Correcting cross-media instrument metamerism for reflectance estimation in multispectral imaging

Abstract

In multispectral imaging, the color accuracy of spectral reflectance estimation degrades significantly if the medium of test samples is different from that of calibration samples. This occurs mainly for two reasons, i.e., the different characteristics of spectral reflectances and the different measurement principles between an imaging system and a spectrophotometer. In this paper, this problem is referred to as cross-media instrument metamerism. We propose to correct it by using calibration samples from a standard color chart and a limited number of tuning samples with a target medium as a priori knowledge. The reflectance transform is computed by using both calibration and tuning samples, and the metamerism transform is calculated by modeling the correlation of camera responses between neighboring imaging channels. Experimental results show that the proposed method produces satisfactory spectral and colorimetric accuracy in reflectance estimation. The method could be deployed in practical applications when the available samples of certain media are inadequate for accurate reflectance estimation in a multispectral imaging system.

Adaptive characterization method for desktop color printers

“…The spectral images of textile fabrics were acquired using the multispectral imaging system developed in our laboratory. 3 …”

“…Multispectral imaging, for its ability in accurate reconstruction of spectral spectrum, has been extensively studied in recent years. [1][2][3] With the acquired reflectance spectrum, the colors of the object surfaces can be reproduced with high fidelity on output devices, provided that the devices are properly characterized. For a color printer, which is a typical output device, the characterization consists of forward and inverse models.…”

Artificial spectral vision for studying the spectral, the spatial and the temporal characteristics of dynamic optical phenomena in biomedicine

“…All images were captured with the same HSI camera system as described above. Acquiring both spectral and colorimetric values using the same device is essential for eliminating possible cross-media metamerism [10], which could effectively reduce the efficiency of the spectral estimation algorithms as well as the comparison between them. The Goodness-of-Fit [11] (GoF) with a threshold GoF>0.98 was adopted for assessing the spectral estimation accuracy of all the aforementioned algorithms and with each one using the experimental data and training target as they were described in the previous paragraphs.…”

Lighting Deviation Correction for Integrating-Sphere Multispectral Imaging Systems

“…The integrating sphere multispectral imaging system can measure reflectance at the spatial resolution of camera pixels, but will suffer more from the variation of reflection characteristics in a sample. The influence of the material and texture structure on reflectance measurement was also investigated in previous works [24,25].…”