Xyz2rgb

import numpy as np

def xyz2rgb(xyz, white_point='D50'):
    # Normalize XYZ if not already normalized
    xyz = np.array(xyz, dtype=np.float32)  # Ensure the array is in float
    xyz /= np.max(xyz)

    if white_point == 'D65':
        # White point adaptation matrix from D65 to D50 using Bradford transformation
        M_D65_to_D50 = np.array([
            [ 0.9555766, -0.0230393,  0.0631636],
            [-0.0282895,  1.0099416,  0.0210077],
            [ 0.0122982, -0.0204830,  1.3299098]
        ])
        # Reshape xyz to (n, 3) for matrix multiplication
        xyz_flat = xyz.reshape(-1, 3)
        # Apply the white point adaptation
        xyz_d50_flat = np.dot(xyz_flat, M_D65_to_D50.T)
        # Reshape back to original shape
        xyz_d50 = xyz_d50_flat.reshape(xyz.shape)
    else:
        # No adaptation needed if already in D50
        xyz_d50 = xyz

    # Transformation matrix from XYZ (D50) to linear RGB (sRGB color space)
    M_XYZ_to_RGB_D50 = np.array([
        [ 3.1338561, -1.6168667, -0.4906146],
        [-0.9787684,  1.9161415,  0.0334540],
        [ 0.0719453, -0.2289914,  1.4052427]
    ])

    # Reshape xyz_d50 to (n, 3) for matrix multiplication
    xyz_d50_flat = xyz_d50.reshape(-1, 3)

    # Apply the transformation to get linear RGB
    rgb_linear_flat = np.dot(xyz_d50_flat, M_XYZ_to_RGB_D50.T)

    # Reshape back to original shape
    rgb_linear = rgb_linear_flat.reshape(xyz_d50.shape)

    # Gamma correction function
    def gamma_correction(channel):
        return np.where(channel <= 0.0031308,
                        12.92 * channel,
                        1.055 * np.power(channel, 1/2.4) - 0.055)

    # Apply gamma correction
    rgb_srgb = gamma_correction(rgb_linear)

    # Clip values to the range [0, 1]
    rgb_srgb = np.clip(rgb_srgb, 0, 1)

    return rgb_srgb

# Example usage:
# Assuming `xyz_data` is your input ndarray of shape (600, 800, 3)
# xyz_data = np.random.random((600, 800, 3))  # Replace with actual data
# rgb_data = xyz2rgb(xyz_data, white_point='D65')