Hyperspectral Image Reconstruction Using Prism Dispersion Model

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Solution Overview

Problem

Current hyperspectral imaging systems are expensive, bulky, and difficult to handle due to the need for specialized hardware like collimating optics and coded masks, limiting their usability and spatial resolution.

Innovation Solution

A method for reconstructing hyperspectral images using a conventional DSLR camera and a simple glass prism, which eliminates the need for collimating optics and coded apertures, and employs a novel image formation model and calibration method to estimate spatially-varying dispersion and reconstruct spectral information from sparse dispersion cues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional hyperspectral imaging systems use collimating optics and coded masks, then spectral measurement capability is achieved, but device complexity and size increase significantly

Engineering Contradiction:
Improvespectral measurement capabilityVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the collimating optics and coded masks from the traditional hyperspectral imaging system, retaining only the essential dispersive element (prism) and image sensor. This extraction eliminates unnecessary components while preserving the core spectral measurement functionality through direct projection of dispersed light onto the sensor.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes the prism serve multiple functions: it acts as both the dispersive element for spectral separation and the projection element for image formation. By eliminating dedicated collimating optics, the prism's function is extended to handle both spectral dispersion and spatial mapping, reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If a large mask with many pinholes is used to isolate spectral dispersion, then spectral information is captured, but spatial resolution decreases significantly

Engineering Contradiction:
Improvespectral information captureVSAvoidspatial resolution
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent completely removes the large pinhole mask from the optical path, replacing it with a direct projection approach where dispersed light from the entire scene is mapped onto the image sensor. This eliminates the spatial resolution degradation caused by the mask while preserving spectral information through the prism's dispersion.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transitions from a mask-based spatial filtering approach to a direct optical projection approach, changing the dimensionality of information capture. Instead of sampling through discrete pinholes (spatial dimension), the system captures continuous spectral information across the entire spatial field through the prism's angular dispersion mapped to spectral bands.

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

3Productivity

If multiple optical elements (prism, mirror, lens array) are used for snapshot image mapping, then spectral imaging is achieved, but device complexity increases

Engineering Contradiction:
Improvesnapshot spectral imaging capabilityVSAvoidnumber of optical elements
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple optical elements into a single prism. The prism simultaneously performs spectral dispersion and spatial projection that would otherwise require separate mirrors, lens arrays, and other optical components. This consolidation achieves snapshot spectral imaging with minimal elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single prism in the patent performs multiple functions: it disperses light into spectral bands, projects the dispersed image onto the sensor, and enables snapshot capture without requiring separate optical paths for different spectral bands. This multi-functionality eliminates the need for mirrors, lens arrays, and other complex optical elements.

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

This approach enables portable, cost-effective hyperspectral imaging with high spectral resolution and minimal impact on spatial resolution, allowing general users to capture hyperspectral information without advanced skills or complex setups.

Implementation Method 1

a dispersion model for dispersion created by a prism

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

spectral dispersion by placing a large mask of pinholes in front of a prism

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentUS10891721B2Method for reconstructing hyperspectral image using prism and system therefor
Publication Date: 2021.01.12 KOREA ADVANCED INST OF SCI & TECH
  • US10891721B2 patent drawing
  • US10891721B2 patent drawing
  • US10891721B2 patent drawing

AI summary

A method for reconstructing a hyperspectral image and a system therefor are provided. The method includes obtaining a dispersion model for dispersion created by a prism included in a camera, the prism including no coded aperture, and reconstructing a hyperspectral image corresponding to a captured image based on the dispersion model.