Queries by browsing or comparing may run efficiently on icons without having to access the original observational data. However, they generally cannot be used on astronomical images because of their high noise sensitivity. The scheme in Figure 1 depicts a management system supporting operations required for content-based information retrieval. An example of a spectrogram is shown on the left of Figure 2. The design of a system supporting content-based queries.
Ovals symbolize software parts.
The feature extractor and the classifier. In the following, algorithms for feature extraction and selection are summarized. An image is assumed to be an array of n elements, with columns and rows. Regions which passed the selection build the actual icon. Many automatic classification methods have been studied in the context of astronomy.