“…When the function f is globally Hölder continuous, it has been proved in [25,31] that the exponent h f (t) can always be obtained through the asymptotic behavior of the wavelet coefficients of f located in a neighborhood of t, when the wavelet is smooth enough. Then, wavelet expansions have been used successfully to characterize the iso-Hölder sets of wide classes of functions [26,27,11,29,30,3,9,17], sometimes directly constructed as wavelet series (expansions in Schauder's basis have also been used [32]). …”