deletions | additions       diff --git a/Introduction.md b/Introduction.md  index c267ec5..f1d993e 100644  --- a/Introduction.md  +++ b/Introduction.md 
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Numerous methods exist for analysing sparks in confocal linescans. These employ various different approaches: noise tresholding \cite{R_os_2001,Picht_2007}, wavelet transform \cite{Szab__2010}, etc.  Recently, a method was developed by Tian et al., \cite{Tian_2012}, where fluorescence time trace in each pixel is fitted and provides a practically noise free approximation of the original fluorescence data. This pixel-by-pixel method had, however, several limitations which made it impractical to be used  foruse with  Ca2+ release event detection. Here we extend the method by Tian et al., in several ways. The new method allows for Ca2+ release event classification based on pixel-by-pixel denoising of the original signal.