Plenoptic Imaging System Research Articles

Development of a high-speed plenoptic imaging system and its application to marine biology PIV

Plenoptic particle image velocimetry (PPIV) has been demonstrated in the past as a viable single-/dual-camera technique for 3D flow measurements. Compared to established four-camera tomographic-PIV and 3D-PTV, PPIV has the advantages of lower cost, a simpler setup with a smaller footprint, a deeper depth-of-field for a given aperture and potential for access to otherwise optically restricted facilities. However, because camera bodies must be significantly modified to accommodate an embedded plenoptic microlens array (MLA), past PPIV implementations have been limited to <5 Hz low-speed Imperx cameras. The mitigation of this shortcoming through the development of a modular plenoptic adaptor is hereby presented. The developed adaptor, which consists of an externally mounted MLA and a pair of relay lenses, attaches to and enables plenoptic capability in unmodified off-the-shelf imaging devices, including kHz-rate high-speed cameras and intensifiers. Imaging performance is found to be comparable to embedded-MLA designs, and results from the PPIV measurement of 4D flows around a ctenophore Mnemiopsis (‘comb jelly’) using the high-speed system is hereby presented.

Plenoptic Face Presentation Attack Detection.

The vulnerability of current face recognition systems to presentation attacks significantly limits their application in biometrics. Herein, we present a passive presentation attack detection method based on a complete plenoptic imaging system which can derive the complete plenoptic function of light rays using a single detector. Moreover, we constructed a multi-dimensional face database with 50 subjects and seven different types of presentation attacks. We experimentally demonstrated that our approach outperforms the state-of-the-art methods on all types of presentation attacks.

Research on computationally adaptive plenoptic imaging

As for computational adaptive plenoptic imaging system, the light-field of the target and interference are measured together, and then according to distribution characteristics of the four-dimensional light-field information between the target and the disturbed factors, target and disturbed factors can be effectively separated. This technique can be used to detect and recover the wavefront distortion caused by interference in the large field of view, and adaptively compensate for complicated wavefront aberration by means of computation. Compared with the traditional adaptive optics imaging method, the proposed method has a larger detecting field of view, and can directly analyze and compute wavefront information based on the extended target.

A Comparison of Plenoptic Imaging System and Camera Array System

A Comparison of Plenoptic Imaging System and Camera Array System

A Comparison of Plenoptic Imaging System and Camera Array System

A Comparison of Plenoptic Imaging System and Camera Array System

Design of an open-ended plenoptic camera for three-dimensional imaging of dusty plasmas

Herein, the design of a plenoptic imaging system for three-dimensional reconstructions of dusty plasmas using an integral photography technique has been reported. This open-ended system is constructed with a multi-convex lens array and a typical reflex CMOS camera. We validated the design of the reconstruction system using known target particles. Additionally, the system has been applied to observations of fine particles floating in a horizontal, parallel-plate radio-frequency plasma. Furthermore, the system works well in the range of our dusty plasma experiment. We can identify the three-dimensional positions of dust particles from a single-exposure image obtained from one viewing port.

Experimental assessment of a 3-D plenoptic endoscopic imaging system.

An endoscopic imaging system using a plenoptic technique to reconstruct 3-D information is demonstrated and analyzed in this Letter. The proposed setup integrates a clinical surgical endoscope with a plenoptic camera to achieve a depth accuracy error of about 1 mm and a precision error of about 2 mm, within a 25 mm × 25 mm field of view, operating at 11 frames per second.

Calcium neuroimaging in behaving zebrafish larvae using a turn-key light field camera.

Reconstructing a three-dimensional scene from multiple simultaneously acquired perspectives (the light field) is an elegant scanless imaging concept that can exceed the temporal resolution of currently available scanning-based imaging methods for capturing fast cellular processes. We tested the performance of commercially available light field cameras on a fluorescent microscopy setup for monitoring calcium activity in the brain of awake and behaving reporter zebrafish larvae. The plenoptic imaging system could volumetrically resolve diverse neuronal response profiles throughout the zebrafish brain upon stimulation with an aversive odorant. Behavioral responses of the reporter fish could be captured simultaneously together with depth-resolved neuronal activity. Overall, our assessment showed that with some optimizations for fluorescence microscopy applications, commercial light field cameras have the potential of becoming an attractive alternative to custom-built systems to accelerate molecular imaging research on cellular dynamics.

Hemispherical Multiple Camera System for High Resolution Omni-Directional Light Field Imaging

Inspiration from light field imaging concepts has led to the construction of multi-aperture imaging systems. Using multiple cameras as individual apertures is a topic of high relevance in the light field imaging domain. The need for wide field-of-view (FOV) and high-resolution video for applications in areas of surveillance, robotics and automotive systems has driven the idea of omni-directional vision. Recently, the Panoptic camera concept has been presented that mimics the eyes of flying insects using multiple imagers. The Panoptic camera utilizes a novel methodology for constructing a spherically arranged wide FOV plenoptic imaging system whereas omni-directional image quality is limited by low resolution sensors. In this paper, a very-high resolution light field imaging and recording system inspired from the Panoptic approach is presented. Major challenges consisting of managing the huge amount of data as well as maintaining a scalable system are addressed. The proposed system is capable of recording omni-directional video at 30 fps with a resolution exceeding 9000 2400 pixels. The system is capable of capturing the surrounding light field in a FOV. This important feature opens the door to various post processing techniques such as quality-enhanced 3D cinematography, very high resolution depth map estimation and high dynamic-range applications which are beyond standard stitching and panorama generation.

Demonstration of a plenoptic microscope based on laser optical feedback imaging

A new kind of plenoptic imaging system based on Laser Optical Feedback Imaging (LOFI) is presented and is compared to another previously existing device based on microlens array. Improved photometric performances, resolution and depth of field are obtained at the price of a slow point by point scanning. Main properties of plenoptic microscopes such as numerical refocusing on any curved surface or aberrations compensation are both theoretically and experimentally demonstrated with a LOFI-based device.