On the Insensitivity of Bit Density to Read Noise in One-Bit Quanta Image Sensors
On the Insensitivity of Bit Density to Read Noise in One-Bit Quanta Image Sensors
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DOI：
10.1109/jsen.2023.3235493
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发表时间：
2022-03
影响因子：
4.3
通讯作者：
Stanley H. Chan
中科院分区：
文献类型：
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作者：
Stanley H. Chan
一位量子图像传感器 (QIS) 是一种光子计数设备，可产生二进制测量结果，其中每位代表光子的存在或不存在。传感器使用阈值 ${q}$ 将模拟电压量化为二进制位。比特流中 1 的平均数量称为比特密度，并且是信号估计的足够统计数据。当量子曝光为 1 并且阈值为 ${q} = {0.5}$ 时，会观察到一个有趣的现象。只要读取噪声水平不超过一定限度，位密度就表现出不敏感性。换句话说，位密度保持恒定，与读取噪声量无关。本文通过推导该现象发生的条件，对该现象提供了数学解释。人们发现，当底层泊松-高斯分布的某些形式的对称性成立时，不敏感性就成立。
The one-bit quanta image sensor (QIS) is a photon-counting device that produces binary measurements where each bit represents the presence or absence of a photon. The sensor quantizes the analog voltage into the binary bits using a threshold value ${q}$ . The average number of ones in the bitstream is known as the bit density and is the sufficient statistics for signal estimation. An intriguing phenomenon is observed when the quanta exposure is at the unity and the threshold is ${q} = {0.5}$ . The bit density demonstrates an insensitivity as long as the read noise level does not exceed a certain limit. In other words, the bit density stays at a constant independent of the amount of read noise. This article provides a mathematical explanation of the phenomenon by deriving conditions under which the phenomenon happens. It was found that the insensitivity holds when some forms of the symmetry of the underlying Poisson–Gaussian distribution hold.