Caltech-UCSD Birds 200 (CUB-200) is a challenging image dataset annotated with 200 bird species. It was created to enable the study of subordinate categorization, which is not possible with other popular datasets that focus on basic level categories (such as PASCAL VOC, Caltech-101, etc). The images were downloaded from the website Flickr and filtered by workers on Amazon Mechanical Turk. Each image is annotated with a bounding box, a rough bird segmentation, and a set of attribute labels. forehead_color black black black breast_pattern solid solid solid breast_color white white white head_pattern plain capped plain back_color white white black wing_color grey/white grey white leg_color orange orange orange size medium large medium bill_shape needle dagger dagger wing_shape pointed tapered long