Filtering process illustrated for KIC 4357272. The top plot shows the amplitude spectrum before (in black) and after the high-pass filtering (in red). The signal below the cutoff-frequency of 1.5 d^-1 has been completely removed, while the signal at higher frequencies is retained, and now has a lower noise level. The middle plot shows the original light curve (black circles) with its low-frequency part superimposed (red curve, signal below 1.5 d^-1). The high-pass filtered version is then obtained by subtracting the red curve from the original light curve, as shown in the bottom plot. The eclipses are now clearly visible and easily detectable with automated methods.