QUERY EXPANSION OF PROPERTIES FOR VIDEO RETRIEVAL

1 . A computer implemented method for retrieving video clips from a database, comprising the steps of:

retrieving in an initial query from a video collection based on a search term;

receiving a user selection of at least one video clip from a first set of video clips corresponding to the search term;

associating at least one visual attribute of the selected video clip with the search term;

receiving the at least one search term from a user in a subsequent query;

determining a set of physical concepts based on the at least one search term;

mapping the set of physical concepts to a plurality of visual attributes;

searching the database for at least one video clip corresponding to the plurality of visual attributes;

identifying at least one video clip in the database having the plurality of visual attributes; and

returning a second set of video clips having the set of visual attributes to the user, the second set including the at least one video clip.

2 . The method of claim 1 , wherein the second set contains fewer video clips than the first set.

3 . The method of claim 1 , wherein said steps of determining a set of physical concepts and mapping the set of physical concepts are performed using a taxonomy and an inference engine.

4 . The method of claim 3 , further comprising the step of querying a plurality of collections of video clips in the database, wherein the range of values for a given visual attribute is the union of values that covers substantially all video clips having said given visual attribute across the plurality of collections of video clips.

5 . The method of claim 1 , wherein at least one of the plurality of visual attributes is derived from sensor metadata stored with at least one of the second set of video clips.

6 . The method of claim 1 , wherein at least one of the plurality of visual attributes is associated with the selected at least one video clip.

7 . The method of claim 1 , further comprising the steps of:

extracting at least one actual value of at least one of the plurality of visual attributes for which at least one default value has been assigned in the taxonomy;

associating with the at least one actual value at least one other visual attribute from the second set of video clips; and

annotating the taxonomy with the associated at least one other visual attribute.

8 . The method of claim 7 , further comprising the steps of:

receiving the at least one search term from the user;

determining a second set of physical concepts based on the at least one search term;

mapping the second set of physical concepts to a second plurality of visual attributes based on the annotated taxonomy;

searching the database for at least one video corresponding to the second plurality of visual attributes;

identifying at least one video clip in the database having the second plurality of visual attributes; and

returning a third set of video clips having the second plurality of visual attributes to the user, the third set including the at least one video clip.

9 . The method of claim 1 , wherein the third set contains fewer video clips than the second set.

10 . The method of claim 1 , further comprising the step of assigning a default value to at least one of the plurality of visual attributes, the default value being computed based on a collection of training video clips.

11 . The method of claim 1 , further comprising the step of pre-computing minimum and maximum values of at least one of plurality of visual attributes.

12 . The method of claim 1 , wherein at least one value corresponding to at least one of the plurality of visual attributes is derived from metadata contained within a collection of training video clips.

13 . The method of claim 1 , wherein the step of determining a set of physical concepts further comprising the step of finding synonyms of the search term for use in determining the set of physical concepts.

14 . An apparatus for retrieving video clips from a database, comprising:

a processor configured for executing instructions comprising the steps of:

retrieving in an initial query from a video collection based on a search term;

receiving a user selection of at least one video clip from a first set of video clips corresponding to the search term;

associating at least one visual attribute of the selected video clip with the search term;

receiving the at least one search term from a user in a subsequent query;

determining a set of physical concepts based on the at least one search term;

mapping the set of physical concepts to a plurality of visual attributes;

searching the database for at least one video clip corresponding to the plurality of visual attributes;

identifying at least one video clip in the database having the plurality of visual attributes; and

returning a second set of video clips having the set of visual attributes to the user, the second set including the at least one video clip.

15 . The apparatus of claim 14 , wherein the second set contains fewer video clips than the first set.

16 . The apparatus of claim 14 , wherein said steps of determining a set of physical concepts and mapping the set of physical concepts are performed using a taxonomy and an inference engine.

