<title>WISE: a content-based Web image search engine</title>

This paper describes the development of a prototype of a Web Image Search Engine (WISE), which allows users to search for images on the WWW by image examples, in a similar fashion to current search engines that allow users to find related Web pages using text matching on keywords. The system takes an image specified by the user and finds similar images available on the WWW by comparing the image contents using low level image features. The current version of the WISE system consists of a graphical user interface (GUI), an autonomous Web agent, an image comparison program and a query processing program. The users specify the URL of a target image and the URL of the starting Web page from where the program will u0027crawlu0027 the Web, finding images along the way and retrieve those satisfying a certain constraints. The program then computes the visual features of the retrieved images and performs content-based comparison with the target image. The results of the comparison are then sorted according to a certain similarity measure, which along with thumbnails and information associated with the images, such as the URLs; image size, etc. are then written to an HTML page. The resultant page is stored on a Web server and is outputted onto the useru0027s Web browser once the search process is complete. A unique feature of the current version of WISE is its image content comparison algorithm. It is based on the comparison of image palettes and it therefore very efficient in retrieving one of the two universally accepted image formats on the Web, u0027gif.u0027 In gif images, the color palette is contained in its header and therefore it is only necessary to retrieve the header information rather than the whole images, thus making it very efficient.