When using plenoptic camera for digital refocusing, angular undersampling can cause severe (angular) aliasing artifacts. Previous approaches have focused on avoiding aliasing by pre-processing the acquired light field via prefiltering, demosaicing, reparameterization, and so on. In this paper, we present a different solution that first detects and then removes angular aliasing at the light field refocusing stage. Different from previous frequency domain aliasing analysis, we carry out a spatial domain analysis to reveal whether the angular aliasing would occur and uncover where in the image it would occur. The spatial analysis also facilitates easy separation of the aliasing versus non-aliasing regions and angular aliasing removal. Experiments on both synthetic scene and real light field data sets (camera array and Lytro camera) demonstrate that our approach has a number of advantages over the classical prefiltering and depth-dependent light field rendering techniques.
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http://dx.doi.org/10.1109/TIP.2017.2668613 | DOI Listing |
This study developed a detailed mathematical model to elucidate array slits imaging and linear CCD acquisition. Frequency domain analysis revealed the relationship between system parameters and spot image aliasing noise. Aliasing noise was reduced through optimized array slits design and linear CCD parameter selection, improving angular measurement resolution and stability.
View Article and Find Full Text PDFMicromachines (Basel)
September 2024
Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
High-precision, ultra-thin angular detectable imaging upon a single pixel holds significant promise for light-field detection and reconstruction, thereby catalyzing advancements in machine vision and interaction technology. Traditional light-direction angle sensors relying on optical components like gratings and lenses face inherent constraints from diffraction limits in achieving device miniaturization. Recently, angle sensors via coupled double nanowires have demonstrated prowess in attaining high-precision angle perception of incident light at sub-wavelength device scales, which may herald a novel design paradigm for ultra-compact angle sensors.
View Article and Find Full Text PDFIntegral imaging (InIm) working with a pixelated device (e.g., a display panel) and a microlens array (MLA) suffers from low spatial resolution because of a significant trade-off between the spatial and angular resolution.
View Article and Find Full Text PDFScience
October 2024
Department of Mathematics and Statistics, University of Exeter, Exeter, UK.
Magn Reson Imaging
July 2024
National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China. Electronic address:
Purpose: Multi-Shot (MS) Echo-Planar Imaging (EPI) may improve the in-plane resolution of multi-b-value DWI, yet it also considerably increases the scan time. Here we explored the combination of EPI with Keyhole (EPIK) and a calibrationless reconstruction algorithm for acceleration of multi-b-value MS-DWI.
Methods: We firstly analyzed the impact of nonuniform phase accrual in EPIK on the reconstructed image.
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