Patent attributes
A method is described including receiving (S3) a first array of values obtained from measuring an array of touch panel sensor areas (FIG. 4; In,m). The method also includes generating (S4) a second array of values based on subtracting a reference array of values from the first array of values. The method also includes determining (S5) presence of at least one touch event in dependence upon the second array of value and, upon a negative determination (S8) generating a new reference array based on exponential smoothing of the reference array and the first array using a weighting factor, wherein the weighting factor is zero, and storing the new reference matrix and, upon a positive determination (S6) outputting the second array (FIG. 9).