On Tuesdays the USPTO issues new patents. Both of today's Spotlight Patents concern aspects of digital fingerprinting. Assigned to Akamai, the first patent deals with a dynamic multimedia fingerprinting system. Assigned to Advestigo, the second patent deals with techniques for indexing and identifying multimedia documents.
7,552,338, "Dynamic multimedia fingerprinting system," assigned to Akamai Technologies, Inc.
A dynamic multimedia fingerprinting system is provided. A user requests multimedia content from a Web cache server that verifies that the user is authorized to download the content. A custom fingerprint specific to the user is generated and dynamically inserted into the content as the content is delivered to the user. The custom fingerprint can be generated on the Web cache server or at the content provider's server. The system allows a content provider to specify where the custom fingerprint is inserted into the content or where the fingerprint is to replace a placeholder within the content.
7,552,120, "Method for indexing and identifying multimedia documents," assigned to Advestigo (FR).
The method of indexing multimedia documents comprises the following steps: a) for each document identifying and extracting terms t.sub.i constituted by vectors characterizing properties of the; b) storing terms t.sub.i in a term base comprising P terms; c) determining a maximum number N of desired concepts that group together the most pertinent terms t.sub.i; d) calculating the matrix T of distances between the terms t.sub.i of the term base; e) decomposing the set P of terms t.sub.i of the term base into N portions P.sub.j (1.ltoreq.j.ltoreq.N) such that P=P.sub.1.orgate. P.sub.2 . . . .orgate. P.sub.j . . . .orgate. P.sub.N, each portion P.sub.j comprising a set of terms t.sub.ij and being represented by a concept c.sub.j, the terms t.sub.i being distributed in such a manner that the terms that are farther apart are to be found in distinct portions P.sub.l, P.sub.m, and the terms that are closer together are to be found in the same portion P.sub.l; f) structuring the concept dictionary; and g) constructing a fingerprint base made up of the set of concepts c.sub.i representing the terms t.sub.i of the documents, each document being associated with a fingerprint that is specific thereto.