A method and device for calculating a value representative of a signal at an interpolation time (SQTM), based on an input sequence (SQ1) representative of a temporal sampling of the signal. An adaptive up-sampling is performed by identifying a limited portion of the input sequence (SS), selected such as to temporally span the interpolation time (SQTM), thus allowing precise interpolation of input samples temporally local to the interpolation time (SQTM). The limited portion of the input sequence (SS), e.g. only one sample on each side of the interpolation time (SQTM), is then up-sampled to form an up- sampled sequence (SQ2), which has a rather low rate on average, due to the discarded input samples, e.g. equal to the sample rate of the input sequence (SQ1). However, locally around the interpolation time (SQTM), the sample rate is higher. Finally, it is possible to calculate a value representative of the signal at the interpolation time (V(TM)) in response to the up- sampled sequence (SQ2). Using linear FIR filters in the up-sampling process, a significant reduction of processing power can be saved, and still a high precision with a preserved phase information can be obtained, thus allowing the method to be used e.g. for optical shape sensing applications.Linvention porte sur un procédé et un dispositif pour calculer une valeur représentative dun signal à un instant dinterpolation (SQTM), sur la base dune séquence dentrée (SQ1) représentative dun échantillonnage temporel du signal. Un suréchantillonnage adaptatif est effectué par identification dune partie limitée de la séquence dentrée (SS), sélectionnée de manière à sétaler temporellement sur linstant dinterpolation (SQTM), permettant ainsi une interpolation précise déchantillons dentrée temporellement locaux à linstant dinterpolation (SQTM). La partie limitée de la séquence dentrée (SS), par exemple un seul échantillon de chaque côté de linstant dinterpolation (SQTM), est ensuite suréchantillonnée afin de former u
