def xyz_to_cct_HA(xyzw):
"""
Convert XYZ tristimulus values to correlated color temperature (CCT).
Args:
:xyzw:
| ndarray of tristimulus values
Returns:
:cct:
| ndarray of correlated color temperatures estimates
References:
1. `Hernández-Andrés, Javier; Lee, RL; Romero, J (September 20, 1999).
Calculating Correlated Color Temperatures Across the Entire Gamut
of Daylight and Skylight Chromaticities.
Applied Optics. 38 (27), 5703–5709. P
<https://www.osapublishing.org/ao/abstract.cfm?uri=ao-38-27-5703>`_
Notes:
According to paper small error from 3000 - 800 000 K, but a test with
Planckians showed errors up to 20% around 500 000 K;
e>0.05 for T>200 000, e>0.1 for T>300 000, ...
"""
if len(xyzw.shape)>2:
raise Exception('xyz_to_cct_HA(): Input xyzw.ndim must be <= 2 !')
out_of_range_code = np.nan
xe = [0.3366, 0.3356]
ye = [0.1735, 0.1691]
A0 = [-949.86315, 36284.48953]
A1 = [6253.80338, 0.00228]
t1 = [0.92159, 0.07861]
A2 = [28.70599, 5.4535*1e-36]
t2 = [0.20039, 0.01543]
A3 = [0.00004, 0.0]
t3 = [0.07125,1.0]
cct_ranges = np.array([[3000.0,50000.0],[50000.0,800000.0]])
Yxy = xyz_to_Yxy(xyzw)
CCT = np.ones((1,Yxy.shape[0]))*out_of_range_code
for i in range(2):
n = (Yxy[:,1]-xe[i])/(Yxy[:,2]-ye[i])
CCT_i = np2d(np.array(A0[i] + A1[i]*np.exp(np.divide(-n,t1[i])) + A2[i]*np.exp(np.divide(-n,t2[i])) + A3[i]*np.exp(np.divide(-n,t3[i]))))
p = (CCT_i >= (1.0-0.05*(i == 0))*cct_ranges[i][0]) & (CCT_i < (1.0+0.05*(i == 0))*cct_ranges[i][1])
CCT[p] = CCT_i[p]
p = (CCT_i < (1.0-0.05)*cct_ranges[0][0]) #smaller than smallest valid CCT value
CCT[p] = -1
if (np.isnan(CCT.sum()) == True) | (np.any(CCT == -1)):
print("Warning: xyz_to_cct_HA(): one or more CCTs out of range! --> (CCT < 3 kK, CCT >800 kK) coded as (-1, NaN) 's")
return CCT.T
def xyz_to_cct_search(xyzw,
cieobs=_CIEOBS,
out='cct',
wl=None,
accuracy=0.1,
upper_cct_max=10.0**20,
approx_cct_temp=True):
"""
Convert XYZ tristimulus values to correlated color temperature (CCT) and
Duv(distance above (> 0) or below ( < 0) the Planckian locus) by a
brute-force search.
| The algorithm uses an approximate cct_temp (HA approx., see xyz_to_cct_HA)
as starting point or uses the middle of the allowed cct-range
(1e2 K - 1e20 K, higher causes overflow) on a log-scale, then constructs
a 4-step section of the blackbody (Planckian) locus on which to find the
minimum distance to the 1960 uv chromaticity of the test source.
Args:
:xyzw:
| ndarray of tristimulus values
:cieobs:
| luxpy._CIEOBS, optional
| CMF set used to calculated xyzw.
:out:
| 'cct' (or 1), optional
| Determines what to return.
| Other options: 'duv' (or -1), 'cct,duv'(or 2), "[cct,duv]" (or -2)
:wl:
| None, optional
| Wavelengths used when calculating Planckian radiators.
:accuracy:
| float, optional
| Stop brute-force search when cct :accuracy: is reached.
:upper_cct_max:
| 10.0**20, optional
| Limit brute-force search to this cct.
:approx_cct_temp:
| True, optional
| If True: use xyz_to_cct_HA() to get a first estimate of cct to
speed up search.
Returns:
:returns:
| ndarray with:
| cct: out == 'cct' (or 1)
| duv: out == 'duv' (or -1)
| cct, duv: out == 'cct,duv' (or 2)
| [cct,duv]: out == "[cct,duv]" (or -2)
Notes:
This program is more accurate, but slower than xyz_to_cct_ohno!
Note that cct must be between 1e3 K - 1e20 K
(very large cct take a long time!!!)
