Electroluminescence Imaging of PV devices: Determining the image quality

A no-reference method determining the image quality of electroluminescence (EL) images is presented. This allows mapping the estimated intensity based uncertainty originating from the EL image itself. Determining the uncertainty will allow for quantitative comparison and analysis of EL images and will define the minimum criteria of an imaging setup at given uncertainty values. This paper demonstrates and quantifies the decrease of uncertainty due to higher exposure times, better focusing and image enhancing methods. The uncertainty is calculated as combination of the signal-to-noise ratio, blur distortion and image manipulation ratio.