[An auto-extraction method of spectral line for normal galaxy spectra]

Spectral line extraction for normal galaxy spectra is the most difficult task in spectral line auto-extraction of celestial spectra. The present paper presents a novel technique of spectral line auto-extraction for normal galaxy spectra. Firstly, the Max operator of two spectra is defined, and the operator produces a new spectrum whose intensity at each wavelength is the maximum of intensities of the two spectra; Secondly, the continuum is fitted in an iterative way, where in each iteration, the traditional wavelet method is performed for the spectrum obtained by the Max operation of the original spectrum, and the continuum is fitted in the last iteration; Finally, adaptive local thresholding associated with the universal thresholding is used to extract spectral lines. Experiments show that this method is superior to the traditional wavelet method. It will be helpful to the spectral line based automated spectral classification and parameter measurement.