Spectral Filter Sweep for Event-Based Sensor Data Compression

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Solution Overview

Problem

Current spectral imaging systems face challenges in achieving high spatial, temporal, and spectral accuracy due to the high data volume generated, which leads to reduced spatial image accuracy and temporal sampling limitations, especially when using mosaicking techniques with color filters.

Innovation Solution

A spectral filter with variable transmission, an event-based imaging sensor that generates measurement events based on filter responses, and a processor that controls the filter transmission to sweep over wavelengths, allowing for the estimation of the observed spectrum through measurement events and filter transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If mosaicking with color filters is applied to reduce data volume, then data compression is achieved, but spatial image accuracy deteriorates

Engineering Contradiction:
Improvedata volumeVSAvoidspatial image accuracy
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies a dynamic spectral filter that continuously sweeps through different wavelengths over time, rather than using static color filters. This temporal modulation of filter transmission allows each pixel to capture spectral information across multiple wavelengths sequentially, achieving data compression while maintaining spatial resolution through the time-varying measurement approach

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent transforms the spectral imaging problem from a spatial sampling challenge to a temporal measurement problem. By adding the time dimension through continuous spectral filtering, the system captures spectral information dynamically, converting spatial accuracy requirements into temporal sampling requirements that can be satisfied without sacrificing spatial resolution

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

2Measurement precision

If high precision spectral measurements are captured, then spectral accuracy is improved, but data bandwidth increases

Engineering Contradiction:
Improvespectral accuracyVSAvoiddata bandwidth
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the necessary spectral information by using a sweeping filter that sequentially probes different wavelengths. Instead of capturing the complete spectrum simultaneously for every pixel, the system extracts spectral measurements over time, reducing the instantaneous data bandwidth requirement while maintaining spectral accuracy through the temporal sequence of measurements

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the filter transmission parameter dynamically over time, sweeping through different wavelength ranges. This temporal variation in filter characteristics allows the system to capture spectral information with high precision while reducing data bandwidth, as each pixel outputs a time-varying signal that encodes spectral information rather than simultaneous multi-wavelength data

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If globally changing color filters are used, then spectral information is improved, but temporal sampling limitation worsens

Engineering Contradiction:
Improvespectral informationVSAvoidtemporal sampling limitation
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements periodic spectral filtering where the filter transmission sweeps through wavelengths in a continuous, repeating cycle. This periodic modulation of the filter allows the system to capture spectral information at multiple time points within each cycle, improving spectral measurement precision while mitigating temporal sampling limitations through the repeated measurement opportunities provided by each sweep cycle

Inventive Principle:
Principle #19Periodic action

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

This approach enables efficient data compression and reconstruction of spectral scenes with high spatial and spectral resolution, overcoming the limitations of traditional systems by asynchronously recording intensity changes and utilizing numerical reconstruction methods like Tikhonov regularization or compressive sensing.

Implementation Method 1

a spectral filter (26) with a variable spectral filter transmission (FT(λ))

Methodology Applied
Scientific EffectSpectral filtering: Filter (optical)

Implementation Method 2

an event-based imaging sensor (27) configured to produce measurement events (y1, y2, . . . , yn) which correspond to a change in a filter response (Y(t)) that is generated by an observed spectrum (X(λ))

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentUS11204279B2Apparatus and method
Publication Date: 2021.12.21 SONY SEMICON SOLUTIONS CORP
  • US11204279B2 patent drawing
  • US11204279B2 patent drawing
  • US11204279B2 patent drawing

AI summary

An apparatus comprising a spectral filter (26) with a variable spectral filter transmission (FT(λ)); an event-based imaging sensor (27) configured to produce measurement events (y1, y2, . . . , yn) which correspond to a change in a filter response (Y(t)) that is generated by an observed spectrum (X(λ)), and a processor (28) configured to control the filter transmission (FT(λ)) of the spectral filter (26) so that it sweeps over wavelength (λ) with time (t), and to generate an estimation (X*(λ)) of the observed spectrum (X(λ)) based on the measurement events (y1, y2, . . . , yn) that correspond to the filter response (Y(t)) and based on the filter transmission (FT(λ)).