Speaker: Mehdi Rezagholizadeh,
Ph.D. Candidate, Electrical and Computer Engineering,
Center for Intelligent Machines (CIM)
McGill University,
Title: Image Sensor Modeling: Color Measurement at Low Light Levels
(1) Time: Wednesday, Dec. 17th, 12:30-14:30 pm
(1) Location: faculty’s conference room, Isfahan University of Technology
(2) Local Organizer: IEEE Student Branch
(2) Time: Tuesday, Dec. 9th, 12:30-14:00pm
(2) Location: Room 212, School of Electrical and Computer Engineering of University of Tehran
Abstract and Presentation slides:
Investigating low light imaging is of high importance in the field of color science from different perspectives. One of the most important challenges arises at low light levels is the issue of noise, or more generally speaking, low signal to noise ratio. In the present work, effects of different image sensor noises such as: photon noise, dark current noise, read noise, and quantization error are investigated on low light color measurements. In this regard, a typical image sensor is modeled and employed for this study. A detailed model of noise is considered in the process of implementing the image sensor model to guarantee the precision of the results. Several experiments have been performed over the implemented framework and the results show that: first, photon noise, read noise, and quantization error lead to uncertain measurements distributed around the noise free measurements and these noisy samples form an elliptical shape in the chromaticity diagram; second, even for an ideal image sensor, in very dark situations, stable measuring of color is impossible due to the physical limitation imposed by the fluctuations in photon emission rate; third, dark current noise reveals dynamic effects on color measurements by shifting their chromaticities towards the chromaticity of the camera black point; fourth, dark current dominates the other sensor noise types in the image sensor in terms of affecting measurements. Moreover, an SNR sensitivity analysis against the noise parameters is presented over different light intensities.