"""
xyzw = np2d(xyzw)
if len(xyzw.shape) > 2:
raise Exception('xyz_to_cct_search(): Input xyzw.shape must be <= 2 !')
# get 1960 u,v of test source:
Yuvt = xyz_to_Yuv(np.squeeze(
xyzw)) # remove possible 1-dim + convert xyzw to CIE 1976 u',v'
#axis_of_v3t = len(Yuvt.shape)-1 # axis containing color components
ut = Yuvt[:, 1, None] #.take([1],axis = axis_of_v3t) # get CIE 1960 u
vt = (2 / 3) * Yuvt[:, 2,
None] #.take([2],axis = axis_of_v3t) # get CIE 1960 v
# Initialize arrays:
ccts = np.ones((xyzw.shape[0], 1)) * np.nan
duvs = ccts.copy()
#calculate preliminary solution(s):
if (approx_cct_temp == True):
ccts_est = xyz_to_cct_HA(xyzw)
procent_estimates = np.array([[3000.0, 100000.0, 0.05],
[100000.0, 200000.0, 0.1],
[200000.0, 300000.0, 0.25],
[300000.0, 400000.0, 0.4],
[400000.0, 600000.0, 0.4],
[600000.0, 800000.0, 0.4],
[800000.0, np.inf, 0.25]])
else:
upper_cct = np.array(upper_cct_max)
lower_cct = np.array(10.0**2)
cct_scale_fun = lambda x: np.log10(x)
cct_scale_ifun = lambda x: np.power(10.0, x)
dT = (cct_scale_fun(upper_cct) - cct_scale_fun(lower_cct)) / 2
ccttemp = np.array([cct_scale_ifun(cct_scale_fun(lower_cct) + dT)])
ccts_est = np2d(ccttemp * np.ones((xyzw.shape[0], 1)))
dT_approx_cct_False = dT.copy()
# Loop through all ccts:
for i in range(xyzw.shape[0]):
#initialize CCT search parameters:
cct = np.nan
duv = np.nan
ccttemp = ccts_est[i].copy()
# Take care of (-1, NaN)'s from xyz_to_cct_HA signifying (CCT < lower, CCT > upper) bounds:
approx_cct_temp_temp = approx_cct_temp
if (approx_cct_temp == True):
cct_scale_fun = lambda x: x
cct_scale_ifun = lambda x: x
if (ccttemp != -1) & (
np.isnan(ccttemp) == False
): # within validity range of CCT estimator-function
for ii in range(procent_estimates.shape[0]):
if (ccttemp >=
(1.0 - 0.05 *
(ii == 0)) * procent_estimates[ii, 0]) & (
ccttemp < (1.0 + 0.05 *
(ii == 0)) * procent_estimates[ii, 1]):
procent_estimate = procent_estimates[ii, 2]
break
dT = np.multiply(
ccttemp, procent_estimate
) # determines range around CCTtemp (25% around estimate) or 100 K
elif (ccttemp == -1) & (np.isnan(ccttemp) == False):
ccttemp = np.array([procent_estimates[0, 0] / 2])
procent_estimate = 1 # cover 0 K to min_CCT of estimator
dT = np.multiply(ccttemp, procent_estimate)
elif (np.isnan(ccttemp) == True):
upper_cct = np.array(upper_cct_max)
lower_cct = np.array(10.0**2)
cct_scale_fun = lambda x: np.log10(x)
cct_scale_ifun = lambda x: np.power(10.0, x)
dT = (cct_scale_fun(upper_cct) - cct_scale_fun(lower_cct)) / 2
ccttemp = np.array(
[cct_scale_ifun(cct_scale_fun(lower_cct) + dT)])
approx_cct_temp = False
else:
dT = dT_approx_cct_False
nsteps = 3
signduv = 1.0
ccttemp = ccttemp[0]
delta_cct = dT
while ((delta_cct > accuracy)): # keep converging on CCT
#generate range of ccts:
ccts_i = cct_scale_ifun(
np.linspace(
cct_scale_fun(ccttemp) - dT,
cct_scale_fun(ccttemp) + dT, nsteps + 1))
ccts_i[ccts_i < 100.0] = 100.0 # avoid nan's in calculation
# Generate BB:
BB = cri_ref(ccts_i, wl3=wl, ref_type=['BB'], cieobs=cieobs)
# Calculate xyz:
xyz = spd_to_xyz(BB, cieobs=cieobs)
# Convert to CIE 1960 u,v:
Yuv = xyz_to_Yuv(np.squeeze(
xyz)) # remove possible 1-dim + convert xyz to CIE 1976 u',v'
#axis_of_v3 = len(Yuv.shape)-1 # axis containing color components
u = Yuv[:, 1, None] # get CIE 1960 u
v = (2.0 / 3.0) * Yuv[:, 2, None] # get CIE 1960 v
# Calculate distance between list of uv's and uv of test source:
dc = ((ut[i] - u)**2 + (vt[i] - v)**2)**0.5
