It is assumed that each intensity curves is an inverted U shape, with an ascending phase, a plateau (at max intensity), and a decreasing phase. But it can happen that users mis-click and hence get odd values, generating multi-peaks with local optima or minima. These local optima/minima are removed by the correction option.

 

The standardization option however aims in “modifying” the individual curves so that they follow the same pattern: similar increasing phase duration, similar plateau duration, similar decreasing phase duration. The procedure used for this is the one proposed by Liu & McFie: