Photovoltaic EL image preprocessing method and device and computer readable medium

The invention provides a photovoltaic EL image preprocessing method and device and a computer readable medium. The method comprises the following steps: acquiring a photovoltaic EL image to be processed; reducing the size of the photovoltaic EL image, and recording the reduced image as a first image; carrying out binarization processing on the first image by adopting a self-adaptive threshold value, classifying adjacent pixel points with the same value into the same connected region, and obtaining a plurality of connected regions; calculating the areas of the plurality of connected regions, and taking the connected region with the largest area as a target connected region; and calculating the position of a target connected region on the first image in the photovoltaic EL image, and cutting off a black invalid region in the photovoltaic EL image according to the position to obtain a second image. According to the invention, through adaptive threshold binarization processing and connected region processing, bla