2. The similarity calculation device as claimed in claim 1 , wherein: the second media data is constituted with a plurality of media data; the single score calculation device calculates the single score for each of the media data contained in the second media data; the inter-media similarity calculation device calculates the inter-media similarity for each of the media data; and the query similarity calculation device calculates the similarity between the first media data and the text query by using the inter-media similarity and the single scores of each of the media data.
2. The similarity calculation device as claimed in claim 1 , wherein: the second media data is constituted with a plurality of media data; the single score calculation device calculates the single score for each of the media data contained in the second media data; the inter-media similarity calculation device calculates the inter-media similarity for each of the media data; and the query similarity calculation device calculates the similarity between the first media data and the text query by using the inter-media similarity and the single scores of each of the media data. 3. The similarity calculation device as claimed in claim 2 , wherein the query similarity calculation device calculates the similarity between the first media data and the text query by taking a weighted sum of the single scores of each of the media data in accordance with the inter-media similarity between each of the media data contained in the second media data.