基于连续小波变换的FTIR光谱拟合算法

FTIR Spectral Fitting Algorithm Based on Continuous Wavelet Transform

提出了一种基于连续小波变换的FTIR光谱拟合算法。在计算差减尺度因子时,同时考虑原始谱图及其连续小波变换谱图,从光谱最小二乘拟合的角度求解,克服了常规差谱算法中的参考峰及差减因子的人工选择问题。采用六种不同的小波进行光谱拟合,用计算得到的差减因子来定量酒精度,误差绝对值的平均值仅为0.047°～0.072°,误差标准差仅为0.056°～0.091°。实验结果表明,连续小波变换结合最小二乘拟合的光谱拟合模型能为FTIR差谱提供一种准确可靠的新方法。

An FTIR spectrum fitting algorithm based on continuous wavelet transform is proposed.In calculating the factor of difference spectrum,the algorithm takes into account both the original spectrum and its continuous wavelet transformed spectra,which effectively overcomes the problem of reference peak selection and manual factor selection in most commercial software.The detailed discussions on wavelet scale,order and basis are included.The spectral fitting is performed on six wavelet basis functions and the obtained scale factor is used to quantify the content of liquor,and the corresponding mean absolute error ranges from 0.047 to 0.072,and the standard deviation ranges from 0.056 to 0.091.Experimental results show that the CWT combined with least squares fitting provides an accurate and reliable new method for FTIR spectral subtraction.