Content-Based Image Retrieval Using Wavelet Packets and Fuzzy Spatial Relations Minakshi Banerjee and Malay K. Kundu Machine Intelligence Unit, Indian Statistical Institute 203, B.T. Road, Kolkata 700 108, India {minakshi r, malay}@isical.ac.in Abstract. This paper proposes a region based approach for image re- trieval. We develop an algorithm to segment an image into fuzzy regions based on coefficients of multiscale wavelet packet transform. The wavelet based features are clustered using fuzzy C-means algorithm. The final cluster centroids which are the representative points, signify the color and texture properties of the preassigned number of classes. Fuzzy Topo- logical relationships are computed from the final fuzzy partition matrix. The color and texture properties as indicated by centroids and spatial relations between the segmented regions are used together to provide overall characterization of an image. The closeness between two images are estimated from these properties. The performance of the system is demonstrated using different set of examples from general purpose image database to prove that, our algorithm can be used to generate meaningful descriptions about the contents of the images. 1 Introduction Effective searching of relevant images using information derived from the visual contents (color, texture, shape etc.) is the focus of interest for most research on image databases. In the recent past, Content-Based Image Retrieval (CBIR) techniques became popular [1], [2], [3], [4],[5], [6], [7], [8] for retrieving relevant images from an image database by measuring similarity between the automat- ically derived features (color, texture, shape etc. ) of the query image and the images stored in the database [5]. But even with the most sophisticated design, it is often not possible to achieve satisfactory results, because the image features may convey different meanings under different context (semantic gap). There are ongoing efforts by the researchers for bridging the gap between human intuitive understanding and information derived from image features. Apparently different set of features are suitable for different purposes. For ex- ample, shape related features are not suitable to extract textured pictures only. The features like color, texture, shape as well as the spatial relationship between the individual regions play a significant role in depicting the overall meaning as- sociated with the scene. The properties of individual regions can be coupled with spatial relationships between them, to provide more realistic matching between two images. Methodologies to compute spatial relationships of the objects have P. Kalra and S. Peleg (Eds.): ICVGIP 2006, LNCS 4338, pp. 861–871, 2006. c  Springer-Verlag Berlin Heidelberg 2006