"""
Demonstrate *CIECAM02* colour appearance model computations.

This module provides examples of colour appearance model computations using the
*CIECAM02* model, illustrating both forward and inverse transformations between
tristimulus values and colour appearance correlates.
"""

import numpy as np

import colour
from colour.utilities import message_box

message_box('Compute "CIECAM02" Colour Appearance Model Correlates')

XYZ = np.array([19.01, 20.00, 21.78])
XYZ_w = np.array([95.05, 100.00, 108.88])
L_A = 318.31
Y_b = 20.0
surround = colour.VIEWING_CONDITIONS_CIECAM02["Average"]
message_box(
    f'Convert to the "CIECAM02" colour appearance model specification '
    f"using given parameters:\n\n"
    f"\tXYZ: {XYZ}\n"
    f"\tXYZ_w: {XYZ_w}\n"
    f"\tL_A: {L_A}\n"
    f"\tY_b: {Y_b}\n"
    f"\tSurround: {surround}"
)
specification = colour.XYZ_to_CIECAM02(XYZ, XYZ_w, L_A, Y_b, surround)
print(specification)

print("\n")

J = 41.73109113
C = 0.10470776
h = 219.04843266
specification = colour.CAM_Specification_CIECAM02(J, C, h)
message_box(
    f'Convert to "CIE XYZ" tristimulus values using given parameters:\n\n'
    f"\tJ: {J}\n"
    f"\tC: {C}\n"
    f"\th: {h}\n"
    f"\tXYZ_w: {XYZ_w}\n"
    f"\tL_A: {L_A}\n"
    f"\tY_b: {Y_b}\n"
    f"\tSurround: {surround}"
)
print(colour.CIECAM02_to_XYZ(specification, XYZ_w, L_A, Y_b, surround))
