1. Fast Image Retrieval Using Color-spatial Information NTUT CSIE D.W. Lin 2003.7.15

2. Preliminary  Incorporating spatial information with color  To utilize color-spatial information: – The representation of color-spatial information (feature vector) and similarity measure – The speedy retrieval of relevant image (indexing mechanism)

3. Color-spatial information  Single-colored clusters: – Bounds a homogeneous region (in some color) in an image – Represented as (color, coordinates), i.e., a cluster is simply indicated as a rectangle  Multi-tier indexing mechanism(SMAT) – Each layer corresponds to a feature, and can be indexing by any known mechanism

4. Extraction of color-spatial info.  Three phases: – Extracts a set of dominant colors: from the sorted color histogram – Determines a set of clusters for each of the dominant color: max. entropy method (mem) – Ranks clusters regardless its color, picks Cl largest (dominant) clusters as color-spatial info. of image

5. Similarity measure  For image g 1 and g 2  N c : number of colors