Rolling Shutter Frame Authentication Using Motion Distortion Checks

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Solution Overview

Problem

Existing camera surveillance systems face challenges in ensuring the authenticity and integrity of video streams captured by rolling shutter image sensors, as tampering can occur before encryption, which current signing methods do not account for.

Innovation Solution

A method to verify image data frames using a rolling shutter image sensor by detecting moving objects, estimating their speed, measuring and calculating the rolling shutter effect, and comparing the measured effect to the expected effect to determine authenticity, with outputs indicating suspect frames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If video streaming is signed with encryption algorithm to ensure authenticity, then data security is improved, but tampering can still occur prior to signing which undermines the effectiveness of the signing mechanism

Engineering Contradiction:

Improvedata securityVSAvoidtampering before signing

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by verifying image data authenticity before the video streaming signing process. The system detects moving objects, estimates their speed, measures the rolling shutter effect, and compares it against expected values to identify tampered frames prior to encoding and signing, thus preventing compromised data from entering the signed stream

Inventive Principle:

Principle #10Preliminary action

2Productivity

If rolling shutter image sensor is used to capture video streams, then image capture capability is improved, but rolling shutter effect causes distortions in moving objects that complicate authenticity verification

Engineering Contradiction:

Improveimage capture capabilityVSAvoidauthenticity verification accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by transforming the rolling shutter effect from a distortion into a verifiable parameter. Instead of treating the effect as noise, the system measures the actual pixel shift caused by the rolling shutter and compares it against the expected shift calculated from object speed and readout timing, using this parameter comparison to detect tampering

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by creating a closed-loop verification system. The system continuously measures the rolling shutter effect in captured frames, compares it against expected values derived from object motion analysis, and uses this feedback to identify and flag suspicious frames, thereby maintaining verification accuracy despite the inherent distortions

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250386116A1Rolling shutter image data verification

Publication Date: 2025.12.18 AXIS

AI summary

The present system and method generally relate to the field of camera surveillance, and in particular to verifying image data in image data frames captured by a rolling shutter image sensor of a camera.