Abstract: The evaluated method for compressibility has been presented when the wavelet compression was applied to IRspectra. Using the method of controlling reconstructed RMSDwe can obtain the compression ratio under the condition of given reconstructed RMSD. With it, we can achieve the greater precision of which relative standard deviation is about eight percent and meet the need of estimating the error of reconstructed spectra and deciding the optimal parameter. In addition, for the different signals, the same wavelet function shows the different compressibilities. So we should select the spectra which are representative when evaluating the compressibility with the method of controlling RMSD.

Key words: IR spectra, Compression, Wavelet transform