He Song-hua, Chen Qiao, Duan Jiang
Guang Pu Xue Yu Guang Pu Fen Xi. 2015 Jun;35(6):1459-63.
The traditional spectral dimension reduction methods are usually carried out by matching the reconstructed spectra to the original spectra mathematically, which will often result in reconstructed spectra of small spectral reconstruction errors but very poor colorimetric accuracy when compared with the original one. In order to minimize both the spectral and colorimetric errors more efficiently, we proposed three spectral dimension reduction methods by introducing the characteristics of human vision. The first method is VPCA, in which we apply spectral luminous efficiency function to the original spectra before reduction; The Second method (LMSPCA) uses a matrix derived from LMS cone sensitivity to weight the original spectra before reduction, and the matrix can be form by two methods, in which the L, M, S cones response offset is calculated by in two different ways: one is computed as the absolute value of each corresponding wave length offset, and the other is calculated as the square of each corresponding wave length offset. The third method is LMSPCAs, which is based on the second method LMSPCA by further applying PCA to the residual spectra. The result shows that the VPCA method produces the poorest perfomance. The two cones response weighted matrixes of LMSPCA method have similar performances by presenting better colorimetric accuracy and low spectral accuracy, while LMSPCAs method which compensates for the spectral loss of LMSPCA method can produce higher spectral and colorimetric reconstruction accuracy and color stability under different light source, and satisfies the requirements of spectral color reproduction.
传统的光谱降维方法通常是通过将重建光谱与原始光谱进行数学匹配来实现的,与原始光谱相比,这种方法往往会得到光谱重建误差较小但比色精度很差的重建光谱。为了更有效地最小化光谱误差和比色误差,我们通过引入人类视觉的特性提出了三种光谱降维方法。第一种方法是VPCA,在降维之前,我们将光谱发光效率函数应用于原始光谱;第二种方法(LMSPCA)在降维之前使用从LMS视锥细胞敏感度导出的矩阵对原始光谱进行加权,该矩阵可以通过两种方法形成,其中L、M、S视锥细胞响应偏移通过两种不同方式计算:一种是计算为每个对应波长偏移的绝对值,另一种是计算为每个对应波长偏移的平方。第三种方法是LMSPCAs,它基于第二种方法LMSPCA,通过对残差光谱进一步应用主成分分析得到。结果表明,VPCA方法的性能最差。LMSPCA方法的两种视锥细胞响应加权矩阵具有相似的性能,比色精度较好但光谱精度较低,而LMSPCAs方法弥补了LMSPCA方法的光谱损失,在不同光源下能产生更高的光谱和比色重建精度以及颜色稳定性,满足光谱颜色再现的要求。