Compressed Domain Forensic Marking for Digital Content

Solution Overview

Problem

Existing digital watermarking systems face inefficiencies in embedding and detecting forensic marks in compressed domain content, particularly due to the need for decompression and re-compression, which degrades quality and is computationally expensive, and are vulnerable to collusion and differential analysis attacks.

Innovation Solution

A method for embedding forensic marks directly in the compressed domain by selecting and assembling tributary segments with unique watermark symbols, using a preprocessing module to generate and store these segments, and a marking module to create forensically marked content without decompressing, while incorporating distortions to obstruct differential analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If forensic marks are embedded by decompressing and re-compressing host content, then watermark embedding can be performed, but quality degrades and computational cost increases

Engineering Contradiction:

Improvewatermark embedding capabilityVSAvoidcontent quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent uses compressed domain representations (DCT coefficients, transform domains) as an intermediary to perform watermark embedding without full decompression. The watermark is embedded in the compressed coefficients directly, avoiding the quality degradation and computational cost of decompressing and re-compressing the entire content.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical decompress-recompress process with direct mathematical operations in the compressed domain. Instead of converting compressed content back to time/space domain and then re-compressing, the system performs watermark embedding through direct manipulation of compressed coefficients using spread spectrum or other embedding techniques.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If forensic marks are embedded by decompressing and re-compressing host content, then watermark embedding can be performed, but computational expense increases

Engineering Contradiction:

Improvewatermark embedding capabilityVSAvoidcomputational cost

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses compressed domain representations (DCT coefficients, transform domains) as an intermediary to perform watermark embedding without full decompression. The watermark is embedded in the compressed coefficients directly, avoiding the quality degradation and computational cost of decompressing and re-compressing the entire content.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical decompress-recompress process with direct mathematical operations in the compressed domain. Instead of converting compressed content back to time/space domain and then re-compressing, the system performs watermark embedding through direct manipulation of compressed coefficients using spread spectrum or other embedding techniques.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If traditional watermarking systems are used, then forensic marks can be embedded, but systems are vulnerable to collusion and differential analysis attacks

Engineering Contradiction:

Improvewatermark detectionVSAvoidvulnerability to attacks

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary distortion to the host content before watermark embedding. This distortion is designed to obstruct differential analysis attacks by making it difficult for attackers to identify and remove watermarks through comparison of multiple copies. The distortion is applied in the compressed domain to maintain efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent transforms the watermark embedding process from the time/space domain to the frequency/compressed domain. This parameter change in the domain of operation provides inherent security benefits, as attacks designed for time/space domain watermarks become ineffective. The system embeds watermarks in transform coefficients rather than raw samples.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8681978B2Efficient and secure forensic marking in compressed domain

Publication Date: 2014.03.25 VOBILE INC

AI summary

Methods, devices, and computer program products enable the embedding of forensic marks in a host content that is in compressed domain. These and other features are achieved by preprocessing of a host content to provide a plurality of host content versions with different embedded watermarks that are subsequently compressed. A host content may then be efficiently marked with forensic marks in response to a request for such content. The marking process is conducted in compressed domain, thus reducing the computational burden of decompressing and re-compressing the content, and avoiding further perceptual degradation of the host content. In addition, methods, devices and computer program products are disclosed that obstruct differential analysis of such forensically marked content.