Browsing large satellite and aerial photographs

Image content based retrieval in the Alexandria digital library project has focussed on texture and color features for querying the database. A robust texture feature extraction algorithm and a fast segmentation scheme have been developed. The texture features are computed by filtering the image with a bank of Gabor filters. This is followed by a clustering scheme to create a texture based feature dictionary, which is then used to search and retrieve similar looking patterns from other images. Experimental results demonstrate the robustness of the overall system in searching over a large collection of airphotos and in selecting a surprisingly diverse collection of geographic features such as housing developments, parking lots, highways, and airports.