Coded apertures: past, present, and future application and design

Gottesman, Stephen R.

doi:10.1117/12.735494

Cited by 17 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where T is the coding matrix, which is circular with cell elements in rows [5]. In compressed sensing imaging systems without diffraction, the system response T is exactly the measurement matrix Φ.…”

Section: Theories About Coded Mask Imagingmentioning

confidence: 99%

“…Both the modification and estimation of PSF are based on the diffraction and interference of light propagation theories. Another different approach for image improvement with coded mask considers that if the diffraction effects are negligible, the scenes passing through the mask are pre-coded by the mask pattern [3][4][5]. That is the foundation of compressive sensing applications in optical imaging [6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

“…The ideas were based on characteristics of early coded aperture imaging (in heavy ray and visible light), like wide field of view (FOV) and large field of depth focus, to help improving the quality of infrared imaging. Gottesman proposed his design succeed with the conventional coded aperture in heavy ray imaging [5], which the detected images are geometric projections of the source point light pre-coded by the mask pattern. Therefore, the diffraction of infrared with longer wavelength was not considered in the initial design, but was included into his following works to estimate systems' imaging resolution [2,13,14].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A model of PSF estimation for coded mask infrared imaging

et al. 2014

View full text Add to dashboard Cite

The point spread function (PSF) of imaging system with coded mask is generally acquired by practical measurement with calibration light source. As the thermal radiation of coded masks are relatively severe than it is in visible imaging systems, which buries the modulation effects of the mask pattern, it is difficult to estimate and evaluate the performance of mask pattern from measured results. To tackle this problem, a model for infrared imaging systems with masks is presented in this paper. The model is composed with two functional components, the coded mask imaging with ideal focused lenses and the imperfection imaging with practical lenses. Ignoring the thermal radiation, the systems PSF can then be represented by a convolution of the diffraction pattern of mask with the PSF of practical lenses. To evaluate performances of different mask patterns, a set of criterion are designed according to different imaging and recovery methods. Furthermore, imaging results with inclined plane waves are analyzed to achieve the variation of PSF within the view field. The influence of mask cell size is also analyzed to control the diffraction pattern. Numerical results show that mask pattern for direct imaging systems should have more random structures, while more periodic structures are needed in system with image reconstruction. By adjusting the combination of random and periodic arrangement, desired diffraction pattern can be achieved.

show abstract

Section: Theories About Coded Mask Imagingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A model of PSF estimation for coded mask infrared imaging

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The 3×3 basic pattern is thus realized as 2×2 physical elements so that a pattern hole, for example, occupies 2×2 grid space measuring 2×3.2 = 6.4 mm by 2×3.2 = 6.4 mm area. This was done intentionally to keep the hole-to-thickness aspect ratio greater than unity to mitigate vignetting as discussed in reference [4]. For CACTIS the aspect ratio is 6.4 mm / 6 mm = 1.07.…”

Section: 1mentioning

confidence: 99%

Design of a coded aperture Compton telescope imaging system (CACTIS)

et al. 2010

Self Cite

View full text Add to dashboard Cite

We have developed a prototype of a scalable high-resolution direction and energy sensitive gamma-ray detection system that operates in both coded aperture (CA) and Compton scatter (CS) modes to obtain optimal efficiency and angular resolution over a wide energy range. The design consists of an active coded aperture constructed from 52 individual CZT planar detectors each measuring 3×3×6 mm 3 arranged in a MURA pattern on a 10×10 grid, with a monolithic 20×20×5 mm 3 pixelated (8×8) CZT array serving as the focal plane. The combined mode is achieved by using the aperture plane array for both Compton scattering of high-energy photons and as a coded mask for low-energy radiation. The prototype instrument was built using two RENA-3 test systems, one each for the aperture and the focal plane, stacked on top of each other at a distance of 130 mm. The test systems were modified to coordinate (synchronize) readout and provide coincidence information of events within a user-adjustable 40-1,280 ns window. The measured angular resolution of the device is <1 deg (17 mrad) in CA mode and is predicted to be approximately 3 deg (54 mrad) in CS mode. The energy resolution of the CZT detectors is approximately 5% FWHM at 120 keV. We will present details of the system design and initial results for the calibration and performance of the prototype.

show abstract

“…It uses coded aperture imaging (CAI) which has been widely used for imaging high-energy photons such as x-ray and gamma ray [2,3]. The major advantage of CAI over pinhole imaging is its large photon collection efficiency due to its large open area.…”

Section: Introductionmentioning

confidence: 99%

Depth estimation from multiple coded apertures for 3D interaction

2013

View full text Add to dashboard Cite

In this paper, we propose a novel depth estimation method from multiple coded apertures for 3D interaction. A flat panel display is transformed into lens-less multi-view cameras which consist of multiple coded apertures. The sensor panel behind the display captures the scene in front of the display through the imaging pattern of the modified uniformly redundant arrays (MURA) on the display panel. To estimate the depth of an object in the scene, we first generate a stack of synthetically refocused images at various distances by using the shifting and averaging approach for the captured coded images. And then, an initial depth map is obtained by applying a focus operator to a stack of the refocused images for each pixel. Finally, the depth is refined by fitting a parametric focus model to the response curves near the initial depth estimates. To demonstrate the effectiveness of the proposed algorithm, we construct an imaging system to capture the scene in front of the display. The system consists of a display screen and an x-ray detector without a scintillator layer so as to act as a visible sensor panel. Experimental results confirm that the proposed method accurately determines the depth of an object including a human hand in front of the display by capturing multiple MURA coded images, generating refocused images at different depth levels, and refining the initial depth estimates.

show abstract

Coded apertures: past, present, and future application and design

Cited by 17 publications

References 0 publications

A model of PSF estimation for coded mask infrared imaging

A model of PSF estimation for coded mask infrared imaging

Design of a coded aperture Compton telescope imaging system (CACTIS)

Depth estimation from multiple coded apertures for 3D interaction

Contact Info

Product

Resources

About