def normalize_to_Lw(Ill, Lw, cieobs, rflM):
xyzw = lx.spd_to_xyz(Ill, cieobs=cieobs, relative=False)
for i in range(Ill.shape[0] - 1):
Ill[i + 1] = Lw * Ill[i + 1] / xyzw[i, 1]
IllM = []
for i in range(Ill.shape[0] - 1):
IllM.append(np.vstack((Ill1[0], Ill[i + 1] * rflM[1:, :])))
IllM = np.transpose(np.array(IllM), (1, 0, 2))
return Ill, IllM
def _massage_output_data_to_original_shape(camout, originalshape):
"""
Massage output data to restore original shape of input.
"""
# Flip light source dim back to axis 1:
camout = np.transpose(camout, axes=(1, 0, 2))
if len(originalshape) < 3:
if camout.shape[1] == 1:
camout = np.squeeze(camout, axis=1)
return camout
def join(self, data):
"""
Join data along last axis and return instance.
"""
if data[0].ndim == 2: #faster implementation
self.value = np.transpose(
np.concatenate(data, axis=0).reshape((np.hstack(
(len(data), data[0].shape)))), (1, 2, 0))
elif data[0].ndim == 1:
self.value = np.concatenate(data, axis=0).reshape((np.hstack(
(len(data), data[0].shape)))).T
else:
self.value = np.hstack(data)[0]
return self
def _massage_output_data_to_original_shape(data, originalshape):
"""
Massage output data to restore original shape of original CAM input.
Notes:
For an example on the use, see code _simple_cam() (type: _simple_cam??)
"""
# Flip light source dim back to axis 1:
data = np.transpose(data, axes=(1, 0, 2))
if len(originalshape) < 3:
if data.shape[1] == 1:
data = np.squeeze(data, axis=1)
return data
def ndset(F):
"""
Finds the nondominated set of a set of objective points.
Args:
:F:
| a m x mu ndarray with mu points and m objectives
Returns:
:ispar:
| a mu-length vector with true in the nondominated points
"""
mu = F.shape[1] #number of points
# The idea is to compare each point with the other ones
f1 = np.transpose(F[...,None], axes = [0, 2, 1]) #puts in the 3D direction
f1 = np.repeat(f1,mu,axis=1)
f2 = np.repeat(F[...,None],mu,axis=2)
# Now, for the ii-th slice, the ii-th individual is compared with all of the
# others at once. Then, the usual operations of domination are checked
# Checks where f1 dominates f2
aux1 = (f1 <= f2).all(axis = 0, keepdims = True)
aux2 = (f1 < f2).any(axis = 0, keepdims = True)
auxf1 = np.logical_and(aux1, aux2)
# Checks where f1 is dominated by f2
aux1 = (f1 >= f2).all(axis = 0, keepdims = True)
aux2 = (f1 > f2).any(axis = 0, keepdims = True)
auxf2 = np.logical_and(aux1, aux2)
# dom will be a 3D matrix (1 x mu x mu) such that, for the ii-th slice, it
# will contain +1 if fii dominates the current point, -1 if it is dominated
# by it, and 0 if they are incomparable
dom = np.zeros((1, mu, mu), dtype = int)
dom[auxf1] = 1
dom[auxf2] = -1
# Finally, the slices with no -1 are nondominated
ispar = (dom != -1).all(axis = 1)
ispar = ispar.flatten()
return ispar
def _cij_to_gij(xyz,C):
""" Convert from matrix elements describing the discrimination ellipses from Cij (XYZ) to gij (Yxy)"""
SIG = xyz[...,0] + xyz[...,1] + xyz[...,2]
M1 = np.array([SIG, -SIG*xyz[...,0]/xyz[...,1], xyz[...,0]/xyz[...,1]])
M2 = np.array([np.zeros_like(SIG), np.zeros_like(SIG), np.ones_like(SIG)])
M3 = np.array([-SIG, -SIG*(xyz[...,1] + xyz[...,2])/xyz[...,1], xyz[...,2]/xyz[...,1]])
M = np.array((M1,M2,M3))
M = _transpose_02(M) # move stimulus dimension to axis = 0
C = _transpose_02(C) # move stimulus dimension to axis = 0
# convert Cij (XYZ) to gij' (xyY):
AM = np.einsum('ij,kjl->kil', _M_XYZ_TO_PQS, M)
CAM = np.einsum('kij,kjl->kil', C, AM)
# ATCAM = np.einsum('ij,kjl->kil', _M_XYZ_TO_PQS.T, CAM)
# gij = np.einsum('kij,kjl->kil', np.transpose(M,(0,2,1)), ATCAM) # gij = M.T*A.T*C**A*M = (AM).T*C*A*M
gij = np.einsum('kij,kjl->kil', np.transpose(AM,(0,2,1)), CAM) # gij = M.T*A.T*C**A*M = (AM).T*C*A*M
# convert gij' (xyY) to gij (Yxy):
gij = np.roll(np.roll(gij,1,axis=2),1,axis=1)
return gij
def _massage_input_and_init_output(data,
dataw,
inputtype='xyz',
direction='forward',
n_out=3):
"""
Redimension input data to ensure most they have the appropriate sizes for easy and efficient looping.
