The preset application provides a method by which a license plate character extraction device extracts characters from a vehicle license plate. The method may comprise the steps of: converting, into a gray tone image, a pre-inputted image acquired by capturing a license plate of a vehicle; comparing the color value of a pixel included in the grey tone image to a first average of color values of pixels in the vicinity of the pixel, so as to generate a converted image; comparing the converted image to a binarized image obtained by binarizing the converted image, so as to generate a refined image; and extracting characters included in the refined image.