Abstract: Anew high fidelity filtering algorithm(HFFA) using medians in moving window is proposed. In case the window width is set to include 2m +1 data points, peaks with widths greater than m points are reserved without distortion, while peaks with widths smaller than m points are completely removed. Compared with other conventional filtering methods, in particular the widely used ones based upon weighted sums, this algorithm has advantages of better filtering effect and less distortion. Ensuring peak height and peak position, which are two major parameters, to be least changed, this new algorithm is especially feasible for filtering physico-chemical spectrum from noises.

Key words: Instrument analysis, Data processing, Digital filtering