|
| 1. Convert data and dataw to atleast_2d ndarrays
| 2. Make axis 1 of dataw have 'same' dimensions as data
| 3. Make dataw have same lights source axis size as data
| 4. Flip light source axis to axis=0 for efficient looping
| 5. Initialize output array camout to 'same' shape as data but with camout.shape[-1] == n_out
Args:
:data:
| ndarray with input tristimulus values
| or spectral data
| or input color appearance correlates
| Can be of shape: (N [, xM], x 3), whereby:
| N refers to samples and M refers to light sources.
| Note that for spectral input shape is (N x (M+1) x wl)
:dataw:
| None or ndarray, optional
| Input tristimulus values or spectral data of white point.
| None defaults to the use of CIE illuminant C.
:inputtype:
| 'xyz' or 'spd', optional
| Specifies the type of input:
| tristimulus values or spectral data for the forward mode.
:direction:
| 'forward' or 'inverse', optional
| -'forward': xyz -> cam
| -'inverse': cam -> xyz
:n_out:
| 3, optional
| output size of last dimension of camout
| (e.g. n_out=3 for j,a,b output or n_out = 5 for J,M,h,a,b output)
Returns:
:data:
| ndarray with reshaped data
:dataw:
| ndarray with reshaped dataw
:camout:
| NaN filled ndarray for output of CAMv (camout.shape[-1] == Nout)
:originalshape:
| original shape of data
Notes:
For an example on the use, see code _simple_cam() (type: _simple_cam??)
"""
# Convert data and dataw to atleast_2d ndarrays:
data = np2d(data).copy(
) # stimulus data (can be upto NxMx3 for xyz, or [N x (M+1) x wl] for spd))
dataw = np2d(dataw).copy(
) # white point (can be upto Nx3 for xyz, or [(N+1) x wl] for spd)
originalshape = data.shape # to restore output to same shape
# Make axis 1 of dataw have 'same' dimensions as data:
if (data.ndim == 2):
data = np.expand_dims(data, axis=1) # add light source axis 1
# Flip light source dim to axis 0:
data = np.transpose(data, axes=(1, 0, 2))
dataw = np.expand_dims(
dataw, axis=1) # add extra axis to move light source to axis 0
# Make dataw have same lights source dimension size as data:
if inputtype == 'xyz':
if dataw.shape[0] == 1:
dataw = np.repeat(dataw, data.shape[0], axis=0)
if (data.shape[0] == 1) & (dataw.shape[0] > 1):
data = np.repeat(data, dataw.shape[0], axis=0)
else:
dataw = np.array([
np.vstack((dataw[:1, 0, :], dataw[i + 1:i + 2, 0, :]))
for i in range(dataw.shape[0] - 1)
])
if (data.shape[0] == 1) & (dataw.shape[0] > 1):
data = np.repeat(data, dataw.shape[0], axis=0)
# Initialize output array:
if n_out is not None:
dshape = list((data).shape)
dshape[-1] = n_out # requested number of correlates: e.g. j,a,b
if (inputtype != 'xyz') & (direction == 'forward'):
dshape[-2] = dshape[
-2] - 1 # wavelength row doesn't count & only with forward can the input data be spectral
camout = np.zeros(dshape)
camout.fill(np.nan)
else:
camout = None
return data, dataw, camout, originalshape
def plotellipse(v, cspace_in = 'Yxy', cspace_out = None, nsamples = 100, \
show = True, axh = None, \
line_color = 'darkgray', line_style = ':', line_width = 1, line_marker = '', line_markersize = 4,\
plot_center = False, center_marker = 'o', center_color = 'darkgray', center_markersize = 4,\
show_grid = False, llabel = '', label_fontname = 'Times New Roman', label_fontsize = 12,\
out = None):
"""
Plot ellipse(s) given in v-format [Rmax,Rmin,xc,yc,theta].
Args:
:v:
| (Nx5) ndarray
| ellipse parameters [Rmax,Rmin,xc,yc,theta]
:cspace_in:
| 'