Learning group-based dictionaries for discriminative image representation

• A visual concept network is built to characterize the inter-concept correlations.
• An automatic algorithm is proposed for identifying the visually similar groups.
• A new algorithm is developed to learn group-based discriminative dictionaries.
• A structural method is developed for classifier training and image classification.
• Our proposed algorithms are evaluated on multiple popular visual benchmarks.

Dictionary learning is a critical issue for achieving discriminative image representation in many computer vision tasks such as object detection and image classification. In this paper, a new algorithm is developed for learning discriminative group-based dictionaries, where the inter-concept (category) visual correlations are leveraged to enhance both the reconstruction quality and the discrimination power of the group-based discriminative dictionaries. A visual concept network is first constructed for determining the groups of visually similar object classes and image concepts automatically. For each group of such visually similar object classes and image concepts, a group-based dictionary is learned for achieving discriminative image representation. A structural learning approach is developed to take advantage of our group-based discriminative dictionaries for classifier training and image classification. The effectiveness and the discrimination power of our group-based discriminative dictionaries have been evaluated on multiple popular visual benchmarks.