Non-uniform Attenuation Pattern Modulator for Light Field Spatial Resolution
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Solution Overview
Problem
Conventional light field imaging systems face resolution deterioration due to the need to acquire angular data, resulting in lower spatial data resolution, and existing modulators assume uniform spatial and angular bandwidths, leading to inefficient frequency responses.
Innovation Solution
A modulator with a non-uniform attenuation pattern that generates frequency responses dependent on position, allowing for more spatial data in low angular frequencies and less in high angular frequencies, using a transparent layer with a metal layer to create grey-scale values by shielding units, and a data processor for Fourier transformations and zero-padding to restore high-resolution 4D light field data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If uniform sampling is applied to spatial data using existing modulators, then the system is simple to implement, but spatial resolution deteriorates due to equal bandwidth allocation across all frequency regions
Solution Approach 1:
The patent applies local quality by creating a non-uniform attenuation pattern where different regions of the modulator have different transmission characteristics. Specifically, the attenuation pattern is designed to provide higher spatial resolution in low angular frequency regions and lower resolution in high angular frequency regions, matching the natural distribution of spatial information in light field data. This resolves the contradiction by allowing high spatial resolution where needed without requiring uniformly high resolution across all regions, thereby reducing overall system complexity while maintaining manufacturing precision in critical areas.
2Loss of information
If 4D light field data is captured using conventional modulators, then angular data can be acquired, but spatial resolution is reduced to 1/144 of maximum resolution due to the need for angular sampling
Solution Approach 1:
The patent applies parameter changes by modifying the attenuation pattern parameter from uniform to non-uniform. The non-uniform attenuation pattern strategically allocates sampling density across different angular frequencies, capturing more spatial information in low-frequency regions where most spatial detail resides, while using coarser sampling in high-frequency regions. This parameter change enables the system to maintain angular data acquisition capability while significantly reducing spatial resolution loss, as the non-uniform sampling better matches the information distribution characteristics of light field data.
3Manufacturing precision
If existing modulators with uniform frequency responses are used, then the system design is straightforward, but frequency responses appear at uniform intervals which does not match the natural distribution of spatial data in the frequency domain
Solution Approach 1:
The patent applies asymmetry by designing an attenuation pattern that creates non-uniform frequency responses dependent on position. Instead of uniform intervals, the frequency responses are distributed asymmetrically to match the natural distribution of spatial data in the frequency domain. The asymmetric pattern concentrates sampling in low-angular-frequency regions where spatial information is most dense, while using sparser sampling in high-angular-frequency regions. This asymmetric design improves frequency response distribution accuracy while the systematic approach to creating the asymmetric pattern keeps fabrication complexity manageable.
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 enhances spatial resolution in low angular frequency regions while maintaining image quality, allowing for refocusing and high-resolution image creation from 4D light field data.
Implementation Method 1
a metal layer mounted on the transparent layer which forms the attenuation pattern and configured to attenuate light passing through the transparent layer to different degrees
Data Source
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AI summary
A technology of acquiring and processing light field data for images is provided. A light field data acquisition apparatus includes a modulator with an attenuation pattern to spatially modulate a 4D light field for an image, and a sensor to acquire 2D signals of the spatially modulated 4D light field. By utilizing the attenuation pattern of the modulator, more spatial data may be acquired in a low angular frequency region than that acquired in a high angular frequency region.