1. A method ( 200 ) for unified visual measurement of blur and noise distortions in digital image data, comprising: receiving ( 212 ) digital image data; simulating ( 214 ) a single-ended visual discrimination model (VDM); analyzing ( 216 ) individual just noticeable difference (JND) channels, including the responses of the highest spatial frequency channel(s); and selecting ( 218 ) a reference JND level corresponding to low noise and blur distortions.