The present disclosure provides a method of standardizing a digital radiographic medical image, including obtaining a digital radiographic image of a variable attenuation plate to provide at least one reference value of at least one image characteristic, such as optical density and contrast, and standardizing the digital radiographic medical image against the reference values. Also provided are methods for comparing two or more radiographic images including standardizing the images against at least one reference value of at least one image characteristic obtained from a digital radiographic image of a variable attenuation plate.
