Spectral image processing method, computer-executable spectral image processing program, spectral imaging system

The present invention provides a spectral image processing method capable of reducing noise without damaging necessary information as much as possible. The spectral image processing method of the present invention is a spectral image processing method of performing processing on a spectral image of a specimen, including a step of normalizing spectra (= spectral brightness curves) of respective pixels constituting the spectral image such that their brightness levels become equal (S1), a step of smoothing the normalized spectra in spatial directions of the respective pixels (S2), and a step of denormalization of multiplying spectra of the respective pixels obtained by the smoothing by either one of brightness levels of the pixels corresponding the spectra and values corresponding to the brightness levels (S3). Consequently, the noise can be reduced while information on brightness distribution on the image is maintained.