The Chinese University of Hong Kong Steven C.H. Hoi†, Wei Liu†, Michael R. Lyu†, Wei-Ying Ma‡ †The Chinese University of Hong Kong ‡Microsoft Research Asia • Distance metrics are essential for image retrieval. • Learning distance metrics from contextual constraints is critical to bridge the semantic gaps of image retrieval. • Traditional distance metric learning usually study . linear distance metrics, which may not be effective for image retrieval. • A new distance metric learning method is proposed for image retrieval. • We developed two algorithms, Discriminative Component Analysis (DCA) and Kernel DCA for learning metrics from pairwise constraints. • Empirical evaluations have been performed for image g retrieval. Main Ideas • Improving Relevance Component Analysis (RCA) by using the dissimilar contextual constraints. • Looking L ki for f the th mostt di discriminative i i ti transformation t f ti for metric learning. Covariance matrix between data chunks Covariance matrix within data chunks Learning the optimal transformation 20 15 10 5 0 −5 −10 −15 −20 −20 −15 −10 −5 0 5 10 15 20 (a) Original Data Space 20 (a) “Dogs” retrieval 19.5 19 (b) “Butterfly” retrieval (c) “Roses” retrieval 18.5 18 17.5 17 16.5 20 0 −20 −10 0 20 10 (b) Space via Kernel 0 −1 −2 −3 −4 −5 −6 −7 Experimental results on the 20-Cat dataset (c) Embedding Space via KDCA −8 −3 −2 −1 0 1 2 3 The proposed DCA and Kernel DCA are promising for learning distance metrics from contextual constraints for image retrieval. CUHK and Microsoft Research Asia IEEE Computer Vision and Pattern Recognition 2006