Friday, July 30, 2021

A Positive Effect of Image Sensor Noise

There is one positive consequence of image sensor noise - it helps to prevent forgeries. Université Paris-Saclay, France, and Universidad de la República, Uruguay, publish a paper "Noisesniffer: a Fully Automatic Image Forgery Detector Based on Noise Analysis" by Marina Gardella, Pablo Musé, Jean-Michel Morel, and Miguel Colom.

"Images undergo a complex processing chain from the moment light reaches the camera’s sensor until the final digital image is delivered. Each of these operations leave traces on the noise model which enable forgery detection through noise analysis. In this article we define a background stochastic model which makes it possible to detect local noise anomalies characterized by their number of false alarms. The proposed method is both automatic and blind, allowing quantitative and subjectivity-free detections. Results show that the proposed method outperforms the state of the art."

Quantum Dots Thesis

Universidad de Sevilla, Spain, publishes a BSc Thesis "Quantum dots: concept and application for image sensors" by Adri´an Romero Campelo.

"In the first part of this work (Chapter 2), a general outline of what quantum dots are and how they are manufactured (materials, techniques employed) will be provided. Besides, a complete description of the band structure of quantum dots, with an emphasis on their optoelectronic features, will be given too. In the second part of the thesis (Chapter 3), photodetection technologies are covered. After an introduction to the state of art of image sensors, the latest advances in quantum dot photodetection will be presented, considering their figures of merit and possible adaptation to current available production methods."

Another interesting recent thesis is from CEA-Leti and devoted to the modern microlens fabrication techniques, in French: "Étude d’une méthode de microfabrication 3D pour des applications de microlentilles d’imageurs" by Pierre Chevalier.

Thursday, July 29, 2021

Samsung Paper on Under-Display Camera

EI publishes Samsung paper "Under Display Camera Image Recovery through Diffraction Compensation" by Jeongguk Lee, Yunseok Choi, Han-Sol Lee, Eundoo Heo, Dongpan Lim, Geunyoung Lee, and Seongwook Song presented at EI conference in January 2021.

"Under Display Camera(UDC) technology is being developed to eliminate camera holes and place cameras behind display panels according to full display trend in mobile phone. However, these camera systems cause attenuation and diffraction as light passes through the panel, which is inevitable to deteriorate the camera image. In particular, the deterioration of image quality due to diffraction and flares is serious, in this regard, this paper discusses techniques for restoring it. The diffraction compensation algorithm in this paper is aimed at real-time processing through HW implementation in the sensor for preview and video mode, and we've been able to use effective techniques to reduce computation by about 40 percent."

IDTechEx Forecasts Event-Based Sensor Sales of $20M in 10 Years from Now

PRNewswire: IDTechEx analyst Matt Dyson says: "IDTechEx forecast the market for the event-based vision sensor chips alone rising from its primarily pre-revenue status today to $20 million per year over the next 10 years. Furthermore, much of the value is likely to be captured by the software facilitated by event-based vision hardware, leading to a much greater total market."

Regarding the potential markets and applications, IDTechEx thinks: "Event-based vision is highly relevant to recording rapidly changing situations that require immediate data processing (since the volume of data produced is much less). Applications that require high temporal resolution or high dynamic range are especially relevant.

IDTechEx, therefore, perceives the most promising applications as collision avoidance and navigation for autonomous vehicles/ADAS and unmanned aerial vehicles (drones). These markets have huge potential but will require substantial software development and data collection to fully interpret the event-based vision data. As such, IDTechEx believes that smaller markets with much more predictable input data, such as iris-tracking for AR/VR goggles and laser beam profiling, will see the earliest adoption of event-based vision."

Wednesday, July 28, 2021

Ams Releases NanEyeM Module

ams OSRAM has first announced NanEyeM camera module for single-use medical endoscopy almost 3 years ago. Over the past time, the company "made a few packaging changes to the module for improved robustness." Now ams fully releases NanEyeM to production. The small dimensions of 1.0 mm x 1.0 mm x 2.7 mm allow the module to be used in the smallest of areas.

Thanks to its space-saving size, the NanEyeM is made for use in areas of severe size restrictions, which includes single-use applications in bronchoscopy, urological endoscopy or endoscopic procedures in the kidney,” says Dina Aguiar, Marketing Manager at ams OSRAM. “The combination with the requisite high image quality makes the camera module a unique and attractive solution for the fast growing disposable endoscope market.

