In this study, three different materials (pure tungsten and two tungsten alloys with Fe and Ni dopants), which have been irradiated with a high-temperature deuterium plasma of 20, 25 and 100 plasma shots, are considered. The multifractal characteristics obtained from SEM images are then compared for the same specimens by analysing the distribution of defects and non-defects (nondamaged areas). A valid tendency was found that the brighter the original input image, the more accurate the results obtained when examining a non-damaged surface using multifractal characteristics.