基线校正是一种常用的消除光谱荧光干扰的方法,是拉曼光谱数据处理的必要步骤之一。传统的多项式拟合基线校正算法,简单且易于实现,但是拟合阶次难以确定,灵活性较差。使用非均匀B样条代替多项式进行拟合,在保留原有算法优点的基础上,利用原始拉曼谱图的峰位置信息自适应地确定非均匀B样条的节点向量,然后以固定阶次拟合光谱基线。B样条自身具有分段光滑的特性,而计算样条节点的节点向量自适应选取算法中的峰位置信息通过使用两次具有不同母函数的连续小波变换(continuous wavelet transform,CWT)来获取,既加强了原始光谱数据与B样条算法本身的联系,也克服了传统多项式拟合的不足。为了验证本文算法的有效性,选取了甲基对硫磷和某品牌菜籽油两种被测物进行实验,并使用该算法进行了基线校正,并与两种其他的基线校正算法与进行了对比。实验结果表明,该方法利用固定的拟合阶次就能达到较好的校正效果,所需要的参数较少,校正结果不会出现过拟合或欠拟合的现象,是一种有效的拉曼光谱基线校正算法。As one of the necessary steps for data processing of Raman spectroscopy,baseline correction is commonly used to eliminate the interference of fluorescence spectra.The traditional baseline correction algorithm based on polynomial fitting is simple and easy to implement,but its flexibility is poor due to the uncertain fitting order.In this paper,instead of using polynomial fitting,non-uniform B-spline is proposed to overcome the shortcomings of the traditional method.Based on the advantages of the traditional algorithm,the node vector of non-uniform B-spline is fixed adaptively using the peak position of the original Raman spectrum,and then the baseline is fitted with the fixed order.In order to verify this algorithm,the Raman spectra of parathion-methyl and colza oil are detected and their baselines are corrected using this algorithm,the result is made comparison with two other baseline correction algorithms.The experimental results show that the effect of baseline correction is improved by using this algorithm with a fixed fitting order and less parameters,and there is no over or under fitting phenomenon.Therefore,non-uniform B-spline is proved to be an effective baseline correction algorithm of Raman spectroscopy.国家重大科学仪器设备开发专项(2011YQ03012417)资
