Interim connection space based on colorimetric values for spectral image compression and reproduction

Abstract

A new interim and connection space (ICS) and its reconstruction method are proposed. The proposed ICS,tD65A, consists of six colorimetric values or two sets of tristimulus values under CIE illuminant D65 and A respectively. In addition, a new spectral decomposition based on the tD65A ICS and the Wiener Estimation matrix M W was introduced for an improved spectral reconstruction. Accompanying the tD65A ICS, m important basis vectors for the metameric black space based on the new spectral decomposition, and a mapping matrix MP,k via a polynomial model of order k, were trained so that both the spectral and colorimetric accuracies for the reconstructed reflectance can be further enhanced. The proposed ICS and its reconstruction method can ensure exact colorimetric matches under two (real rather than synthetic) illuminants D65 and A, which is an advantage compared with other ICSs. The performance of the proposed method was tested and compared with five other ICSs using the NCS dataset and three spectral images respectively, using RMSE and GFC to measure the spectral accuracy, and using CIEDE2000 colour differences to measure the colorimetric accuracy under three types of illuminants (continuous, fluorescent, and LED). Performance test results showed the proposed methods outperform other ICSs in terms of both spectral accuracy and colorimetric measures (RMSE, GFC, and CIEDE2000 colour difference). Therefore, it is expected the proposed ICS and its reconstruction method can play an important role in spectral image compression and reproduction applications.

STUDY OF K2SiF6:Mn4+@SiO2 PHOSPHOR FOR WHITE LEDS WITH HIGH ANGULAR COLOR UNIFORMITY

“…The device produces white ray by fusing one blue InGaN LED chip with one yellow phosphor called Y 3 Al 5 O 1 2:Ce 3 + (YGA:Ce) [3]. Nevertheless, its use in lighting and display is severely constrained by its poor hue rendering index (CRI) and elevated correlated color temperature (CCT) [4].…”