Demonstration of a multichannel, multiresolution imaging system

Belay, Gebirie Yizengaw; Ottevaere, Heidi; Meuret, Youri; Vervaeke, Michael; Erps, Jürgen Van; Thienpont, Hugo

doi:10.1364/ao.52.006081

Cited by 29 publications

(21 citation statements)

References 12 publications

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“…Previous strategies to achieve foveated sampling include: the use of non-uniform sensors (with variable photoreceptor density, mimicking the variable sampling rate of the retina) [1]; optical distortion for foveated lens design [2][3][4]; computational integration of independent imagers with dissimilar resolutions [5][6][7][8][9] and the use of a single sensor segmented into multiple channels with dissimilar magnifications [10]. The high cost of hardware and the added complexity of non-uniform sensors, or the optical complexity of foveal optics design, usually make these solutions unattractive.…”

Section: Introductionmentioning

confidence: 99%

“…An intermediate stage of this approach is to segment the detector into two or more channels of varying resolution [10]. This approach also enables arbitrary foveal ratios, however, if the width of the combined apertures fundamentally cannot exceed the sensor width, then the light-gathering and angular resolution will be limited (as sensor width then limits the f -number).…”

Section: Introductionmentioning

confidence: 99%

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Superimposed multi-resolution imaging

Carles

Babington²,

Wood³

et al. 2017

Opt. Express

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We present a novel approach to foveated imaging based on dual-aperture optics that superimpose two images on a single sensor, thus attaining a pronounced foveal function with reduced optical complexity. Each image captures the scene at a different magnification and therefore the system simultaneously captures a wide field of view and a high acuity at a central region. This approach enables arbitrary magnification ratios using a relatively simple system, which would be impossible using conventional optical design, and is of importance in applications where the cost per pixel is high. The acquired superimposed image can be processed to perform enhanced object tracking and recognition over a wider field of view and at an increased angular resolution for a given limited pixel count. Alternatively, image reconstruction can be used to separate the image components enabling the reconstruction of a foveated image for display. We demonstrate these concepts through ray-tracing simulation of practical optical systems with computational recovery.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Superimposed multi-resolution imaging

Carles

Babington²,

Wood³

et al. 2017

Opt. Express

View full text Add to dashboard Cite

show abstract

“…Higher foveal ratios are attractive for a wide range of applications [1][2][3][4][5][6], and previous approaches include the use of multiresolution systems using single [1] or multiple sensors [2][3][4] and applications in microscopy [5,6]. In this Letter we report an experimental demonstration of computational construction of a foveated image using a multicamera array.…”

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confidence: 92%

Multi-aperture foveated imaging

Carles

Chen

Bustin³

et al. 2016

Opt. Lett.

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Foveated imaging, such as that evolved by biological systems to provide high angular resolution with a reduced space-bandwidth product, also offers advantages for manmade task-specific imaging. Foveated imaging systems using exclusively optical distortion are complex, bulky, and high cost, however. We demonstrate foveated imaging using a planar array of identical cameras combined with a prism array and superresolution reconstruction of a mosaicked image with a foveal variation in angular resolution of 5.9:1 and a quadrupling of the field of view. The combination of low-cost, mass-produced cameras and optics with computational image recovery offers enhanced capability of achieving large foveal ratios from compact, low-cost imaging systems. Conventional approaches to imaging typically aim for an approximately uniform spatial sampling frequency across the field of view, but for many applications, such as targeting, the salient requirement is for high-resolution imaging within a central, so-called foveal region of the image combined with a lowresolution periphery providing situational awareness and context. Foveated imaging offers more efficient use of a limited number of detector pixels or can be implemented as an image processing technique applied to conventional images to improve the efficiency of information transmission. Here our emphasis is to attain a large ratio between the spatial sampling frequency and image acuity for the central field of view (FOV) and a reduced sampling frequency at larger field angles. This mimics biological systems, such as the human visual system, where foveated imaging is associated with a variation in photoreceptor packing density that approximately mirrors the angular variation in the optical resolution of the eye.Imaging systems with a variation in magnification of up to a factor of 2 between a central FOV and the periphery (the foveal ratio) have been demonstrated using conventional optical approaches, but higher ratios require dramatic increases in optical complexity. Higher foveal ratios are attractive for a wide range of applications [1][2][3][4][5][6], and previous approaches include the use of multiresolution systems using single [1] or multiple sensors [2][3][4] and applications in microscopy [5,6]. In this Letter we report an experimental demonstration of computational construction of a foveated image using a multicamera array. Two mechanisms contribute to the high foveal ratio of 5.9:1 between the angular sampling frequency in the foveal and peripheral regions of the image: image distortion introduced by an array of prisms located in front of the camera array introduces nonuniform angular sampling by the sensor, and overlap of the field of regard of the cameras at the central FOV enables digital superresolution to increase the angular sampling rate at foveal regions. The use of mass-produced cameras and simple prisms enables high-performance foveated imaging at minimal cost.A 5 × 5 multicamera array is assembled on a single printed circuit board, with the relatively low ...

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“…Once a design is optimized, the mastering and prototyping of the component can start. Thanks to our Deep Proton Writing [4] and Ultraprecision Diamond Tooling technologies, we can process optical components to feature extreme optical quality finish, high-aspect ratio structures and absolute freeform shapes [5,6]. Next to their obvious use non-imaging applications, we have recently shown that freeform optics also hold great potential for imaging applications [7,8].…”

Section: Introductionmentioning

confidence: 99%