagenen Methoden zur Informationsextraktion aus Fotos werden auf die Nachrichten- und heruntergeladenen Exemplarbilder angewendet, um die intermodale Konsistenz von Entitäten zu quantifizieren. Es werden zwei Aufgaben untersucht um die Qualität des vorgeschlagenen Ansatzes in realen Anwendungen zu bewerten. Experimentelle Ergebnisse für die Dokumentverifikation und die Beschaffung von Nachrichten mit geringer (potenzielle Fehlinformation) oder hoher multimodalen Konsistenz zeigen den Nutzen und das Potenzial des Ansatzes zur Unterstützung menschlicher Analysten bei der Untersuchung von Nachrichten.In today’s information age, the World Wide Web and social media are important sources for news and information. Different modalities (in the sense of information encoding) such as photos and text are typically used to communicate news more effectively or to attract attention. Communication scientists, linguists, and semioticians have studied the complex interplay between modalities for decades and investigated, e.g., how their combination can carry additional information or add a new level of meaning. The number of shared concepts or entities (e.g., persons, locations, and events) between photos and text is an important aspect to evaluate the overall message and meaning of an article. Computational models for the quantification of image-text relations can enable many applications. For example, they allow for more efficient exploration of news, facilitate semantic search and multimedia retrieval in large (web) archives, or assist human assessors in evaluating news for credibility. To date, only a few approaches have been suggested that quantify relations between photos and text. However, they either do not explicitly consider the cross-modal relations of entities – which are important in the news – or rely on supervised deep learning approaches that can only detect the cross-modal presence of entities covered in the labeled training data. To address this research gap, this thesis proposes an unsupervised approach that can quantify entity consistency between photos and text in multimodal real-world news articles. The first part of this thesis presents novel approaches based on deep learning for information extraction from photos to recognize events, locations, dates, and persons. These approaches are an important prerequisite to measure the cross-modal presence of entities in text and photos. First, an ontology-driven event classification approach that leverages new loss functions and weighting schemes is presented. It is trained on a novel dataset of 570,540 photos and an ontology with 148 event types. The proposed system outperforms approaches that do not use structured ontology information. Second, a novel deep learning approach for geolocation estimation is proposed that uses additional contextual information on the environmental setting (indoor, urban, natural) and from earth partitions of different granularity. The proposed solution outperforms state-of-the-art approaches, which are trained with significantly more photos. Third, we introduce the first large-scale dataset for date estimation with more than one million photos taken between 1930 and 1999, along with two deep learning approaches that treat date estimation as a classification and regression problem. Both approaches achieve very good results that are superior to human annotations. Finally, a novel approach is presented that identifies public persons and their co-occurrences in news photos extracted from the Internet Archive, which collects time-versioned snapshots of web pages that are rarely enriched with metadata relevant to multimedia retrieval. Experimental results confirm the effectiveness of the deep learning approach for person identification. The second part of this thesis introduces an unsupervised approach capable of quantifying image-text relations in real-world news. Unlike related work, the proposed solution automatically provides novel measures of cross-modal consistency for different entity types (persons, locations, and events) as well as the overall context. The approach does not rely on any predefined datasets to cope with the large amount and diversity of entities and topics covered in the news. State-of-the-art tools for natural language processing are applied to extract named entities from the text. Example photos for these entities are automatically crawled from the Web. The proposed methods for information extraction from photos are applied to both news images and example photos to quantify the cross-modal consistency of entities. Two tasks are introduced to assess the quality of the proposed approach in real-world applications. Experimental results for document verification and retrieval of news with either low (potential misinformation) or high cross-modal similarities demonstrate the feasibility of the approach and its potential to support human assessors to study news

Multimodal news analytics using measures of cross-modal entity and context consistency

The World Wide Web has become a popular source to gather information and news. Multimodal information, e.g., supplement text with photographs, is typically used to convey the news more effectively or to attract attention. The photographs can be decorative, depict additional details, but might also contain misleading information. The quantification of the cross-modal consistency of entity representations can assist human assessors’ evaluation of the overall multimodal message. In some cases such measures might give hints to detect fake news, which is an increasingly important topic in today’s society. In this paper, we present a multimodal approach to quantify the entity coherence between image and text in real-world news. Named entity linking is applied to extract persons, locations, and events from news texts. Several measures are suggested to calculate the cross-modal similarity of the entities in text and photograph by exploiting state-of-the-art computer vision approaches. In contrast to previous work, our system automatically acquires example data from the Web and is applicable to real-world news. Moreover, an approach that quantifies contextual image-text relations is introduced. The feasibility is demonstrated on two datasets that cover different languages, topics, and domains

