Zhang Zhaoning, Wang Yujie, Piestun Rafael, Huang Zhen-Li
Opt Express. 2021 Mar 1;29(5):6668-6690. doi: 10.1364/OE.418684.
With promising properties of fast imaging speed, large field-of-view, relative low cost and many others, back-illuminated sCMOS cameras have been receiving intensive attention for low light level imaging in the past several years. However, due to the pixel-to-pixel difference of camera noise (called noise non-uniformity) in sCMOS cameras, researchers may hesitate to use them in some application fields, and sometimes wonder whether they should optimize the noise non-uniformity of their sCMOS cameras before using them in a specific application scenario. In this paper, we systematically characterize the impact of different types of sCMOS noise on image quality and perform corrections to these types of sCMOS noise using three representative algorithms (PURE, NCS and MLE). We verify that it is possible to use appropriate correction methods to push the non-uniformity of major types of camera noise, including readout noise, offset, and photon response, to a satisfactory level for conventional microscopy and single molecule localization microscopy. We further find out that, after these corrections, global read noise becomes a major concern that limits the imaging performance of back-illuminated sCMOS cameras. We believe this study provides new insights into the understanding of camera noise in back-illuminated sCMOS cameras, and also provides useful information for future development of this promising camera technology.
背照式sCMOS相机具有成像速度快、视野大、成本相对较低等诸多优良特性，在过去几年中，一直备受关注，用于低光水平成像。然而，由于sCMOS相机中相机噪声的像素间差异（称为噪声不均匀性），研究人员在某些应用领域可能会犹豫是否使用它们，有时还会思考在特定应用场景中使用之前是否应该优化其sCMOS相机的噪声不均匀性。在本文中，我们系统地描述了不同类型的sCMOS噪声对图像质量的影响，并使用三种代表性算法（PURE、NCS和MLE）对这些类型的sCMOS噪声进行校正。我们验证了使用适当的校正方法，可以将包括读出噪声、偏移和光子响应在内的主要类型相机噪声的不均匀性推至常规显微镜和单分子定位显微镜可接受的水平。我们进一步发现，经过这些校正后，全局读出噪声成为限制背照式sCMOS相机成像性能的主要问题。我们相信这项研究为理解背照式sCMOS相机中的相机噪声提供了新的见解，也为这种有前景的相机技术的未来发展提供了有用的信息。
