PLASA ANSI E1.54 - Whitepoint Derivation

plasa_ansi_e154.py

# Standard claims at https://webstore.ansi.org/preview-pages/ESTA/preview_ANSI+E1.54-2015.pdf gives [0.4254, 0.4044]

import colour

# Blackbody: 360, 780, 1nm
# CIE 1931 2 Degree Standard Observer: 360, 780, 1nm
# Method: ASTM E308
print(
    colour.XYZ_to_xy(
        colour.sd_to_XYZ(
            colour.sd_blackbody(3200),
            colour.MSDS_CMFS["CIE 1931 2 Degree Standard Observer"],
        )
    ).round(4)
)
# [ 0.4234  0.399 ]

# Blackbody: 360, 780, 1nm
# CIE 1964 10 Degree Standard Observer: 360, 780, 1nm
# Method: ASTM E308
print(
    colour.XYZ_to_xy(
        colour.sd_to_XYZ(
            colour.sd_blackbody(3200),
            colour.MSDS_CMFS["CIE 1964 10 Degree Standard Observer"],
        )
    ).round(4)
)
# [ 0.4266  0.3976]

# Blackbody: 400, 700, 10nm
# CIE 1931 2 Degree Standard Observer: 360, 780, 1nm
# Method: ASTM E308
print(
    colour.XYZ_to_xy(
        colour.sd_to_XYZ(
            colour.sd_blackbody(3200, shape=colour.SpectralShape(400, 700, 10)),
            colour.MSDS_CMFS["CIE 1931 2 Degree Standard Observer"],
        )
    ).round(4)
)
# [ 0.4233  0.3989]

# Blackbody: 400, 700, 10nm
# CIE 1931 2 Degree Standard Observer: 400, 700, 10nm
# Method: Integration
print(
    colour.XYZ_to_xy(
        colour.sd_to_XYZ(
            colour.sd_blackbody(3200, shape=colour.SpectralShape(400, 700, 10)),
            colour.MSDS_CMFS["CIE 1931 2 Degree Standard Observer"]
            .copy()
            .align(colour.SpectralShape(400, 700, 10)),
            method="Integration",
        )
    ).round(4)
)
# [ 0.4231  0.3993]