Automatic Ranking of Iconic Images

We define an iconic image for an object category (e.g. eiffel tower) as an image with a large clearly delineated instance of the object in a characteristic aspect. We show that for a variety of objects such iconic images exist and argue that these are the images most relevant to that category. Given a large set of images noisily labeled with a common theme, say a Flickr tag, we show how to rank these images according to how well they represent a visual category. We also generate a binary segmentation for each image indicating roughly where the subject is located. The segmentation procedure is learned from data on a small set of iconic images from a few training categories and then applied to several other test categories. We rank the segmented test images according to shape and appearance similarity against a set of 5 hand-labeled images per category. We compute three rankings of the data: a random ranking of the images within the category, a ranking using similarity over the whole image, and a ranking using similarity applied only within the subject of the photograph. We then evaluate the rankings qualitatively and with a user study.