An Image Generalization Technique – The Key to Finding Similar Images

Wojciech Tarnawski, Roman Pawlikowski, Krzysztof Ociepa (Wroclaw University of Technology, Poland)

Abstract:

We present the complete image retrieval system that includes a novel segmentation technique tailored to acquiring a very generalized view and more reliable with annotations assigned to analyzed natural images. The philosophy behind our approach to finding similar images is introduced at the beginning of the presentation. The segmentation method follows the principle of clustering the regions visible in the image to receive most meaningful image regions. The concept is based on the multiscale approach (anisotropic diffusion) followed by the procedure of mean-shift segmentation. The information gained while performing diffusion with subsequent meanshift segmentation results are accumulated, and a new image which visualizes the generalized effect is produced. Next, to attain the desired level of generalization, smaller regions in the image are merged into greater ones by taking into consideration their areas and co-occurrence in the planar space of the image. This unifying process produces a very high-level view of the image, with only a small number of regions to consider while performing feature extraction. The features extracted, which include color, texture as well as shape , are a subset of the MPEG-7 visual descriptors. The actual goal of finding similar images consists of comparing the regions of a query image with the regions of images held in the database, and stating their level of similarity. Two propositions of similarity metrics between images are presented. Many examples illustrating the intermediate results obtained while performing the above mentioned