89 research outputs found
Resolution Limit of Correlation Plenoptic Imaging between Arbitrary Planes
Correlation plenoptic imaging (CPI) is an optical imaging technique based on intensity correlation measurement, which enables detecting, within fundamental physical limits, both the spatial distribution and the direction of light in a scene. This provides the possibility to perform tasks such as three-dimensional reconstruction and refocusing of different planes. Compared with standard plenoptic imaging devices, based on direct intensity measurement, CPI overcomes the problem of the strong trade-off between spatial and directional resolution. Here, we study the resolution limit in a recent development of the technique, called correlation plenoptic imaging between arbitrary planes (CPI-AP). The analysis, based on Gaussian test objects, highlights the main properties of the technique, as compared with standard imaging, and provides an analytical guideline to identify the limits at which an object can be considered resolved
Periodic patterns for resolution limit characterization of correlation plenoptic imaging
The measurement of the spatio-temporal correlations of light provides an
interesting tool to overcome the traditional limitations of standard imaging,
such as the strong trade-off between spatial resolution and depth of field. In
particular, using correlation plenoptic imaging, one can detect both the
spatial distribution and the direction of light in a scene, pushing both
resolution and depth of field to the fundamental limit imposed by wave-optics.
This allows one to perform refocusing of different axial planes and
three-dimensional reconstruction without any spatial scanning. In the present
work, we investigate the resolution limit in a particular correlation plenoptic
imaging scheme, by considering periodic test patterns, which provide, through
analytical results, a deeper insight in the resolution properties of this
second-order imaging technique, also in comparison with standard imaging.Comment: 16 pages, 4 figure
Correlated-photon imaging at 10 volumetric images per second
The correlation properties of light provide an outstanding tool to overcome
the limitations of traditional imaging techniques. A relevant case is
represented by correlation plenoptic imaging (CPI), a quantum-inspired
volumetric imaging protocol employing spatio-temporally correlated photons from
either entangled or chaotic sources to address the main limitations of
conventional light-field imaging, namely, the poor spatial resolution and the
reduced change of perspective for 3D imaging. However, the application
potential of high-resolution imaging modalities relying on photon correlations
is limited, in practice, by the need to collect a large number of frames. This
creates a gap, unacceptable for many relevant tasks, between the time
performance of correlated-light imaging and that of traditional imaging
methods. In this article, we address this issue by exploiting the photon number
correlations intrinsic in chaotic light, combined with a cutting-edge ultrafast
sensor made of a large array of single-photon avalanche diodes (SPADs). This
combination of source and sensor is embedded within a novel single-lens CPI
scheme enabling to acquire 10 volumetric images per second. Our results place
correlated-photon imaging at a competitive edge and prove its potential in
practical applications.Comment: 13 pages, 6 figure
Towards quantum 3d imaging devices
We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed
Paleobiology, Palaeopathology and Necrophobic Practices in Early Iron Age Burials (IX-VII Century BC) in Capo Colonna, Trani, Apulia, Southern Italy - The State of Health of a Small Sample from Iron Age
In this palaeobiological and palaeopathological study of skeletal remains, we attempt to define the physical characteristics,
living conditions and the state of health of a small sample from two early Iron Age (lX-VIII century BC) graves at
Capo Colonna, Trani (Bari, Apulia, southern Italy). In the thoraco-lumbar segment (Tll-L1) ofthe vertebral column of
an adult male 35years old, we found wedge-shaped deformation of the anterior part of T12 with kyphosis of the affected
tract. Digital radiography and volumetric reconstruction by 3D CT indicated that the alteration did not result from an
infectious process (Pott's disease). Instead, it was a traumatic lesion probably caused by falling from a height. The archaeological
investigation revealed extraordinary arrangements ofthe bodies in the graves: they were buried with a boulder
placed on the coffin. This practice has been seen in similar graves in the Balkan area, particularly in Greece, from the
Neolithic to the Early Middle Ages. The most likely explanation is a funeral ritual characterized by necrophobia, the purpose
of which was to prevent the deceased from returning to terrorize the living
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