Department of Signal Processing, Tampere University of Technology, FI-33520 Tampere, Finland. eero.lihavainen@tut.fi|Department of Signal Processing, Tampere University of Technology, FI-33520 Tampere, Finland. eero.lihavainen@tut.fi|Department of Signal Processing, Tampere University of Technology, FI-33520 Tampere, Finland. eero.lihavainen@tut.fi|Department of Signal Processing, Tampere University of Technology, FI-33520 Tampere, Finland. eero.lihavainen@tut.fi