@TECHREPORT{VarPaaKam:2006, author = {J. Vartiainen and P. Paalanen and J.-K. Kamarainen and L. Lensu and H. K\"alvi\"ainen}, title = {Minimum error contrast enhancement}, institution = {Department of Information Technology, Lappeenranta University of Technology}, year = {2006}, number = {102} }