Focal Tomography Volume Imaging with Cubic-Phase Modulation
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Solution Overview
Problem
Modern cameras struggle to capture high-resolution three-dimensional images in a single snapshot, as they typically require focusing on a single plane and degrade image quality from other ranges, with existing volume-imaging techniques trading off transverse or temporal resolution for improved longitudinal resolution.
Innovation Solution
The implementation of a volume imaging system using focal tomography with a collector lens, a three-dimensional reference structure that modulates the image field, and image estimation algorithms to produce high-resolution two-dimensional images at multiple focus ranges, enabling diffraction-limited resolution across a scene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If focal scanning is used to achieve volume imaging, then longitudinal resolution is improved, but frame acquisition rate is reduced due to sequential acquisition
Solution Approach 1:
The patent applies wavefront coding as a preliminary optical modulation that encodes depth information into the captured image, allowing all depth ranges to be captured simultaneously in a single snapshot rather than requiring sequential focal scanning. This preliminary encoding enables subsequent computational recovery of high-resolution images at multiple depths without sacrificing frame rate.
2Adaptability or versatility
If radiance sampling with microlens array is used, then volume imaging capability is achieved, but lateral image resolution is limited by aperture diameter of lenslets
Solution Approach 1:
The patent introduces a cubic-phase modulating element as an intermediary optical component that transforms the trade-off between volume imaging capability and lateral resolution. This modulating element encodes depth information in a way that allows both volume imaging and high lateral resolution to be achieved simultaneously through computational processing, rather than being limited by physical aperture constraints.
3Length of stationary object
If wavefront coding is applied to extend depth of field, then longitudinal range is improved, but transverse image resolution is degraded due to reduced modulation transfer function
Solution Approach 1:
The patent uses cubic-phase wavefront coding to transform the optical transfer function characteristics, changing the parameter space in which depth information is encoded. This parameter transformation allows the system to achieve extended depth of field while preserving transverse resolution through computational deconvolution, rather than suffering from reduced modulation transfer function at all focal ranges.
4Measurement precision
If conventional cameras focus on single plane, then transverse resolution at focal plane is maximized, but light from other ranges degrades the image rather than contributing useful data
Solution Approach 1:
The patent adds a depth dimension to the conventional two-dimensional imaging by applying cubic-phase wavefront coding. This transformation encodes information from multiple depth ranges into the captured image, allowing the system to recover useful image data from non-focal ranges through computational processing, rather than treating it as degrading out-of-focus light.
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 snapshot imaging of three-dimensional scenes with high image resolution, improving efficiency and maintaining transverse resolution without the need for sequential acquisition or reduced lateral image resolution.
Implementation Method 1
An imaging system includes a collector lens that forms an image field of the scene
Implementation Method 2
The reference structure comprises a volume distribution of nanoparticles that modulate the image field via optical scattering
Data Source
AI summary
A method and system for forming a three-dimensional image of a three-dimensional scene using a two-dimensional image sensor are disclosed. Formation of a three-dimensional image is enabled by locating a coded aperture in an image field provided by a collector lens, wherein the coded aperture modulates the image field to form a modulated image at the image sensor. The three-dimensional image is reconstructed by deconvolving the modulation code from the image data, thereby enabling high-resolution images to be formed at a plurality of focal ranges.