Paper Info
Title
What Does a One-Bit Quanta Image Sensor Offer?
Abstract
The one-bit quanta image sensor (QIS) is a photon-counting device that captures image intensities using binary bits. Assuming that the analog voltage generated at the floating diffusion of the photodiode follows a Poisson-Gaussian distribution, the sensor produces either a “1” if the voltage is above a certain threshold or “0” if it is below the threshold. The concept of this binary sensor has been proposed for more than a decade and physical devices have been built to realize the concept. However, what benefits does a one-bit QIS offer compared to a conventional multi-bit CMOS image sensor? Besides the known empirical results, are there theoretical proofs to support these findings? The goal of this paper is to provide new theoretical support from a signal processing perspective. In particular, it is theoretically found that the sensor can offer three benefits: (1) Low-light: One-bit QIS performs better at low-light because it has a low read noise and its one-bit quantization can produce an error-free measurement. However, this requires the exposure time to be appropriately configured. (2) Frame rate: One-bit sensors can operate at a much higher speed because a response is generated as soon as a photon is detected. However, in the presence of read noise, there exists an optimal frame rate beyond which the performance will degrade. A Closed-form expression of the optimal frame rate is derived. (3) Dynamic range: One-bit QIS offers a higher dynamic range. The benefit is brought by two complementary characteristics of the sensor: nonlinearity and exposure bracketing. The decoupling of the two factors is theoretically proved, and closed-form expressions are derived.
Year
DOI
Venue
2022
10.1109/TCI.2022.3202012
IEEE Transactions on Computational Imaging
Keywords
DocType
Volume
Quanta image sensor (QIS),single-photon image sensor,bit-density,read noise,quanta exposure,statistical estimation,signal processing
Journal
8
ISSN
Citations 
PageRank 
2573-0436
0
0.34
References 
Authors
17
1
Name
Order
Citations
PageRank
Stanley H. Chan140330.95