Study on Color Information Degradation Induced by γ-ray Radiation in CMOS Cameras

Abstract

The γ-rays are widely and abundantly present in strong nuclear radiation environments, and when they act on the camera equipment used to obtain environmental visual information on nuclear robots, radiation effects will occur, which will degrade the performance of the camera system, reduce the imaging quality, and even cause catastrophic consequences. Color reducibility is an important index for evaluating the imaging quality of color camera, but its degradation mechanism in a nuclear radiation environment is still unclear. In this paper, the γ-ray irradiation experiments of CMOS cameras were carried out to analyse the degradation law of the camera’s color reducibility with cumulative irradiation and reveal the degradation mechanism of the color information of the CMOS camera under γ-ray irradiation. The results show that the spectral response of CMOS image sensor (CIS) and the spectral transmittance of lens after irradiation affect the values of a* and b* in the LAB color model. While the full well capacity (FWC) of CIS and transmittance of lens affect the value of L* in the LAB color model, thus increase color difference and reduce brightness, the combined effect of color difference and brightness degradation will reduce the color reducibility of CMOS cameras. Therefore, the degradation of the color information of the CMOS camera after γ-ray irradiation mainly comes from the changes in the FWC and spectral response of CIS, and the spectral transmittance of lens.

Keywords

• cmos camera
• color reducibility
• γ-ray
• nuclear radiation