Improved Image Caption Rating - Datasets, Game, and Model.

How well a caption fits an image can be difficult to assess due to the subjective nature of caption quality. What is a caption? We investigate this problem by focusing on image-caption ratings and by generating high quality datasets from human feedback with gamification. We validate the datasets by showing a higher level of inter-rater agreement, and by using them to train custom machine learning models to predict new ratings. Our approach outperforms previous metrics - the resulting datasets are more easily learned and are of higher quality than other currently available datasets for image-caption rating.