Abstract
This paper proposes structural features for image representation and retrieval. Among various structural features are the water-filling features, which can be efficiently extracted from edge maps to represent the edge/structural information in the image. The advantages of the feature extraction algorithm include efficiency - it is a linear-time algorithm; and effectiveness - multiple feature components corresponding to different human perceptions can be extracted simultaneously. Since edge maps are usually not scale invariant, also proposed are the multiscale feature extraction and cross-scale matching schemes. Experiments show that the new features can catch salient edge/structure information and cross-scale matching improves the retrieval performance in a real-world image retrieval system.