if np.isnan(dc.min()) == False:
#eps = _EPS
q = dc.argmin()
if np.size(
q
) > 1: #to minimize calculation time: only calculate median when necessary
cct = np.median(ccts[q])
duv = np.median(dc[q])
q = np.median(q)
q = int(q) #must be able to serve as index
else:
cct = ccts_i[q]
duv = dc[q]
if (q == 0):
ccttemp = cct_scale_ifun(
np.array(cct_scale_fun([cct])) + 2 * dT / nsteps)
#dT = 2.0*dT/nsteps
continue # look in higher section of planckian locus
if (q == np.size(ccts_i)):
ccttemp = cct_scale_ifun(
np.array(cct_scale_fun([cct])) - 2 * dT / nsteps)
#dT = 2.0*dT/nsteps
continue # look in lower section of planckian locus
if (q > 0) & (q < np.size(ccts_i) - 1):
dT = 2 * dT / nsteps
# get Duv sign:
d_p1m1 = ((u[q + 1] - u[q - 1])**2.0 +
(v[q + 1] - v[q - 1])**2.0)**0.5
x = (dc[q - 1]**2.0 - dc[q + 1]**2.0 +
d_p1m1**2.0) / 2.0 * d_p1m1
vBB = v[q - 1] + ((v[q + 1] - v[q - 1]) * (x / d_p1m1))
signduv = np.sign(vt[i] - vBB)
#calculate difference with previous intermediate solution:
delta_cct = abs(cct - ccttemp)
ccttemp = np.array(cct) #%set new intermediate CCT
approx_cct_temp = approx_cct_temp_temp
else:
ccttemp = np.nan
cct = np.nan
duv = np.nan
duvs[i] = signduv * abs(duv)
ccts[i] = cct
# Regulate output:
if (out == 'cct') | (out == 1):
return np2d(ccts)
elif (out == 'duv') | (out == -1):
return np2d(duvs)
elif (out == 'cct,duv') | (out == 2):
return np2d(ccts), np2d(duvs)
elif (out == "[cct,duv]") | (out == -2):
return np.vstack((ccts, duvs)).T
def cie2006cmfsEx(age = 32,fieldsize = 10, wl = None,\
var_od_lens = 0, var_od_macula = 0, \
var_od_L = 0, var_od_M = 0, var_od_S = 0,\
var_shft_L = 0, var_shft_M = 0, var_shft_S = 0,\
out = 'LMS', allow_negative_values = False):
"""
Generate Individual Observer CMFs (cone fundamentals)
based on CIE2006 cone fundamentals and published literature
on observer variability in color matching and in physiological parameters.
Args:
:age:
| 32 or float or int, optional
| Observer age
:fieldsize:
| 10, optional
| Field size of stimulus in degrees (between 2° and 10°).
:wl:
| None, optional
| Interpolation/extraplation of :LMS: output to specified wavelengths.
| None: output original _WL = np.array([390,780,5])
:var_od_lens:
| 0, optional
| Std Dev. in peak optical density [%] of lens.
:var_od_macula:
| 0, optional
| Std Dev. in peak optical density [%] of macula.
:var_od_L:
| 0, optional
| Std Dev. in peak optical density [%] of L-cone.
:var_od_M:
| 0, optional
| Std Dev. in peak optical density [%] of M-cone.
:var_od_S:
| 0, optional
| Std Dev. in peak optical density [%] of S-cone.
:var_shft_L:
| 0, optional
| Std Dev. in peak wavelength shift [nm] of L-cone.
:var_shft_L:
| 0, optional
| Std Dev. in peak wavelength shift [nm] of M-cone.
:var_shft_S:
| 0, optional
| Std Dev. in peak wavelength shift [nm] of S-cone.
:out:
| 'LMS' or , optional
| Determines output.
:allow_negative_values:
| False, optional
| Cone fundamentals or color matching functions
should not have negative values.
| If False: X[X<0] = 0.
Returns:
:returns:
| - 'LMS' : ndarray with individual observer area-normalized
| cone fundamentals. Wavelength have been added.
| [- 'trans_lens': ndarray with lens transmission
| (no wavelengths added, no interpolation)
| - 'trans_macula': ndarray with macula transmission
| (no wavelengths added, no interpolation)
| - 'sens_photopig' : ndarray with photopigment sens.
| (no wavelengths added, no interpolation)]
References:
1. `Asano Y, Fairchild MD, and Blondé L (2016).
