Calibration Method for Measuring the Color Rendering Index (CRI) using RGB Sensor

Abstract

Color is a perceptual characteristic, derived from the light reflected on the object and as such does not represent a physical property. However, progress has been made in building mathematical models to define it more clearly. Light sources play a key role in color perception, and one of the measures to characterize the effect is the Color Rendering Index (CRI). The CRI is a measure used to characterize the color reproduction ability of a light source in particular in comparison with ideal light source. In this work, initially developed an algorithm to determine the CRI from SPD and then used a low-cost RGB sensor to find a model that would estimate the value CRI directly. We used four groups of light sources with technical information available, we measured the SPD and found a transformation matrix to convert RGB to XYZ space. This work is framed in the development of tools to control and lighting measurements for environment control tasks and characterization of artificial sources.