The most known impact of charge lag in image sensors is the phenomenon of "ghost images" which refer to the residual images created as a result of the trapped charge as the scene transitions from bright to dark. These "ghost" artifacts are particularly problematic for video imaging and, therefore, traditional lag characterization has focused on quantifying inter-frame charge smear. In still imaging, however, the impact of lag on image quality has not been thoroughly characterized. This work studies the effect of lag that is caused by photodiode-barrier on image quality in still imaging with CMOS image sensors. It shows a direct correlation between lag and fixed-pattern noise, demonstrates color artifacts that are caused by lag, and explains the mechanism that results in appearance of these artifacts.
Leo Anzagira, Orit Skorka, Pulla Reddy Ailuri, Radu Ispasoiu, "Lag-Induced Image Artifacts in Still Imaging with CIS" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Image Sensors and Imaging Systems, 2018, pp 457-1 - 457-8, https://doi.org/10.2352/ISSN.2470-1173.2018.11.IMSE-457