DOI: 

Optoelektron. napìvprovìd. teh. 61, 165-170 (2026)

К.V. Hovorova, P.P. Hovorov, Y.S. Hryhorieva. 

CALCULATION of the COLOR RENDERING INDEX by DETERMINING COLOR DIFFERENCES USING the CIEDE2000 ALGORITHM 

Over the last century, the importance of accurately reproducing the colors of illuminated objects has become increasingly evident in both scientific research and practical applications. As artificial lighting technologies have advanced and become more widespread, the ability of a light source to faithfully render colors has emerged as a critical factor in many areas of human activity. In numerous professional fields, including medicine, manufacturing, photography, art, retail, and industrial inspection, successful task performance depends heavily on the accurate perception and representation of colors under artificial illumination conditions. Even slight distortions in color appearance may lead to errors in judgment, reduced productivity, or lower quality of work.

In addition to its impact on visual performance and productivity, lighting quality also plays a major role in ensuring employee health, comfort, and workplace safety. Poor color rendering can contribute to visual fatigue, eye strain, and difficulties in distinguishing objects or warning signals, particularly in environments where precise visual recognition is essential. Therefore, the evaluation of lighting systems requires not only consideration of luminous efficiency and brightness, but also the quality with which colors are reproduced.

To address these challenges and provide a standardized method for assessing the color reproduction capabilities of light sources, the Color Rendering Index (CRI) was introduced in 1965. The CRI method was developed to compare how accurately a test light source renders the colors of objects in comparison with a reference light source. Since its introduction, CRI has become one of the most widely used metrics for evaluating the color rendering performance of lamps and lighting systems across a broad range of applications.

Determining a reference light source based on the color difference calculation is a crucial part of the CRI calculation. By employing a reference emitter with a color temperature that is as mathematically close to the examined light source as feasible, this method seeks to reduce uncertainty. However, this criterion ignores some of the quirks of how the human eye perceives color. In order to address the aforementioned issue, the colorimetry standards now in use were taken into consideration. Based on the analysis, the color rendering index was initially calculated using the color difference formula, which offers a more thorough method of determining CRI.

Keywords: color rendering index, color difference, reference light source, color and chromaticity coordinates.