Individual Colorimetric Observer Model.
PLoS One 11, 1–19.
<http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0145671>`_
2. `Asano Y, Fairchild MD, Blondé L, and Morvan P (2016).
Color matching experiment for highlighting interobserver variability.
Color Res. Appl. 41, 530–539.
<https://onlinelibrary.wiley.com/doi/abs/10.1002/col.21975>`_
3. `CIE, and CIE (2006).
Fundamental Chromaticity Diagram with Physiological Axes - Part I
(Vienna: CIE).
<http://www.cie.co.at/publications/fundamental-chromaticity-diagram-physiological-axes-part-1>`_
4. `Asano's Individual Colorimetric Observer Model
<https://www.rit.edu/cos/colorscience/re_AsanoObserverFunctions.php>`_
"""
fs = fieldsize
rmd = _INDVCMF_DATA['rmd'].copy()
LMSa = _INDVCMF_DATA['LMSa'].copy()
docul = _INDVCMF_DATA['docul'].copy()
# field size corrected macular density:
pkOd_Macula = 0.485 * np.exp(-fs / 6.132) * (
1 + var_od_macula / 100) # varied peak optical density of macula
corrected_rmd = rmd * pkOd_Macula
# age corrected lens/ocular media density:
if (age <= 60):
correct_lomd = docul[:1] * (1 + 0.02 * (age - 32)) + docul[1:2]
else:
correct_lomd = docul[:1] * (1.56 + 0.0667 * (age - 60)) + docul[1:2]
correct_lomd = correct_lomd * (1 + var_od_lens / 100
) # varied overall optical density of lens
# Peak Wavelength Shift:
wl_shifted = np.empty(LMSa.shape)
wl_shifted[0] = _WL + var_shft_L
wl_shifted[1] = _WL + var_shft_M
wl_shifted[2] = _WL + var_shft_S
LMSa_shft = np.empty(LMSa.shape)
kind = 'cubic'
LMSa_shft[0] = interpolate.interp1d(wl_shifted[0],
LMSa[0],
kind=kind,
bounds_error=False,
fill_value="extrapolate")(_WL)
LMSa_shft[1] = interpolate.interp1d(wl_shifted[1],
LMSa[1],
kind=kind,
bounds_error=False,
fill_value="extrapolate")(_WL)
LMSa_shft[2] = interpolate.interp1d(wl_shifted[2],
LMSa[2],
kind=kind,
bounds_error=False,
fill_value="extrapolate")(_WL)
# LMSa[2,np.where(_WL >= _WL_CRIT)] = 0 #np.nan # Not defined above 620nm
# LMSa_shft[2,np.where(_WL >= _WL_CRIT)] = 0
ssw = np.hstack(
(0, np.sign(np.diff(LMSa_shft[2, :]))
)) #detect poor interpolation (sign switch due to instability)
LMSa_shft[2, np.where((ssw >= 0) & (_WL > 560))] = np.nan
# corrected LMS (no age correction):
pkOd_L = (0.38 + 0.54 * np.exp(-fs / 1.333)) * (
1 + var_od_L / 100) # varied peak optical density of L-cone
pkOd_M = (0.38 + 0.54 * np.exp(-fs / 1.333)) * (
1 + var_od_M / 100) # varied peak optical density of M-cone
pkOd_S = (0.30 + 0.45 * np.exp(-fs / 1.333)) * (
1 + var_od_S / 100) # varied peak optical density of S-cone
alpha_lms = 0. * LMSa_shft
alpha_lms[0] = 1 - 10**(-pkOd_L * (10**LMSa_shft[0]))
alpha_lms[1] = 1 - 10**(-pkOd_M * (10**LMSa_shft[1]))
alpha_lms[2] = 1 - 10**(-pkOd_S * (10**LMSa_shft[2]))
# this fix is required because the above math fails for alpha_lms[2,:]==0
alpha_lms[2, np.where(_WL >= _WL_CRIT)] = 0
# Corrected to Corneal Incidence:
lms_barq = alpha_lms * (10**(-corrected_rmd - correct_lomd)) * np.ones(
alpha_lms.shape)
# Corrected to Energy Terms:
lms_bar = lms_barq * _WL
# Set NaN values to zero:
lms_bar[np.isnan(lms_bar)] = 0
# normalized:
LMS = 100 * lms_bar / np.nansum(lms_bar, axis=1, keepdims=True)
# Output extra:
trans_lens = 10**(-correct_lomd)
trans_macula = 10**(-corrected_rmd)
sens_photopig = alpha_lms * _WL
# Add wavelengths:
LMS = np.vstack((_WL, LMS))
if ('xyz' in out.lower().split(',')):
LMS = lmsb_to_xyzb(LMS,
fieldsize,
out='xyz',
allow_negative_values=allow_negative_values)
out = out.replace('xyz', 'LMS').replace('XYZ', 'LMS')
if ('lms' in out.lower().split(',')):
out = out.replace('lms', 'LMS')
# Interpolate/extrapolate:
if wl is None:
interpolation = None
else:
interpolation = 'cubic'
LMS = spd(LMS, wl=wl, interpolation=interpolation, norm_type='area')
if (out == 'LMS'):
return LMS
elif (out == 'LMS,trans_lens,trans_macula,sens_photopig'):
