全参考图像质量评价Theabove(ssim_index.m)isasinglescaleversionoftheSSIMindexingmeasure,whichismosteffectiveifusedattheappropriatescale.Theprecisely“right”scaledependsonboththeimageresolutionandtheviewingdistanceandisusuallydifficulttobeobtained.Inpractice,wesuggesttousethefollowingempir