Car Internet Dataset ( b ) Discovered Visual Subcategories and Learned Priors / Models Example Images Example Images Average Image Learned Prior Learned Detector Average Image Learned Prior Learned Detector

There have been some recent efforts to build visual knowledge bases from Internet images. But most of these approaches have focused on bounding box representation of objects. In this paper, we propose to enrich these knowledge bases by automatically discovering objects and their segmentations from noisy Internet images. Specifically, our approach combines the power of generative modeling for segmentation with the effectiveness of discriminative models for detection. The key idea behind our approach is to learn and exploit top-down segmentation priors based on visual subcategories. The strong priors learned from these visual subcategories are then combined with discriminatively trained detectors and bottom up cues to produce clean object segmentations. Our experimental results indicate state-of-the-art performance on the difficult dataset introduced by [29]. We have integrated our algorithm in NEIL for enriching its knowledge base [5]. As of 14 April 2014, NEIL has automatically generated approximately 500K segmentations using web data.