return LMS, trans_lens, trans_macula, sens_photopig
elif (out == 'LMS,trans_lens,trans_macula,sens_photopig,LMSa'):
return LMS, trans_lens, trans_macula, sens_photopig, LMSa
else:
return eval(out)
def xyz_to_rfl(xyz, rfl = None, out = 'rfl_est', \
refspd = None, D = None, cieobs = _CIEOBS, \
cspace = 'xyz', cspace_tf = {},\
interp_type = 'nd', k_neighbours = 4, verbosity = 0):
"""
Approximate spectral reflectance of xyz based on nd-dimensional linear interpolation
or k nearest neighbour interpolation of samples from a standard reflectance set.
Args:
:xyz:
| ndarray with tristimulus values of target points.
:rfl:
| ndarray, optional
| Reflectance set for color coordinate to rfl mapping.
:out:
| 'rfl_est' or str, optional
:refspd:
| None, optional
| Refer ence spectrum for color coordinate to rfl mapping.
| None defaults to D65.
:cieobs:
| _CIEOBS, optional
| CMF set used for calculation of xyz from spectral data.
:cspace:
| 'xyz', optional
| Color space for color coordinate to rfl mapping.
| Tip: Use linear space (e.g. 'xyz', 'Yuv',...) for (interp_type == 'nd'),
| and perceptually uniform space (e.g. 'ipt') for (interp_type == 'nearest')
:cspace_tf:
| {}, optional
| Dict with parameters for xyz_to_cspace and cspace_to_xyz transform.
:interp_type:
| 'nd', optional
| Options:
| - 'nd': perform n-dimensional linear interpolation using Delaunay triangulation.
| - 'nearest': perform nearest neighbour interpolation.
:k_neighbours:
| 4 or int, optional
| Number of nearest neighbours for reflectance spectrum interpolation.
| Neighbours are found using scipy.cKDTree
:verbosity:
| 0, optional
| If > 0: make a plot of the color coordinates of original and
rendered image pixels.
Returns:
:returns:
| :rfl_est:
| ndarrays with estimated reflectance spectra.
"""
# get rfl set:
if rfl is None: # use IESTM30['4880'] set
rfl = _CRI_RFL['ies-tm30']['4880']['5nm']
# get Ref spd:
if refspd is None:
refspd = _CIE_ILLUMINANTS['D65'].copy()
# Calculate lab-type coordinates of standard rfl set under refspd:
xyz_rr, xyz_wr = spd_to_xyz(refspd,
relative=True,
rfl=rfl,
cieobs=cieobs,
out=2)
cspace_tf_copy = cspace_tf.copy()
cspace_tf_copy['xyzw'] = xyz_wr # put correct white point in param. dict
lab_rr = colortf(xyz_rr,
tf=cspace,
fwtf=cspace_tf_copy,
bwtf=cspace_tf_copy)[:, 0, :]
# Convert xyz to lab-type values under refspd:
lab = colortf(xyz, tf=cspace, fwtf=cspace_tf_copy, bwtf=cspace_tf_copy)
if interp_type == 'nearest':
# Find rfl (cfr. lab_rr) from rfl set that results in 'near' metameric
# color coordinates for each value in lab_ur (i.e. smallest DE):
# Construct cKDTree:
tree = cKDTree(lab_rr, copy_data=True)
# Interpolate rfls using k nearest neightbours and inverse distance weigthing:
d, inds = tree.query(lab, k=k_neighbours)
if k_neighbours > 1:
d += _EPS
w = (1.0 / d**2)[:, :, None] # inverse distance weigthing
rfl_est = np.sum(w * rfl[inds + 1, :], axis=1) / np.sum(w, axis=1)
else:
rfl_est = rfl[inds + 1, :].copy()
elif interp_type == 'nd':
rfl_est = math.ndinterp1_scipy(lab_rr, rfl[1:], lab)
_isnan = np.isnan(rfl_est[:, 0])
if (
_isnan.any()
): #do nearest neigbour method for those that fail using Delaunay (i.e. ndinterp1_scipy)
# Find rfl (cfr. lab_rr) from rfl set that results in 'near' metameric
# color coordinates for each value in lab_ur (i.e. smallest DE):
# Construct cKDTree:
tree = cKDTree(lab_rr, copy_data=True)
# Interpolate rfls using k nearest neightbours and inverse distance weigthing:
d, inds = tree.query(lab[_isnan, ...], k=k_neighbours)
if k_neighbours > 1:
d += _EPS
w = (1.0 / d**2)[:, :, None] # inverse distance weigthing
rfl_est_isnan = np.sum(w * rfl[inds + 1, :], axis=1) / np.sum(
w, axis=1)
else:
rfl_est_isnan = rfl[inds + 1, :].copy()
rfl_est[_isnan, :] = rfl_est_isnan
else:
raise Exception('xyz_to_rfl(): unsupported interp_type!')
