  Given a pattern x of length m and a text y of length n, both over an ordered
alphabet, the order-preserving pattern matching problem consists in finding all
substrings of the text with the same relative order as the pattern. It is an
approximate variant of the well known exact pattern matching problem which has
gained attention in recent years. This interesting problem finds applications
in a lot of fields as time series analysis, like share prices on stock markets,
weather data analysis or to musical melody matching. In this paper we present
two new filtering approaches which turn out to be much more effective in
practice than the previously presented methods. From our experimental results
it turns out that our proposed solutions are up to 2 times faster than the
previous solutions reducing the number of false positives up to 99%
