Patent ID: 8488983

Claim:
A method for processing a measurement signal to determine a toner quantity of a toner mark, comprising the steps of: generating the toner mark with aid of an image generation device; detecting the toner mark with aid of a measurement unit in that sample values determined by the measurement unit at sample points in time are output as said measurement signal for determining said toner quantity of said toner mark; and for determining said toner quantity determining a function to describe at least one part of a signal curve of the measurement signal on the basis of at least one part of the output sample values, and determining at least one extreme value of the function, and wherein the function is determined for a time period in which said extreme value is expected due to the toner mark supplied to the measurement unit, the time period being bounded by a measurement window in which said expected extreme value will lie within, and the function being determined on the basis of the sample values output by the measurement unit in the time period.