rfl_est[
rfl_est <
0] = 0 #can occur for points outside convexhull of standard rfl set.
rfl_est = np.vstack((rfl[0], rfl_est))
if (verbosity > 0) | ('xyz_est' in out.split(',')) | (
'lab_est' in out.split(',')) | ('DEi_ab' in out.split(',')) | (
'DEa_ab' in out.split(',')):
xyz_est, _ = spd_to_xyz(refspd,
rfl=rfl_est,
relative=True,
cieobs=cieobs,
out=2)
cspace_tf_copy = cspace_tf.copy()
cspace_tf_copy[
'xyzw'] = xyz_wr # put correct white point in param. dict
lab_est = colortf(xyz_est, tf=cspace, fwtf=cspace_tf_copy)[:, 0, :]
DEi_ab = np.sqrt(((lab_est[:, 1:3] - lab[:, 1:3])**2).sum(axis=1))
DEa_ab = DEi_ab.mean()
if verbosity > 0:
ax = plot_color_data(lab[...,1], lab[...,2], z = lab[...,0], \
show = False, cieobs = cieobs, cspace = cspace, \
formatstr = 'ro', label = 'Original')
plot_color_data(lab_est[...,1], lab_est[...,2], z = lab_est[...,0], \
show = True, axh = ax, cieobs = cieobs, cspace = cspace, \
formatstr = 'bd', label = 'Rendered')
if out == 'rfl_est':
return rfl_est
elif out == 'rfl_est,xyz_est':
return rfl_est, xyz_est
else:
return eval(out)
def PX_colorshift_model(Jabt,
Jabr,
jab_ranges=None,
jab_deltas=None,
limit_grid_radius=0):
"""
Pixelates the color space and calculates the color shifts in each pixel.
Args:
:Jabt:
| ndarray with color coordinates under the (single) test SPD.
:Jabr:
| ndarray with color coordinates under the (single) reference SPD.
:jab_ranges:
| None or ndarray, optional
| Specifies the pixelization of color space.
| (ndarray.shape = (3,3), with first axis: J,a,b, and second
axis: min, max, delta)
:jab_deltas:
| float or ndarray, optional
| Specifies the sampling range.
| A float uses jab_deltas as the maximum Euclidean distance to select
samples around each pixel center. A ndarray of 3 deltas, uses
a city block sampling around each pixel center.
:limit_grid_radius:
| 0, optional
| A value of zeros keeps grid as specified by axr,bxr.
| A value > 0 only keeps (a,b) coordinates within :limit_grid_radius:
Returns:
:returns:
| dict with the following keys:
| - 'Jab': dict with with ndarrays for:
| Jabt, Jabr, DEi, DEi_ab (only ab-coordinates), DEa (mean)
| and DEa_ab
| - 'vshifts': dict with:
| * 'vectorshift': ndarray with vector shifts between average
| Jabt and Jabr for each pixel
| * 'vectorshift_ab': ndarray with vector shifts averaged
| over J for each pixel
| * 'vectorshift_ab_J0': ndarray with vector shifts averaged
| over J for each pixel of J=0 plane.
