Learning crop regions for content-aware generation of thumbnail images

We propose a model for automatically cropping images based on a diverse set of content and spatial features. We approach this by extracting pixel-level features and aggregating them over possible crop regions. We then learn a regression model to predict the quality of the crop regions, via the degree to which they would overlaps with human-provided crops from these input features. Candidate images can then be cropped based an exhaustive sweep over candidate crop regions, where each region is scored and the highest-scoring region is retained. The system is unique in its ability to incorporate a variety of pixel-level importance cues when arriving at a final cropping recommendation. We test the system on a set of human-cropped images with a large set of features. We find that the system outperforms baseline approaches, particularly when the aspect ratio of the image is very different from the target thumbnail region.