""" DIN99 Colourspace and DIN99b, DIN99c, DIN99d Refined Formulas ============================================================= Define the *DIN99* colourspace and *DIN99b*, *DIN99c*, *DIN99d* refined formulas transformations. - :func:`colour.Lab_to_DIN99` - :func:`colour.DIN99_to_Lab` - :func:`colour.XYZ_to_DIN99` - :func:`colour.DIN99_to_XYZ` References ---------- - :cite:`ASTMInternational2007` : ASTM International. (2007). ASTM D2244-07 - Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates: Vol. i (pp. 1-10). doi:10.1520/D2244-16 - :cite:`Cui2002` : Cui, G., Luo, M. R., Rigg, B., Roesler, G., & Witt, K. (2002). Uniform colour spaces based on the DIN99 colour-difference formula. Color Research & Application, 27(4), 282-290. doi:10.1002/col.10066 """ from __future__ import annotations import typing import numpy as np from colour.algebra import spow from colour.colorimetry import CCS_ILLUMINANTS if typing.TYPE_CHECKING: from colour.hints import Literal from colour.hints import ( # noqa: TC001 ArrayLike, Domain1, Domain100, Range1, Range100, ) from colour.models import Lab_to_XYZ, XYZ_to_Lab from colour.utilities import ( CanonicalMapping, from_range_100, to_domain_100, tsplit, tstack, validate_method, ) __author__ = "Colour Developers" __copyright__ = "Copyright 2013 Colour Developers" __license__ = "BSD-3-Clause - https://opensource.org/licenses/BSD-3-Clause" __maintainer__ = "Colour Developers" __email__ = "colour-developers@colour-science.org" __status__ = "Production" __all__ = [ "DIN99_METHODS", "Lab_to_DIN99", "DIN99_to_Lab", "XYZ_to_DIN99", "DIN99_to_XYZ", ] DIN99_METHODS: CanonicalMapping = CanonicalMapping( { "ASTMD2244-07": np.array( [105.509, 0.0158, 16.0, 0.7, 1, 9 / 200, 0.0, 9 / 200] ), "DIN99": np.array([105.509, 0.0158, 16.0, 0.7, 1, 9 / 200, 0.0, 9 / 200]), "DIN99b": np.array([303.67, 0.0039, 26.0, 0.83, 23.0, 0.075, 26.0, 1]), "DIN99c": np.array([317.65, 0.0037, 0.0, 0.94, 23.0, 0.066, 0.0, 1]), "DIN99d": np.array([325.22, 0.0036, 50.0, 1.14, 22.5, 0.06, 50.0, 1]), } ) """ Supported *DIN99* colourspace methods, i.e., the coefficients for the *DIN99b*, *DIN99c*, and *DIN99d* refined formulas according to *Cui et al. (2002)*. References ---------- :cite:`ASTMInternational2007`, :cite:`Cui2002` """ def Lab_to_DIN99( Lab: Domain100, k_E: float = 1, k_CH: float = 1, method: ( Literal["ASTMD2244-07", "DIN99", "DIN99b", "DIN99c", "DIN99d"] | str ) = "DIN99", ) -> Range100: """ Convert from *CIE L\\*a\\*b\\** colourspace to *DIN99* colourspace or one of the *DIN99b*, *DIN99c*, *DIN99d* refined formulas according to *Cui et al. (2002)*. Parameters ---------- Lab *CIE L\\*a\\*b\\** colourspace array. k_E Parametric factor :math:`K_E` used to compensate for texture and other specimen presentation effects. k_CH Parametric factor :math:`K_{CH}` used to compensate for texture and other specimen presentation effects. method Computation method. Returns ------- :class:`numpy.ndarray` *DIN99* colourspace array. Notes ----- +------------+------------------------+--------------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+========================+====================+ | ``Lab`` | 100 | 1 | +------------+------------------------+--------------------+ +------------+------------------------+--------------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+========================+====================+ | ``Lab_99`` | 100 | 1 | +------------+------------------------+--------------------+ References ---------- :cite:`ASTMInternational2007`, :cite:`Cui2002` Examples -------- >>> import numpy as np >>> Lab = np.array([41.52787529, 52.63858304, 26.92317922]) >>> Lab_to_DIN99(Lab) # doctest: +ELLIPSIS array([ 53.2282198..., 28.4163465..., 3.8983955...]) """ c_1, c_2, c_3, c_4, c_5, c_6, c_7, c_8 = DIN99_METHODS[ validate_method(method, tuple(DIN99_METHODS)) ] L, a, b = tsplit(to_domain_100(Lab)) cos_c = np.cos(np.radians(c_3)) sin_c = np.sin(np.radians(c_3)) e = cos_c * a + sin_c * b f = c_4 * (-sin_c * a + cos_c * b) G = spow(e**2 + f**2, 0.5) h_ef = np.arctan2(f, e) + np.radians(c_7) C_99 = c_5 * (np.log1p(c_6 * G)) / (c_8 * k_CH * k_E) # Hue angle is unused currently. # h_99 = np.degrees(h_ef) a_99 = C_99 * np.cos(h_ef) b_99 = C_99 * np.sin(h_ef) L_99 = c_1 * (np.log1p(c_2 * L)) * k_E Lab_99 = tstack([L_99, a_99, b_99]) return from_range_100(Lab_99) def DIN99_to_Lab( Lab_99: Domain100, k_E: float = 1, k_CH: float = 1, method: ( Literal["ASTMD2244-07", "DIN99", "DIN99b", "DIN99c", "DIN99d"] | str ) = "DIN99", ) -> Range100: """ Convert from *DIN99* colourspace or one of the *DIN99b*, *DIN99c*, *DIN99d* refined formulas according to *Cui et al. (2002)* to *CIE L\\*a\\*b\\** colourspace. Parameters ---------- Lab_99 *DIN99* colourspace array. k_E Parametric factor :math:`K_E` used to compensate for texture and other specimen presentation effects. k_CH Parametric factor :math:`K_{CH}` used to compensate for texture and other specimen presentation effects. method Computation method. Returns ------- :class:`numpy.ndarray` *CIE L\\*a\\*b\\** colourspace array. Notes ----- +------------+------------------------+--------------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +============+========================+====================+ | ``Lab_99`` | 100 | 1 | +------------+------------------------+--------------------+ +------------+------------------------+--------------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+========================+====================+ | ``Lab`` | 100 | 1 | +------------+------------------------+--------------------+ References ---------- :cite:`ASTMInternational2007`, :cite:`Cui2002` Examples -------- >>> import numpy as np >>> Lab_99 = np.array([53.22821988, 28.41634656, 3.89839552]) >>> DIN99_to_Lab(Lab_99) # doctest: +ELLIPSIS array([ 41.5278752..., 52.6385830..., 26.9231792...]) """ c_1, c_2, c_3, c_4, c_5, c_6, c_7, c_8 = DIN99_METHODS[ validate_method(method, tuple(DIN99_METHODS)) ] L_99, a_99, b_99 = tsplit(to_domain_100(Lab_99)) cos = np.cos(np.radians(c_3)) sin = np.sin(np.radians(c_3)) h_99 = np.arctan2(b_99, a_99) - np.radians(c_7) C_99 = np.hypot(a_99, b_99) G = np.expm1((c_8 / c_5) * C_99 * k_CH * k_E) / c_6 e = G * np.cos(h_99) f = G * np.sin(h_99) a = e * cos - (f / c_4) * sin b = e * sin + (f / c_4) * cos L = np.expm1(L_99 * k_E / c_1) / c_2 Lab = tstack([L, a, b]) return from_range_100(Lab) def XYZ_to_DIN99( XYZ: Domain1, illuminant: ArrayLike = CCS_ILLUMINANTS["CIE 1931 2 Degree Standard Observer"][ "D65" ], k_E: float = 1, k_CH: float = 1, method: ( Literal["ASTMD2244-07", "DIN99", "DIN99b", "DIN99c", "DIN99d"] | str ) = "DIN99", ) -> Range100: """ Convert from *CIE XYZ* tristimulus values to *DIN99* colourspace or one of the *DIN99b*, *DIN99c*, *DIN99d* refined formulas according to *Cui et al. (2002)*. Parameters ---------- XYZ *CIE XYZ* tristimulus values. illuminant Reference *illuminant* *CIE xy* chromaticity coordinates or *CIE xyY* colourspace array. k_E Parametric factor :math:`K_E` used to compensate for texture and other specimen presentation effects. k_CH Parametric factor :math:`K_{CH}` used to compensate for texture and other specimen presentation effects. method Computation method. Returns ------- :class:`numpy.ndarray` *DIN99* colourspace array. Notes ----- +----------------+-----------------------+-----------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +================+=======================+=================+ | ``XYZ`` | 1 | 1 | +----------------+-----------------------+-----------------+ | ``illuminant`` | 1 | 1 | +----------------+-----------------------+-----------------+ +------------+------------------------+--------------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +============+========================+====================+ | ``Lab_99`` | 100 | 1 | +------------+------------------------+--------------------+ References ---------- :cite:`ASTMInternational2007` Examples -------- >>> import numpy as np >>> XYZ = np.array([0.20654008, 0.12197225, 0.05136952]) >>> XYZ_to_DIN99(XYZ) # doctest: +ELLIPSIS array([ 53.2282198..., 28.4163465..., 3.8983955...]) """ Lab = XYZ_to_Lab(XYZ, illuminant) return Lab_to_DIN99(Lab, k_E, k_CH, method) def DIN99_to_XYZ( Lab_99: Domain100, illuminant: ArrayLike = CCS_ILLUMINANTS["CIE 1931 2 Degree Standard Observer"][ "D65" ], k_E: float = 1, k_CH: float = 1, method: ( Literal["ASTMD2244-07", "DIN99", "DIN99b", "DIN99c", "DIN99d"] | str ) = "DIN99", ) -> Range1: """ Convert from *DIN99* colourspace or one of the *DIN99b*, *DIN99c*, *DIN99d* refined formulas according to *Cui et al. (2002)* to *CIE XYZ* tristimulus values. Parameters ---------- Lab_99 *DIN99* colourspace array. illuminant Reference *illuminant* *CIE xy* chromaticity coordinates or *CIE xyY* colourspace array. k_E Parametric factor :math:`K_E` used to compensate for texture and other specimen presentation effects. k_CH Parametric factor :math:`K_{CH}` used to compensate for texture and other specimen presentation effects. method Computation method. Returns ------- :class:`numpy.ndarray` *CIE XYZ* tristimulus values. Notes ----- +----------------+------------------------+--------------------+ | **Domain** | **Scale - Reference** | **Scale - 1** | +================+========================+====================+ | ``Lab_99`` | 100 | 1 | +----------------+------------------------+--------------------+ | ``illuminant`` | 1 | 1 | +----------------+------------------------+--------------------+ +----------------+-----------------------+---------------------+ | **Range** | **Scale - Reference** | **Scale - 1** | +================+=======================+=====================+ | ``XYZ`` | 1 | 1 | +----------------+-----------------------+---------------------+ References ---------- :cite:`ASTMInternational2007` Examples -------- >>> import numpy as np >>> Lab_99 = np.array([53.22821989, 28.41634656, 3.89839552]) >>> DIN99_to_XYZ(Lab_99) # doctest: +ELLIPSIS array([ 0.2065400..., 0.1219722..., 0.0513695...]) """ Lab = DIN99_to_Lab(Lab_99, k_E, k_CH, method) return Lab_to_XYZ(Lab, illuminant)