An Approach to Improve the Signal-to-Noise Ratio of Active Pixel Sensor for Low-Light-Level Applications

2006 ◽  
Vol 53 (9) ◽  
pp. 2384-2391 ◽  
Author(s):  
N. Faramarzpour ◽  
M.J. Deen ◽  
S. Shirani
Keyword(s):  
Signal To Noise Ratio ◽  
Light Level ◽  
Signal To Noise ◽  
Low Light ◽  
Active Pixel Sensor ◽  
Active Pixel ◽  
Noise Ratio

scholarly journals The Signal to Noise Ratio in Speckle Interferometry

1979 ◽  
Vol 50 ◽  
pp. 23-1-23-18 ◽  
Author(s):  
J.C. Dainty ◽  
A.H. Greenaway
Keyword(s):  
Power Spectrum ◽  
Signal To Noise Ratio ◽  
Binary Star ◽  
Image Plane ◽  
Light Level ◽  
Speckle Interferometry ◽  
Signal To Noise ◽  
Speckle Image ◽  
Auto Correlation Function ◽  
Noise Ratio

AbstractRecent theoretical studies of the signal to noise ratio (SNR) of photon limited speckle (image plane) interferometry are reviewed. The SNR of an estimate of the object power spectrum is evaluated for both the single and double aperture cases, for arbitrary light levels. The SNR for the auto-correlation function method of analysis is also given for the low light level case and applied to the special case of binary star observations. The SNRs for the power spectrum and autocorrelation function analyses are compared and a comparison is also made between speckle (image plane) and amplitude (pupil or aperture plane) interferometry. Limiting observable magnitudes are estimated for some relevant cases.

scholarly journals The Optimal Synapse for Sparse, Binary Signals in the Rod Pathway

2006 ◽  
Vol 18 (1) ◽  
pp. 26-44 ◽  
Author(s):  
Paul T. Clark ◽  
Mark C. W. van Rossum
Keyword(s):  
Transfer Function ◽  
Signal To Noise Ratio ◽  
Bipolar Cells ◽  
Signal To Noise ◽  
Low Light ◽  
Rod Photoreceptors ◽  
Light Levels ◽  
Noise Ratio ◽  
Simulated Images ◽  
Rod Bipolar Cells

The sparsity of photons at very low light levels necessitates a nonlinear synaptic transfer function between the rod photoreceptors and the rod-bipolar cells. We examine different ways to characterize the performance of the pathway: the error rate, two variants of the mutual information, and the signal-to-noise ratio. Simulation of the pathway shows that these approaches yield substantially different performance at very low light levels and that maximizing the signal-to-noise ratio yields the best performance when judged from simulated images. The results are compared to recent data.

scholarly journals Physical noise propagation in color image construction: a geometrical interpretation

2019 ◽  
Vol 2019 (1) ◽  
pp. 375-380
Author(s):  
Axel Clouet ◽  
Jérôme Vaillant ◽  
David Alleysson
Keyword(s):  
Near Infrared ◽  
Color Image ◽  
Signal To Noise Ratio ◽  
Point Of View ◽  
Signal To Noise ◽  
Low Light ◽  
Image Construction ◽  
Color Sensor ◽  
Light Sensor ◽  
Noise Ratio

To avoid false colors, classical color sensors cut infrared wavelengths for which silicon is sensitive (with the use of an infrared cutoff filter called IR-cut). However, in low light situation, noise can alter images. To increase the amount of photons received by the sensor, in other words, the sensor's sensitivity, it has been proposed to remove the IR-cut for low light applications. In this paper, we analyze if this methodology is beneficial from a signal to noise ratio point of view when the wanted result is a color image. For this aim we recall the formalism behind physical raw image acquisition and color reconstruction. A comparative study is carried out between one classical color sensor and one specific color sensor designed for low light conditions. Simulated results have been computed for both sensors under same exposure settings and show that raw signal to noise ratio is better for the low light sensor. However, its reconstructed color image appears more noisy. Our formalism illustrates geometrically the reasons of this degradation in the case of the low light sensor. It is due on one hand to the higher correlation between spectral channels and on the other hand to the near infrared part of the signal in the raw data which is not intrinsically useful for color.

scholarly journals A SEC Vidicon System for Satellite Applications

1971 ◽  
Vol 41 ◽  
pp. 360-360
Author(s):  
G. E. Brückner
Keyword(s):  
Signal To Noise Ratio ◽  
Light Level ◽  
Zero Order ◽  
Signal To Noise ◽  
Compression Scheme ◽  
Low Light ◽  
Low Contrast ◽  
Satellite Applications ◽  
Theoretical Considerations

This paper describes a small, low power SEC vidicon camera developed for recording images of the outer solar corona from an OSO satellite. The SEC vidicon has been selected for this application because of its capability to integrate and store low light level and low contrast images. The achieved signal to noise ratio will be discussed and compared with theoretical considerations. A new operational method to readout the tube very slowly will be described. The influence of a zero order data compression scheme on the quality of the coronal images will be discussed.

LIGHT ADAPTATION AND RELIABILITY IN BLOWFLY PHOTORECEPTORS

1996 ◽  
Vol 07 (04) ◽  
pp. 437-444 ◽  
Author(s):  
R.R. DE RUYTER VAN STEVENINCK ◽  
S.B. LAUGHLIN
Keyword(s):  
Light Adaptation ◽  
Signal To Noise Ratio ◽  
Transduction Efficiency ◽  
Statistical Efficiency ◽  
Signal To Noise ◽  
Low Light ◽  
Frequency Dependent ◽  
Light Levels ◽  
Light Intensities ◽  
Noise Ratio

We characterize the reliability of response of blowfly photoreceptors at different light levels. These cells convey their information by graded potentials. Their reliability is quantified by the frequency-dependent contrast-normalized signal to noise ratio. Independently we estimate the effective photoconversion rate of the cells by counting individual photoconversion events, or quantum bumps, at calibrated low light levels. Comparing both results we quantify the statistical efficiency of photoconversion at higher light intensities, characterizing the transduction efficiency as a function of frequency. The light intensities used in these experiments ranged from about 300 to about 5×105 photoconversions per second per photoreceptor. Over most of this range, statistical efficiencies are within 50% at frequencies up to about 100 Hz.

Sign in / Sign up

Export Citation Format

Share Document