| * 'vectorshift_len': length of 'vectorshift'
| * 'vectorshift_ab_len': length of 'vectorshift_ab'
| * 'vectorshift_ab_J0_len': length of 'vectorshift_ab_J0'
| * 'vectorshift_len_DEnormed': length of 'vectorshift'
| normalized to 'DEa'
| * 'vectorshift_ab_len_DEnormed': length of 'vectorshift_ab'
| normalized to 'DEa_ab'
| * 'vectorshift_ab_J0_len_DEnormed': length of 'vectorshift_ab_J0'
| normalized to 'DEa_ab'
| - 'pixeldata': dict with pixel info:
| * 'grid' ndarray with coordinates of all pixel centers.
| * 'idx': list[int] with pixel index for each non-empty pixel
| * 'Jab': ndarray with center coordinates of non-empty pixels
| * 'samplenrs': list[list[int]] with sample numbers belong to
| each non-empty pixel
| * 'IDs: summarizing list,
| with column order: 'idxp, jabp, samplenrs'
| - 'fielddata' : dict with dicts containing data on the calculated
| vector-field and circle-fields
| * 'vectorfield': dict with ndarrays for the ab-coordinates
| under the ref. (axr, bxr) and test (axt, bxt) illuminants,
| centered at the pixel centers corresponding to the
ab-coordinates of the reference illuminant.
"""
# get pixelIDs of all samples under ref. conditions:
gridp, idxp, jabp, pixelsamplenrs, pixelIDs = get_pixel_coordinates(
Jabr,
jab_ranges=jab_ranges,
jab_deltas=jab_deltas,
limit_grid_radius=limit_grid_radius)
# get average Jab coordinates for each pixel:
Npixels = len(idxp) # number of non-empty pixels
Jabr_avg = np.nan * np.ones((gridp.shape[0], 3))
Jabt_avg = Jabr_avg.copy()
for i in range(Npixels):
Jabr_avg[idxp[i], :] = Jabr[pixelsamplenrs[i], :].mean(axis=0)
Jabt_avg[idxp[i], :] = Jabt[pixelsamplenrs[i], :].mean(axis=0)
#jabtemp = Jabr[pixelsamplenrs[i],:]
#jabtempm = Jabr_avg[idxp[i],:]
# calculate Jab vector shift:
vectorshift = Jabt_avg - Jabr_avg
# calculate ab vector shift:
uabs = gridp[gridp[:, 0] == 0, 1:3] #np.unique(gridp[:,1:3],axis=0)
vectorshift_ab_J0 = np.ones((uabs.shape[0], 2)) * np.nan
vectorshift_ab = np.ones((vectorshift.shape[0], 2)) * np.nan
for i in range(uabs.shape[0]):
cond = (gridp[:, 1:3] == uabs[i, :]).all(axis=1)
if cond.any() & np.logical_not(
np.isnan(vectorshift[cond, 1:3]).all()
): #last condition is to avoid warning of taking nanmean of empty slice when all are NaNs
vectorshift_ab_J0[i, :] = np.nanmean(vectorshift[cond, 1:3],
axis=0)
vectorshift_ab[cond, :] = np.nanmean(vectorshift[cond, 1:3],
axis=0)
# Calculate length of shift vectors:
vectorshift_len = np.sqrt((vectorshift**2).sum(axis=vectorshift.ndim - 1))
vectorshift_ab_len = np.sqrt(
(vectorshift_ab**2).sum(axis=vectorshift_ab.ndim - 1))
vectorshift_ab_J0_len = np.sqrt(
(vectorshift_ab_J0**2).sum(axis=vectorshift_ab_J0.ndim - 1))
# Calculate average DE for normalization of vectorshifts
DEi_Jab_avg = np.sqrt(((Jabt - Jabr)**2).sum(axis=Jabr.ndim - 1))
DE_Jab_avg = DEi_Jab_avg.mean(axis=0)
DEi_ab_avg = np.sqrt(
((Jabt[..., 1:3] - Jabr[..., 1:3])**2).sum(axis=Jabr[..., 1:3].ndim -
1))
DE_ab_avg = DEi_ab_avg.mean(axis=0)
# calculate vectorfield:
axr = uabs[:, 0, None]
bxr = uabs[:, 1, None]
axt = axr + vectorshift_ab_J0[:, 0, None]
bxt = bxr + vectorshift_ab_J0[:, 1, None]
data = {
'Jab': {
'Jabr': Jabr_avg,
'Jabt': Jabt_avg,
'DEi': DEi_Jab_avg,
'DEi_ab': DEi_ab_avg,
'DEa': DE_Jab_avg,
'DEa_ab': DE_ab_avg
},
'vshifts': {
'vectorshift': vectorshift,
'vectorshift_ab': vectorshift_ab,
'vectorshift_ab_J0': vectorshift_ab_J0,
'vectorshift_len': vectorshift_len,
'vectorshift_ab_len': vectorshift_ab_len,
'vectorshift_ab_J0_len': vectorshift_ab_J0_len,
'vectorshift_len_DEnormed': vectorshift_len / DE_Jab_avg,
'vectorshift_ab_len_DEnormed': vectorshift_ab_len / DE_ab_avg,
'vectorshift_ab_J0_len_DEnormed': vectorshift_ab_J0_len / DE_ab_avg
},
'pixeldata': {
'grid': gridp,
'idx': idxp,
'Jab': jabp,
'samplenrs': pixelsamplenrs,
'IDs': pixelIDs
},
'fielddata': {
'vectorfield': {
'axr': axr,
'bxr': bxr,
'axt': axt,
'bxt': bxt
}
}
}
return data
def plot_chromaticity_diagram_colors(diagram_samples = 256, diagram_opacity = 1.0, diagram_lightness = 0.25,\
cieobs = _CIEOBS, cspace = 'Yxy', cspace_pars = {},\
show = True, axh = None,\
show_grid = True, label_fontname = 'Times New Roman', label_fontsize = 12,\
**kwargs):
"""
Plot the chromaticity diagram colors.