17 . The apparatus of claim 16 , wherein the processor is further configured for executing instructions comprising the step of querying a plurality of collections of video clips in the database, wherein the range of values for a given visual attribute is the union of values that covers substantially all video clips having said given visual attribute across the plurality of collections of video clips.

18 . The apparatus of claim 14 , wherein at least one of the plurality of visual attributes is derived from sensor metadata stored with at least one of the second set of video clips.

19 . The apparatus of claim 14 , wherein at least one of the plurality of visual attributes is associated with the selected at least one video clip.

20 . The apparatus of claim 14 , wherein the step further comprises the steps of:

extracting at least one actual value of at least one of the plurality of visual attributes for which at least one default value has been assigned in the taxonomy;

associating with the at least one actual value at least one other visual attribute from the second set of video clips; and

annotating the taxonomy with the associated at least one other visual attribute.

21 . The apparatus of claim 20 , wherein the processor is further configured for executing instructions comprising the steps of:

receiving the at least one search term from the user;

determining a second set of physical concepts based on the at least one search term;

mapping the second set of physical concepts to a second plurality of visual attributes based on the annotated taxonomy;

searching the database for at least one video corresponding to the second plurality of visual attributes;

identifying at least one video clip in the database having the second plurality of visual attributes; and

returning a third set of video clips having the second plurality of visual attributes to the user, the third set including the at least one video clip.

22 . The apparatus of claim 21 , wherein the third set contains fewer video clips than the second set.

23 . A computer-readable medium carrying one or more sequences for retrieving video clips from a database, wherein execution of the one of more sequences of instructions by one or more processors causes the one or more processors to perform the steps comprising:

retrieving in an initial query at least one video clip from a video collection based on a search term;

receiving a user selection of at least one video clip from a first set of video clips corresponding to the search term;

associating at least one visual attribute of the selected video clip with the search term;

receiving the at least one search term from a user in a subsequent query;

determining a set of physical concepts based on the at least one search term;

mapping the set of physical concepts to a plurality of visual attributes;

searching the database for at least one video clip corresponding to the plurality of visual attributes;

identifying at least one video clip in the database having the plurality of visual attributes; and

returning a second set video clips having the set of visual attributes to the user, the second set including the at least one video clip.

24 . The computer-readable medium of claim 23 , wherein the second set contains fewer video clips than the first set.

25 . The computer readable medium of claim 23 , wherein said steps of determining a set of physical concepts and mapping the set of physical concepts are performed using a taxonomy and an inference engine.

26 . The computer readable medium of claim 23 , wherein the one or more processors are further configured to perform the step comprising querying a plurality of collections of video clips in the database, wherein the range of values for a given visual attribute is the union of values that covers substantially all video clips having said given visual attribute across the plurality of collections of video clips.

27 . The computer readable medium of claim 23 , wherein at least one of the plurality of visual attributes is derived from sensor metadata stored with at least one of second set of video clips.

28 . The computer readable medium of claim 23 , wherein at least one of the plurality of visual attributes is associated with the selected at least one video clip.

29 . The computer readable medium of claim 23 , further comprises the steps of:

extracting at least one actual value of at least one of the plurality of visual attributes for which at least one default value has been assigned in the taxonomy;

associating with the at least one actual value at least one other visual attribute from the second set of video clips; and

annotating the taxonomy with the associated at least one other visual attribute.

30 . The computer readable medium of claim 29 , wherein the one or more processors are further configured to perform the steps comprising:

receiving the at least one search term from the user;

determining a second set of physical concepts based on the at least one search term;

mapping the second set of physical concepts to a second plurality of visual attributes based on the annotated taxonomy;

searching the database for at least one video corresponding to the second plurality of visual attributes;

identifying at least one video clip in the database having the second plurality of visual attributes; and

returning a third set of video clips having the second plurality of visual attributes to the user, the third set including the at least one video clip.

31 . The computer-readable medium of claim 30 , wherein the third set contains fewer video clips than the second set.