학술논문

Resolution Improvement In FZA Lens-Less Camera By Synthesizing Images Captured With Different Mask-Sensor Distances
Document Type
Conference
Source
2021 IEEE International Conference on Image Processing (ICIP) Image Processing (ICIP), 2021 IEEE International Conference on. :2808-2812 Sep, 2021
Subject
Computing and Processing
Signal Processing and Analysis
Optical diffraction
Diffraction
Optical distortion
Geometrical optics
Cameras
Optical imaging
Numerical models
Computational imaging
Lens-less camera
Image reconstruction
Wave optics
Super resolution
Language
ISSN
2381-8549
Abstract
Fresnel zone aperture (FZA) lens-less camera is a class of computational imaging systems that employs an FZA as a coded mask instead of an optical lens. FZA lens-less camera can perform fast deconvolution reconstruction and realize the re-focusing function. However, the reconstructed image’s spatial resolution is restricted by diffraction when using the conventional method derived from the geometrical optics model. In a previous study, we quantitatively analyzed the diffraction propagation between mask and sensor. Then we proposed a color-channel synthesis reconstruction method based on wave-optics theory. This study proposed a novel image reconstruction method without distorting the color information, comprehensively synthesizing two images captured with different mask-sensor distances to mitigate the diffraction influence and improve the image resolution. The numerical simulation and optical experiment results confirm that the proposed method can improve the spatial resolution to about two times that of the conventional method based on the geometrical optics model.