Multimodal news analytics using measures of cross-modal entity and context consistency

The World Wide Web has become a popular source to gather information and news. Multimodal information, e.g., supplement text with photographs, is typically used to convey the news more effectively or to attract attention. The photographs can be decorative, depict additional details, but might also contain misleading information. The quantification of the cross-modal consistency of entity representations can assist human assessors’ evaluation of the overall multimodal message. In some cases such measures might give hints to detect fake news, which is an increasingly important topic in today’s society. In this paper, we present a multimodal approach to quantify the entity coherence between image and text in real-world news. Named entity linking is applied to extract persons, locations, and events from news texts. Several measures are suggested to calculate the cross-modal similarity of the entities in text and photograph by exploiting state-of-the-art computer vision approaches. In contrast to previous work, our system automatically acquires example data from the Web and is applicable to real-world news. Moreover, an approach that quantifies contextual image-text relations is introduced. The feasibility is demonstrated on two datasets that cover different languages, topics, and domains. © 2021, The Author(s)

Multimodal Geolocation Estimation of News Photos

The widespread growth of multimodal news requires sophisticated approaches to interpret content and relations of different modalities. Images are of utmost importance since they represent a visual gist of the whole news article. For example, it is essential to identify the locations of natural disasters for crisis management or to analyze political or social events across the world. In some cases, verifying the location(s) claimed in a news article might help human assessors or fact-checking efforts to detect misinformation, i.e., fake news. Existing methods for geolocation estimation typically consider only a single modality, e.g., images or text. However, news images can lack sufficient geographical cues to estimate their locations, and the text can refer to various possible locations. In this paper, we propose a novel multimodal approach to predict the geolocation of news photos. To enable this approach, we introduce a novel dataset called Multimodal Geolocation Estimation of News Photos (MMG-NewsPhoto). MMG-NewsPhoto is, so far, the largest dataset for the given task and contains more than half a million news texts with the corresponding image, out of which 3000 photos were manually labeled for the photo geolocation based on information from the image-text pairs. For a fair comparison, we optimize and assess state-of-the-art methods using the new benchmark dataset. Experimental results show the superiority of the multimodal models compared to the unimodal approaches

A Feature Analysis for Multimodal News Retrieval

Content-based information retrieval is based on the information contained in documents rather than using metadata such as keywords. Most information retrieval methods are either based on text or image. In this paper, we investigate the usefulness of multimodal features for cross-lingual news search in various domains: politics, health, environment, sport, and finance. To this end, we consider five feature types for image and text and compare the performance of the retrieval system using different combinations. Experimental results show that retrieval results can be improved when considering both visual and textual information. In addition, it is observed that among textual features entity overlap outperforms word embeddings, while geolocation embeddings achieve better performance among visual features in the retrieval task.Comment: CLEOPATRA Workshop co-located with ESWC 202

Multimodal Document Analytics for Banking Process Automation

In response to growing FinTech competition and the need for improved operational efficiency, this research focuses on understanding the potential of advanced document analytics, particularly using multimodal models, in banking processes. We perform a comprehensive analysis of the diverse banking document landscape, highlighting the opportunities for efficiency gains through automation and advanced analytics techniques in the customer business. Building on the rapidly evolving field of natural language processing (NLP), we illustrate the potential of models such as LayoutXLM, a cross-lingual, multimodal, pre-trained model, for analyzing diverse documents in the banking sector. This model performs a text token classification on German company register extracts with an overall F1 score performance of around 80\%. Our empirical evidence confirms the critical role of layout information in improving model performance and further underscores the benefits of integrating image information. Interestingly, our study shows that over 75% F1 score can be achieved with only 30% of the training data, demonstrating the efficiency of LayoutXLM. Through addressing state-of-the-art document analysis frameworks, our study aims to enhance process efficiency and demonstrate the real-world applicability and benefits of multimodal models within banking.Comment: A Preprin

Multimodal Automated Fact-Checking: A Survey

Misinformation is often conveyed in multiple modalities, e.g. a miscaptioned image. Multimodal misinformation is perceived as more credible by humans, and spreads faster than its text-only counterparts. While an increasing body of research investigates automated fact-checking (AFC), previous surveys mostly focus on text. In this survey, we conceptualise a framework for AFC including subtasks unique to multimodal misinformation. Furthermore, we discuss related terms used in different communities and map them to our framework. We focus on four modalities prevalent in real-world fact-checking: text, image, audio, and video. We survey benchmarks and models, and discuss limitations and promising directions for future researchComment: The 2023 Conference on Empirical Methods in Natural Language Processing (EMNLP): Finding