Quantized CIELab* space and encoded spatial structure for scalable indexing of large color image archives

This paper presents a scalable approach for content-based searching and browsing of color image archives using segmented color-layout and spatial structure information. The segmented color layout is computed using quantized CIE-Lab* space, and encoded quadtrees have been used to preserve and represent the structural information. Our careful choice of feature space and associated indexing provides a scalable content-based indexing and retrieval (CBIR) system, where query time is relatively independent of the database size and only depends on the number of images similar to the query image. A sample query in our system takes less than 25 msec on a Pentium 233 MHz machine using a database of 5000 512×512 size images. This query time is orders of magnitude less than the time on available commercial and research prototypes. Experimental results are also presented showing the quality and efficiency of the indexing system