Color clustering for scene change detection and object tracking in video sequences

A method for clustering input vectors of a current set of input vectors in a sequence of sets of input vectors, in which the current set of input vectors corresponds to a current image frame being processed and the sequence of sets of input vectors corresponds to a sequence of image frames, the method comprising the steps of:

• identifying a set of prototype vectors for use in allocating the input vectors of the current set of input vectors into a plurality of clusters, wherein there is a one to one correspondence between the set of prototype vectors and the plurality of clusters;
• allocating the input vectors of the current set of input vectors into a plurality of clusters of input vectors, wherein during the step of allocating, the set of prototype vectors changes dynamically resulting in a modified set of prototype vectors after all input vectors of the current set of input vectors are allocated among the plurality of clusters, each cluster among the plurality of clusters having a number of allocated input vectors;
• after the step of allocating, discarding any prototype vector among the modified set of prototype vectors for which a corresponding cluster among the plurality of clusters has less than a specific number of allocated input vectors;
• and
• iteratively repeating the steps of identifying, allocating and discarding until the respective number of allocated input vectors for each cluster among the plurality of clusters stabilizes from a prior iteration to a current iteration.

A method for clustering color input vectors of a current set of color input vectors in a sequence of sets of color input vectors, in which the current set of color input vectors corresponds to color values of pixels within a current image frame being processed and the sequence of sets of color input vectors corresponds to color values of pixels within each one image frame of a sequence of image frames, the method comprising the steps of:

• identifying a set of prototype vectors for use in allocating the color input vectors of the current set of color input vectors into a plurality of clusters, wherein there is a one to one correspondence between the set of prototype vectors and the plurality of clusters;
• allocating the color input vectors of the current set of color input vectors into a plurality of clusters of color input vectors, wherein during the step of allocating the set of prototype vectors changes dynamically resulting in a modified set of prototype vectors after all color input vectors of the current set of color input vectors are allocated among the plurality of clusters, each cluster among the plurality of clusters having a number of allocated input vectors;
• and
• after the step of allocating, discarding any prototype vector among the modified set of prototype vectors for which a corresponding cluster among the plurality of clusters has less than a specific number of allocated color input vectors.