ABSTRACT
Recently, Ohno proposed a method for computing the correlated color temperature (CCT) of a light source and the shortest distance (with sign) between its chromaticity and that of the Planckian locus (Duv). In Ohno’s method, firstly a lookup table is chosen, and then a hybrid method based on the triangular and parabolic solutions is used to predict the CCT and Duv of a given light source. In this article, we found that spline interpolation is better than the parabolic solution for predicting CCT and Duv. Therefore, we propose two new hybrid methods based on the triangular and either spline interpolation or third-order interpolation using two local function values and two local second-order derivative values. Comprehensive tests using the lookup table with both 1% and 0.25% increments relative to the current selected color temperature demonstrate that the proposed methods outperform Ohno’s method.
OCIS CODES
330.1690; 330.1710; 330.1730
OCIS CODES
330.1690; 330.1710; 330.1730
Acknowledgments
The authors thank Donald J. Murphy McVeigh for his help with English editing.
Disclosure statement
The authors have no financial interests to declare.