Wavelet methods have become a widely spread tool in signal and image process- ing tasks. This book deals with statistical applications, especially wavelet based smoothing. The methods described in this text are examples of non-linear and non- parametric curve fitting. The book aims to contribute to the field both among statis- ticians and in the application oriented world (including but not limited to signals and images). Although it also contains extensive analyses of some existing methods, it has no intention whatsoever to be a complete overview of the field: the text would show too much...