Distributed index system and method based on multi-length signature files

A distributed index method based on multi-length signature files, the distributed index method comprising:

• extracting N-dimensional feature vectors from multimedia object;
• establishing a tree-based distributed index through a random sampling from the extracted N-dimensional feature vectors;
• calculating a cluster size for each leaf node of the established distributed index tree, and determining a signature length according to the calculated cluster size;
• determining a computing node for each leaf node of the distributed index tree;
• and
• generating signatures having the determined length at the computing node and storing the generated signatures with matching to the N-dimensional feature vectors.

A distributed index method based on multi-length signature files, the distributed index method comprising:

• extracting feature vectors from a stored multimedia object;
• searching a distributed index tree based on the extracted feature vectors, determining candidate leaf nodes having a similar value, and requesting a similarity search;
• generating signatures managed at the candidate leaf nodes determined upon the similarity search request, and determining candidate signatures by sequentially searching stored signature files based on the generated signatures;
• and
• searching feature vectors corresponding to the candidate signatures determined at the candidate leaf nodes, and determining final candidate feature vectors.