@misc{10481/86738,
year = {2019},
month = {6},
url = {https://hdl.handle.net/10481/86738},
abstract = {Hyperspectral imaging of effect coated samples can be challenging, mainly because of the large differences
in irradiance that stem from the orientation distribution of the metallic flakes contained in the
coating, and from the lightness variations from one sample to another. Besides, high spatial resolution
is needed to sample the details of the texture (sparkle) typical of these samples. In addition, focus search
strategy and image registration are essential to achieve high quality data for further analysis. In this work,
we propose and fully validate a capture framework for measuring spectral reflectance of effect-coated
samples with high spatial resolution in 45/0 geometry, using an LCTF (Liquid Crystal Tunable Filter) coupled
with a monochrome camera. The main features of the proposed framework are an optimized focus
search method based on object movement, a very precise alignment for the images captured in different
bands (image registration), achieving sub-pixel accuracy, and a dynamic procedure that uses several
white reference surfaces in exposure time estimation to cope with very dark or highly reflective samples.
The proposed capture device produces spectral reflectance values comparable to a conventional spectroradiometer
using the same observation/illumination geometry, with the additional advantage of achieving
a spatial resolution more than two times higher than the human visual system.},
organization = {Spanish State Agency of
Research (AEI) and the Ministry for Economy, Industry and Competitiveness
(MIMECO) by means of the grant number FIS2017-
89258-P with European Union FEDER (European Regional Development
Funds) support},
publisher = {Elsevier},
keywords = {Spectral imaging},
keywords = {Effect coatings},
keywords = {High resolution},
title = {Framework proposal for high-resolution spectral image acquisition of effect-coatings},
doi = {https://doi.org/10.1016/j.measurement.2019.05.024},
author = {Valero Benito, Eva María and Martínez Domingo, Miguel Ángel and Kirchner, Eric and van der Lans, Ivo and García Fernández, María and Eckhard, Timo Micha and Huertas Roa, Rafael},
}