The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
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Journalistic Image Access: Description, Categorization and Searching

Stina Westman

Doctoral dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the School of Science for public examination and debate in Auditorium AS1 at the Aalto University School of Science (Espoo, Finland) on the 21st of October 2011 at 12 noon.

Overview in PDF format (ISBN 978-952-60-4293-0)   [2434 KB]
Dissertation is also available in print (ISBN 978-952-60-4292-3)

Abstract

The quantity of digital imagery continues to grow, creating a pressing need to develop efficient methods for organizing and retrieving images. Knowledge on user behavior in image description and search is required for creating effective and satisfying searching experiences. The nature of visual information and journalistic images creates challenges in representing and matching images with user needs.

The goal of this dissertation was to understand the processes in journalistic image access (description, categorization, and searching), and the effects of contextual factors on preferred access points. These were studied using multiple data collection and analysis methods across several studies. Image attributes used to describe journalistic imagery were analyzed based on description tasks and compared to a typology developed through a meta-analysis of literature on image attributes. Journalistic image search processes and query types were analyzed through a field study and multimodal image retrieval experiment. Image categorization was studied via sorting experiments leading to a categorization model. Advances to research methods concerning search tasks and categorization procedures were implemented.

Contextual effects on image access were found related to organizational contexts, work, and search tasks, as well as publication context. Image retrieval in a journalistic work context was contextual at the level of image needs and search process. While text queries, together with browsing, remained the key access mode to journalistic imagery, participants also used visual access modes in the experiment, constructing multimodal queries. Assigned search task type and searcher expertise had an effect on query modes utilized. Journalistic images were mostly described and queried for on the semantic level but also syntactic attributes were used. Constraining the description led to more abstract descriptions. Image similarity was evaluated mainly based on generic semantics. However, functionally oriented categories were also constructed, especially by domain experts. Availability of page context promoted thematic rather than object-based categorization.

The findings increase our understanding of user behavior in image description, categorization, and searching, as well as have implications for future solutions in journalistic image access. The contexts of image production, use, and search merit more interest in research as these could be leveraged for supporting annotation and retrieval. Multiple access points should be created for journalistic images based on image content and function. Support for multimodal query formulation should also be offered. The contributions of this dissertation may be used to create evaluation criteria for journalistic image access systems.

This thesis consists of an overview and of the following 6 publications:

  1. Mari Laine-Hernandez and Stina Westman. 2006. Image semantics in the description and categorization of journalistic photographs. Proceedings of the American Society for Information Science and Technology, volume 43, number 1, pages 1-25.
  2. Stina Westman. 2009. Image users' needs and searching behaviour. In: Ayşe Göker and John Davies (editors). Information Retrieval: Searching in the 21st Century. Chichester, United Kingdom: John Wiley & Sons. Chapter 4, pages 63-84. ISBN 978-0-470-02762-2.
  3. Stina Westman and Pirkko Oittinen. 2006. Image retrieval by end-users and intermediaries in a journalistic work context. In: Ian Ruthven (editor). Proceedings of the First International Conference on Information Interaction in Context (IIiX 2006). Copenhagen, Denmark. 18-20 October 2006. New York, NY, USA. ACM. Pages 102-110. ISBN 1-59593-482-0.
  4. Stina Westman, Antti Lustila, and Pirkko Oittinen. 2008. Search strategies in multimodal image retrieval. In: Pia Borlund, Jesper W. Schneider, Mounia Lalmas, Anastasios Tombros, John Feather, Diane Kelly, and Arjen P. de Vries (editors). Proceedings of the Second International Symposium on Information Interaction in Context (IIiX 2008). London, United Kingdom. 14-17 October 2008. New York, NY, USA. ACM. ACM International Conference Proceeding Series, volume 348, pages 13-20. ISBN 978-1-60558-310-5.
  5. Stina Westman and Mari Laine-Hernandez. 2008. The effect of page context on magazine image categorization. Proceedings of the American Society for Information Science and Technology, volume 45, number 1, pages 1-11.
  6. Stina Westman, Mari Laine-Hernandez, and Pirkko Oittinen. 2011. Development and evaluation of a multifaceted magazine image categorization model. Journal of the American Society for Information Science and Technology, volume 62, number 2, pages 295-313.

Errata of publications 2, 3, 5 and 6

Keywords: image journalism, image attributes, image search

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Last update 2011-10-18