A method is for automatically indexing multimedia data archives and categorizing the files held therein and also to a client/server architecture in an image retrieval system for content-based searching for relevant files in a particular format and having a particular file structure. The parsed files stored in a data archive managed by the document management system are subjected to a feature extraction algorithm. The features obtained are then used for producing a binary-coded inverted index which includes elements of at least two attributes and holds context information which is held in these files and is needed for content-based image retrieval. If new files or files with an extended or modified content are stored in the data archive, then it involves a parsing algorithm and also an algorithm for automatically extracting features of these files being executed under event control during every storage process, in order to extend the inverted index by individual attributes or in order to update particular elements of already existing index attributes.