Multi-Spectral to XYZ - Integration

multi_spectral_to_XYZ_integration.py

#%%
import glob
import numpy as np

import colour
from colour import (DEFAULT_SPECTRAL_SHAPE, STANDARD_OBSERVERS_CMFS, ones_spd,
                    read_image)
from colour.utilities import tsplit, tstack, warning
from colour.plotting import image_plot

tifs_images = glob.glob('/Users/kelsolaar/Downloads/MetaCow/SmTiffs/*.tif')
RGB = [read_image(tifs_image) for tifs_image in tifs_images]

RGB = tstack(RGB)


#%%
def multi_spectral_to_XYZ_integration(
        a,
        shape=DEFAULT_SPECTRAL_SHAPE,
        cmfs=STANDARD_OBSERVERS_CMFS['CIE 1931 2 Degree Standard Observer'],
        illuminant=ones_spd(STANDARD_OBSERVERS_CMFS[
            'CIE 1931 2 Degree Standard Observer'].shape)):

    if cmfs.shape != shape:
        warning('Aligning "{0}" cmfs shape to "{1}".'.format(cmfs.name, shape))
        cmfs = cmfs.copy().align(shape)

    if illuminant.shape != shape:
        warning('Aligning "{0}" illuminant shape to "{1}".'.format(
            illuminant.name, shape))
        illuminant = illuminant.copy().align(shape)

    S = illuminant.values
    x_bar, y_bar, z_bar = tsplit(cmfs.values)
    dw = cmfs.shape.interval

    k = 100 / (np.sum(y_bar * S) * dw)

    X_p = a * x_bar * S * dw
    Y_p = a * y_bar * S * dw
    Z_p = a * z_bar * S * dw

    XYZ = k * np.sum(np.array([X_p, Y_p, Z_p]), axis=-1)

    return np.rollaxis(XYZ, 0, 3)


XYZ = multi_spectral_to_XYZ_integration(
    RGB,
    colour.SpectralShape(380, 760, 5),
    illuminant=colour.ILLUMINANTS_RELATIVE_SPDS['D65'])

image_plot(colour.XYZ_to_sRGB(XYZ / 100))

MetaCow