Automatiska bildförslag till nyhetsartiklar

Multimodal machine learning is a subfield of machine learning that aims to relate data from different modalities, such as texts and images. One of the many applications that could be built upon this technique is an image retrieval system that, given a text query, retrieves suitable images from a database. In this thesis, a retrieval system based on canonical correlation is used to suggest images for news articles. Different dense text representations produced by Word2vec and Doc2vec, and image representations produced by pre-trained convolutional neural networks are explored to find out how they affect the suggestions. Which part of an article is best suited as a query to the system is also studied. Also, experiments are carried out to determine if an article's date of publication can be used to improve the suggestions. The results show that Word2vec outperforms Doc2vec in the task, which indicates that the meaning of article texts are not as important as the individual words they consist of. Furthermore, the queries are improved by rewarding words that are particularly significant