1. An AIU structure synthesizer of semantic information from multimedia non-textual documents comprising: an error corrector for receiving raw AIU's extracted from said non-textual documents and for correcting errors in said raw AIU's; a primitive identifier connected to said error corrector, for assigning semantics to outputs of said error corrector; a basic synthesizer connected to said primitive identifier, for grouping related outputs of said primitive identifier; and, an abstract synthesizer connected to said basic synthesizer, for grouping related outputs of said basic synthesizer.