Args:
:diagram_samples:
| 256, optional
| Sampling resolution of color space.
:diagram_opacity:
| 1.0, optional
| Sets opacity of chromaticity diagram
:diagram_lightness:
| 0.25, optional
| Sets lightness of chromaticity diagram
:axh:
| None or axes handle, optional
| Determines axes to plot data in.
| None: make new figure.
:show:
| True or False, optional
| Invoke matplotlib.pyplot.show() right after plotting
:cieobs:
| luxpy._CIEOBS or str, optional
| Determines CMF set to calculate spectrum locus or other.
:cspace:
| luxpy._CSPACE or str, optional
| Determines color space / chromaticity diagram to plot data in.
| Note that data is expected to be in specified :cspace:
:cspace_pars:
| {} or dict, optional
| Dict with parameters required by color space specified in :cspace:
| (for use with luxpy.colortf())
:show_grid:
| True, optional
| Show grid (True) or not (False)
:label_fontname:
| 'Times New Roman', optional
| Sets font type of axis labels.
:label_fontsize:
| 12, optional
| Sets font size of axis labels.
:kwargs:
| additional keyword arguments for use with matplotlib.pyplot.
Returns:
"""
offset = _EPS
ii, jj = np.meshgrid(np.linspace(offset, 1 + offset, diagram_samples), np.linspace(1+offset, offset, diagram_samples))
ij = np.dstack((ii, jj))
SL = _CMF[cieobs]['bar'][1:4].T
SL = np.vstack((SL,SL[0]))
SL = 100.0*SL/SL[:,1,None]
SL = colortf(SL, tf = cspace, tfa0 = cspace_pars)
Y,x,y = asplit(SL)
SL = np.vstack((x,y)).T
ij2D = ij.reshape((diagram_samples**2,2))
ij2D = np.hstack((diagram_lightness*100*np.ones((ij2D.shape[0],1)), ij2D))
xyz = colortf(ij2D, tf = cspace + '>xyz', tfa0 = cspace_pars)
xyz[xyz < 0] = 0
xyz[np.isinf(xyz.sum(axis=1)),:] = np.nan
xyz[np.isnan(xyz.sum(axis=1)),:] = offset
srgb = xyz_to_srgb(xyz)
srgb = srgb/srgb.max()
srgb = srgb.reshape((diagram_samples,diagram_samples,3))
if show == True:
if axh is None:
fig = plt.figure()
axh = fig.add_subplot(111)
polygon = Polygon(SL, facecolor='none', edgecolor='none')
axh.add_patch(polygon)
image = axh.imshow(
srgb,
interpolation='bilinear',
extent = (0.0, 1, -0.05, 1),
clip_path=None,
alpha=diagram_opacity)
image.set_clip_path(polygon)
plt.plot(x,y, color = 'darkgray')
if cspace == 'Yxy':
plt.xlim([0,1])
plt.ylim([0,1])
elif cspace == 'Yuv':
plt.xlim([0,0.6])
plt.ylim([0,0.6])
if (cspace is not None):
xlabel = _CSPACE_AXES[cspace][1]
ylabel = _CSPACE_AXES[cspace][2]
if (label_fontname is not None) & (label_fontsize is not None):
plt.xlabel(xlabel, fontname = label_fontname, fontsize = label_fontsize)
plt.ylabel(ylabel, fontname = label_fontname, fontsize = label_fontsize)
if show_grid == True:
plt.grid()
#plt.show()
return axh
else:
return None
