基于主成分分析的光谱重建训练样本选择方法研究

摘要

训练样本构成是影响光谱重建精度的一个重要因素，针对学习型光谱重建算法中训练样本选择问题，提出了一种基于主成分分析的训练样本选择方法。为了保证训练样本与重建样本的相似度，首先根据欧式距离最小原则从待选样本集中选择与重建样本相机响应值相似的样本，并去掉其中的重复样本；然后进行主成分分析；设定阈值筛选各主成分系数较大的样本作为训练样本，最后得到与主成分个数相同的训练样本子集。为验证该方法的有效性，通过在镜头前加载宽带滤色片搭建多通道图像获取系统采集多通道图像信息，将得到的各样本子集用作训练样本，利用伪逆法重建光谱信息，最后将重建的光谱精度与常用的训练样本及训练样本选择方法得到的重建光谱精度进行比较。实验结果表明：提出的方法显著提高了光谱重建的色度精度和光谱精度，优于常用的样本选择方法，能较大程度满足高精度颜色复制要求。%The composition of training samples set is an important influence factor of spectral reflectance reconstruction process. Representative color samples selection for learning-based spectral reflectance reconstruction is discussed in this paper.A method based on Principal Component Analysis (PCA)is proposed to perform sample selection.First of all,a part of samples are select-ed according to the minimum Euclidean distance criteria in terms of camera response value from a large number of samples,which aim to ensure the similarity between training samples and target samples.Then the PCA data processing method is applied to these samples after removing the duplicate samples.The samples with larger principal component loadings are regarded as the representative color samples.Different thresholds for each principal component are used to make decision whether the loading of sample is large enough.In order to validate the proposed method,the selected samples are used as training samples to recover the spectral reflectance of color patches.A real multi-channel imaging system by loading broadband color filters in front of lens is used in the experiment to acquire the multi-channel image dataset.In this paper the pseudo-inverse method is employed to recon-struct spectral reflectance of target color patches.It is shown that the proposed method is superior to the previous methods in spectral reconstruction accuracy and can meet the requirements of high precision color reproduction.