The shine problem in hair: review of imaging methods and measures for luster.

There is a need for both a better understanding of the technical drivers of shiny appearance in hair and for standard methods and measures of shine. To this end, we develop standard treatment methods for changing hair shine and examine a number of image-based measurements of luster. Using psychophysical techniques to get a perceptual reference, we find that available technical measures are difficult to use when trying to quantify the small changes in shine associated with treatment.