BabelColor ®
Color Measurement and Analysis
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CT&A Color Rendering Index (CRI)

tools and file options 

The Color Rendering Index tools can accept measurements from an instrument or from a file; a connected instrument is not required. For file input, spectral data can be provided in either 5 nm or 10 nm intervals. The CRI tools comprise the current CRI method (CIE 13.3: 1995) and three proposed replacement metrics: the Color Quality Scale (CQS, NIST Version 9.0.3), the CRI2012 (nCRI Version 12.0), and the TM-30-15 Method (IES, 2015). It also computes specifically designed metrics for gamut area (GAI: Gamut Area Index) and memory colors (MCRI: Memory Color Rendering Index).  The screenshot above shows the results associated to the standard CIE fluorescent lamp #4. Below is a list of the data you get from such a measurement. Some of the data is available through the selection menus located in the upper-right of the window. Test source data: CCT (kelvin); Duv (CIE1960); brightness (lux); LER (Light efficiency Ratio, in lm/W); the Reference source (a blackbody or a D-Series illuminant). CRI (Color Rendering Index): A graph of the 14 individual indices and Ra; numerical values of Ra (a general score based on the first 8 indices and better known as the current CRI),  R9, R(9-14) (for indices 9 to 14) and R(1-14) for indices 1 to 14; a graph of the samples (a*, b*) coordinates; a representation of the samples illuminated by the Reference and Test sources; the CIELAB color difference between the patches. CQS (Color Quality Scale, NIST Version 9.0.3): A graph of the 15 individual indices and Qa; numerical values of Qa (general score based on the 15 indices), Qf (fidelity index) and  Qg (relative gamut area); a graph of the samples (a*, b*) coordinates; a representation of the samples illuminated by the Reference and Test sources; the CIELAB color difference between the patches. CRI2012 (nCRI Version 12.0): A graph of the 17 individual indices and Ra,2012; numerical value of Ra,2012 (based on the 17 indices); a graph of the samples (a'M, b'M) coordinates; a representation of the samples illuminated by the Reference and Test sources; the color difference between the patches. TM-30-15 (IES, 2015): Numerical values of the Fidelity Index (Rf), the Gamut Index (Rg); the fidelity index for skin (Rf,skin), the color fidelity (Rfces) for each of the 99 Color Evaluation Sample (CES), the color fidelity (Rfh) for each of the 16 Hue Angle Bins, the chromaticity coordinates (J’a’b’) of all CES reference and test patches, the color difference (DeltaE’) for each set of CES patches, the average chromaticity coordinates (a'M, b'M)) of the Hue Angle Bins, and of the normalized chromaticity data used to draw the Color Vector Graphic (CVG). A graph of the reference source, which is different from the source used in other color rendering metrics when the CCT is between 4500 K and 5500 K; a bar graph of the color fidelity by sample (Rfces); a bar graph of the color fidelity by Hue Angle Bin (Rfh); a graph of the average chromaticity (a'M, b'M)) of the reference and test data of the Hue Angle Bins, which is used to compute the gamut area; a Color Vector Graphic (CVG) used to evaluate color saturation and desaturation; a plot of Rg versus Rf; and a visual representation of the 99 CES reference and test patches. GAI (Gamut Area Index): The GAI index. GAI and Ra: The arithmetic mean of GAI and Ra (the current CRI). MCRI (Memory Color Rendering Index): Rm (general memory color quality index); Sa (degree of similarity);  Si (special color quality indicators of the ten objects). You will find a description of each metric, a presentation of the interface, the input file requirements, the ranges of each metric, and a presentation of the export dialog in the CT&A Help manual. Complete specifications for these tools as well as the published scientific papers used as references when implementing the metrics can be found in the help manual and in the CT&A Specifications page on this Web site. Additional support material: Application Note: AN-11 The effects of a 10 nm bandwidth on data derived from spectrophotometer measurements. (description and download) TM-30-15 SPD data base: Files with the Spectral Power Distribution (SPD) of more than 500 light sources. (description and download) You can save data from multiple measurements in a single report file or save data in separate files for each measurement, or both options. The export options are shown in the screenshot below.
BabelColor ®

