This paper addresses the scar tissue maturation process that occurs stepwise, and calls for reliable classification. The structure of collagen imaged by nonlinear optical microscopy (NLOM) in post-burn hypertrophic and mature scar, as well as in normal skin, appeared to distinguish these maturation steps. However, it was a discrimination analysis, demonstrated here, that automated and quantified the scar tissue maturation process. The achieved scar classification accuracy was as high as 96%. The combination of NLOM and discrimination analysis is believed to be instrumental in gaining insight into the scar formation, for express diagnosis of scar and surgery planning.