Multimedia databases contain an increasing number of videos that are not easily semantically accessed. Among the useful indices that can be extracted from the soundtrack, the presence of a keyword at some place plays a prominent role. This paper deals with the specificities of such a keyword spotter and the enhancements brought to our previous technique (1996) based on frame labeling. To be useful, such a keyword spotter has to be speaker-independent. Moreover, it has to be able to detect any word from an open vocabulary. This directly implies the use of a phonemic representation of the word. These constraints usually lead to an excessively time-consuming tool. The division of the indexing process into two parts-the first one off-line, the second one at query time-allows a faster response.
['Philippe Gelin', 'Christian Wellekens']
Keyword spotting enhancement for video soundtrack indexing