CT&A Color Rendering Index (CRI)

tools and file options 

The Color Rendering Index tools can accept measurements from an instrument or from a file; a connected instrument is not required. For file input, spectral data can be provided in either 5 nm or 10 nm intervals. The CRI tools comprise the current CRI method (CIE 13.3: 1995) and three proposed replacement metrics: the Color Quality Scale (CQS, NIST Version 9.0.3), the CRI2012 (nCRI Version 12.0), and the TM-30-15 Method (IES, 2015). It also computes specifically designed metrics for gamut area (GAI: Gamut Area Index) and memory colors (MCRI: Memory Color Rendering Index).   The screenshot above shows the results associated to the standard CIE fluorescent lamp #4. Below is a list of the data you get from such a measurement. Some of the data is available through the selection menus located in the upper-right of the window. Test source data: CCT (kelvin); Duv (CIE1960); brightness (lux); LER (Light efficiency Ratio, in lm/W); the Reference source (a blackbody or a D- Series illuminant). CRI (Color Rendering Index): A graph of the 14 individual indices and Ra; numerical values of Ra (a general score based on the first 8 indices and better known as the current CRI),  R9, R(9-14) (for indices 9 to 14) and R(1-14) for indices 1 to 14; a graph of the samples (a*, b*) coordinates; a representation of the samples illuminated by the Reference and Test sources; the CIELAB color difference between the patches. CQS (Color Quality Scale, NIST Version 9.0.3): A graph of the 15 individual indices and Qa; numerical values of Qa (general score based on the 15 indices), Qf (fidelity index) and  Qg (relative gamut area); a graph of the samples (a*, b*) coordinates; a representation of the samples illuminated by the Reference and Test sources; the CIELAB color difference between the patches. CRI2012 (nCRI Version 12.0): A graph of the 17 individual indices and Ra,2012; numerical value of Ra,2012 (based on the 17 indices); a graph of the samples (a'M, b'M) coordinates; a representation of the samples illuminated by the Reference and Test sources; the color difference between the patches. TM-30-15 (IES, 2015): Numerical values of the Fidelity Index (Rf), the Gamut Index (Rg); the fidelity index for skin (Rf,skin), the color fidelity (Rfces) for each of the 99 Color Evaluation Sample (CES), the color fidelity (Rfh) for each of the 16 Hue Angle Bins, the chromaticity coordinates (J’a’b’) of all CES reference and test patches, the color difference (DeltaE’) for each set of CES patches, the average chromaticity coordinates (a'M, b'M)) of the Hue Angle Bins, and of the normalized chromaticity data used to draw the Color Vector Graphic (CVG). A graph of the reference source, which is different from the source used in other color rendering metrics when the CCT is between 4500 K and 5500 K; a bar graph of the color fidelity by sample (Rfces); a bar graph of the color fidelity by Hue Angle Bin (Rfh); a graph of the average chromaticity (a'M, b'M)) of the reference and test data of the Hue Angle Bins, which is used to compute the gamut area; a Color Vector Graphic (CVG) used to evaluate color saturation and desaturation; a plot of Rg versus Rf; and a visual representation of the 99 CES reference and test patches. GAI (Gamut Area Index): The GAI index. GAI and Ra: The arithmetic mean of GAI and Ra  (the current CRI). MCRI (Memory Color Rendering Index): Rm  (general memory color quality index); Sa (degree of similarity);  Si (special color quality indicators of the ten objects). You will find a description of each metric, a presentation of the interface, the input file requirements, the ranges of each metric, and a presentation of the export dialog in the CT&A Help manual. Complete specifications for these tools as well as the published scientific papers used as references when implementing the metrics can be found in the help manual and in the CT&A Specifications page on this Web site. Additional support material: Application Note: AN-11 The effects of a 10 nm bandwidth on data derived from spectrophotometer measurements. (description and download) TM-30-15 SPD data base: Files with the Spectral Power Distribution (SPD) of more than 500 light sources. (description and download) You can save data from multiple measurements in a single report file or save data in separate files for each measurement, or both options. The export options are shown in the screenshot below.
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