Exploring Different Preposition Sets, Models and Feature Sets in Automatic Generation of Spatial Image Descriptions

In this paper we look at the question of how to create good automatic methods for generating descriptions of spatial relationships between objects in images. In particular, we investigate the impact of varying different aspects of automatic method development, including using different preposition sets, models and feature sets. We find that optimising the preposition set improves previous best Accuracy from 46.2 to 50.2. Feature set optimisation further improves best Accuracy from 50.2 to 53.25. Naive Bayes models outperform SVMs and decision trees under all conditions tested. The utility of individual features depends on the model used, but the most useful features tend to capture a property pertaining to both objects jointly.