Indirect ToF Motion Compensation for Accurate Depth Mapping

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Solution Overview

Problem

Conventional time-of-flight (ToF) cameras fail to provide accurate 3D motion information and suffer from significant motion artifacts in dynamic scenes, as they do not explicitly consider scene or camera motion, leading to degraded depth and intensity estimates.

Innovation Solution

A system and method for concurrent depth and motion estimation using indirect time-of-flight (I-ToF) imaging, which involves emitting modulated light, generating correlation images, and processing these images to determine lateral and axial motion, thereby refining depth and intensity estimates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional ToF cameras are used for 3D imaging, then compact form-factor and low computational complexity are achieved, but motion artifacts occur and 3D motion information is not provided

Engineering Contradiction:

Improvecomputational complexityVSAvoiddepth estimation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by transitioning from static scene assumptions to dynamic scene modeling. The system explicitly models camera motion and scene motion as time-varying parameters, using temporal derivatives and motion compensation techniques to handle dynamic environments. This allows the ToF camera to maintain accuracy in dynamic scenes while keeping the hardware architecture relatively simple.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback mechanisms by continuously estimating motion parameters from captured images and using these estimates to compensate for motion effects in subsequent processing steps. The system iteratively refines depth and motion estimates using feedback from intensity changes and correlation image analysis, improving measurement precision without requiring complete redesign of the imaging system.

Inventive Principle:

Principle #23Feedback

2Productivity

If conventional ToF cameras process images without motion consideration, then processing speed is maintained, but motion artifacts degrade depth and intensity estimates

Engineering Contradiction:

Improveimage processing speedVSAvoiddepth estimation reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-processing captured images to generate motion estimates and motion compensation parameters before final depth calculation. The system performs preliminary correlation image analysis and intensity change detection to prepare motion compensation data, which is then applied in subsequent depth estimation steps, maintaining processing efficiency while improving reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the image processing pipeline into distinct modules: correlation image generation, motion estimation, motion compensation, and depth calculation. Each module processes specific aspects of the data independently, allowing optimized processing speeds for each stage while ensuring reliable overall results through coordinated operation of segmented processing steps.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If ToF cameras do not explicitly model scene motion, then device complexity is reduced, but 3D motion information cannot be provided

Engineering Contradiction:

Improvemotion modeling complexityVSAvoidmotion information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent applies universality by designing a multi-functional processing system that simultaneously extracts multiple types of information (depth, motion, intensity) from the same captured data using a unified approach. The correlation image analysis and intensity change detection mechanisms serve multiple purposes: estimating both camera and scene motion, generating depth maps, and compensating for motion effects, thereby avoiding information loss without proportionally increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables motion-free depth and intensity estimation with improved signal-to-noise ratio, facilitating high-quality 3D geometry, intensity, and motion estimation in dynamic scenes using a single I-ToF camera.

Implementation Method 1

indirect time-of-flight imaging

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 2

cause the light source to emit modulated light toward the scene, with modulation based on the first signal

Methodology Applied

Scientific EffectLight modulation: Phase Modulation

Data Source

PatentUS20260004443A1Systems, methods, and media for concurrent depth and motion estimation using indirect time of flight imaging

Publication Date: 2026.01.01 WISCONSIN ALUMNI RES FOUND

AI summary

In accordance with some embodiments, systems, methods and media for concurrent depth and motion estimation using indirect time-of-flight imaging are provided. In some embodiments, the system comprises: a processor configured to: receive a first set of correlation images generated by an I-ToF camera; receive a second set of correlation images generated; generate a first and second blurred intensity image using the first and second set of correlation images, respectively; determine estimated lateral motion in the scene based on a distribution of intensity values in the first and second blurred images; and determine a first and second depth map for the scene based on the first and second sets of correlation images, respectively, and based on the estimated lateral motion in the scene.