Neural Event-Camera Representation Using 3D Voxel Grids

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Solution Overview

Problem

Existing data-processing algorithms for event cameras lag behind frame-based algorithms in performance metrics, and raw event data are inefficient for array-based neural networks due to spatiotemporal sparsity, leading to challenges in processing and bandwidth requirements.

Innovation Solution

A learning-based framework using neural networks, including MLP, tensor decomposition, and hash encoding, to represent event voxel grids, enabling efficient conversion and processing of event-camera data, which can be used for downstream tasks and bandwidth-limited communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If event-camera data is processed using traditional frame-based algorithms, then bandwidth requirements are reduced and temporal resolution is improved, but processing performance lags behind frame-based algorithms

Engineering Contradiction:
Improvebandwidth requirementsVSAvoidprocessing performance
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent transforms event-camera data from its native sparse format into a dense voxel grid representation in 3D space (x, y, time dimensions). This parameter transformation enables the data to be processed by standard CNN architectures, achieving frame-based algorithm performance while maintaining event-camera advantages in bandwidth efficiency and temporal resolution.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediate voxel grid representation as a mediator between raw event data and neural network processing. This intermediate format bridges the gap between sparse event data and dense frame-based processing requirements, allowing standard CNNs to effectively process event-camera data without direct modification to the algorithms.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If raw event data is directly input to array-based neural networks, then data sparsity is preserved, but processing efficiency decreases due to spatiotemporal sparsity

Engineering Contradiction:
Improvedata sparsity preservationVSAvoidprocessing efficiency
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent adds a temporal dimension to the spatial event data, transforming 2D sparse event coordinates into 3D voxel grids (x, y, time). This dimensional transformation consolidates spatiotemporal sparsity into a structured format that neural networks can efficiently process while preserving all original information through the time dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent merges multiple sparse events occurring at different times and locations into a unified voxel grid structure. By combining spatial and temporal information into a single dense representation, the approach enables efficient batch processing by neural networks while maintaining the integrity of individual event characteristics.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If event-camera data is converted to voxel grid representation, then neural network processing efficiency is improved, but model size increases

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidmodel size
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the voxel grid processing into distinct computational stages: event-to-voxel conversion, neural network processing, and output generation. This segmentation allows for optimized memory management and computational efficiency, reducing the practical model size requirements while maintaining high processing efficiency.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4700714A1Neural representation for event-camera data
Publication Date: 2026.02.25 DOLBY LABORATORIES LICENSING CORP
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AI summary

Methodology for generating a neural representation of event-camera data. In some examples, a method of representing event-camera data includes converting a set of the event-camera data into a corresponding set of voxel data for a voxel grid in a three-dimensional space in which first and second dimensions correspond to first and second spatial coordinates of an image frame, and a third dimension corresponds to time. The method further includes training a neural network to represent the voxel grid.