The module uses a so-called "chip on tip" approach. Here, the image sensor and the optics are placed at the tip of the device (distal end). This results in significantly better image quality than when the camera module is located at the other, proximal end. The NanEyeM offers a fully integrated imaging module with a wafer level multi-element optics. It was specifically designed for optimal performance at close range distances. The lens combines a wide FoV with an extended depth of field (EDOF), reducing distortions and delivering a sharp and accurate image. The camera has LVDS interface to transmit over long lengths of cable without loss of signal integrity. NanEyeM boasts a frame rate of up to 49 fps, while maintaining low power consumption. 

NanEyeM is the second generation of the NanEye2D from ams OSRAM. The camera module has been released to production and is available for ordering.

3D-Stacked SPAD Image Sensor

University of Edinburgh, University of Glasgow, and Heriot-Watt University publish a SPIE paper "High-speed vision with a 3D-stacked SPAD image sensor" by Istvan Gyongy, Germán Mora Martín, Alex Turpin, Alice Ruget, Abderrahim Halimi, Robert Henderson, and Jonathan Leach.

"We here consider an advanced direct ToF SPAD imager with a 3D-stacked structure, integrating significant photon processing. The device generates photon timing histograms in-pixel, resulting in a maximum throughput of 100's of giga photons per second. This advance enables 3D frames to be captured at rates in excess of 1000 frames per second, even under high ambient light levels. By exploiting the re-configurable nature of the sensor, higher resolution intensity (photon counting) data may be obtained in alternate frames, and depth upscaled accordingly. We present a compact SPAD camera based on the sensor, enabling high-speed object detection and classification in both indoor and outdoor environments. The results suggest a significant potential in applications requiring fast situational awareness."

Tuesday, July 27, 2021

ON Semi Announces 16MP Global Shutter Sensor for Machine Vision Applications

BusinessWire: ON Semiconductor expands its XGS series of CMOS sensors. The XGS 16000 is a 16MP global shutter sensor for factory automation applications including robotics and inspection systems. Consuming 1W at 65fps, the XGS 16000 is said to be one of the best in class for power consumption, among 29 x 29 mm sensors.

The XGS 16000 shares a common architecture and footprint with other XGS CMOS image sensors. This enables manufacturers to use a single camera design to develop products in different resolutions. 

The XGS 16000 is designed in a unique 1:1 square aspect ratio, which helps maximize the image capture area within the optical circle of the camera lens and ensure optimal light sensitivity. 

ON Semi offers color and mono versions of the XGS 16000 X-Cube and X-Celerator developer kits.

Sharp Image Sensor Lineup

2021 Sharp catalog reveals that its image sensor linup is still dominated by CCDs, although CMOS sensors section is expanding. Sharp CCDs are quite fast by CCD standards with 8MP one reaching 25fps frame rate:

Monday, July 26, 2021

e2v iToF Sensor Demos

Teledyne e2v publishes 3 video demos of its iToF Hydra3D sensor announced a year ago (1, 2, 3):

Photomultiplication in NIR Organic Diodes

Nature publishes a paper "Enhancing sub-bandgap external quantum efficiency by photomultiplication for narrowband organic near-infrared photodetectors" by Jonas Kublitski, Axel Fischer, Shen Xing, Lukasz Baisinger, Eva Bittrich, Donato Spoltore, Johannes Benduhn, Koen Vandewal, and Karl Leo from Technische Universität Dresden (Germany), Leibniz-Institut für Polymerforschung Dresden (Germany) and Hasselt University (Belgium).

"Photomultiplication-type organic photodetectors have been shown to achieve high quantum efficiencies mainly in the visible range. Much less research has been focused on realizing near-infrared narrowband devices. Here, we demonstrate fully vacuum-processed narrow- and broadband photomultiplication-type organic photodetectors. Devices are based on enhanced hole injection leading to a maximum external quantum efficiency of almost 2000% at −10 V for the broadband device. The photomultiplicative effect is also observed in the charge-transfer state absorption region. By making use of an optical cavity device architecture, we enhance the charge-transfer response and demonstrate a wavelength tunable narrowband photomultiplication-type organic photodetector with external quantum efficiencies superior to those of pin-devices. The presented concept can further improve the performance of photodetectors based on the absorption of charge-transfer states, which were so far limited by the low external quantum efficiency provided by these devices."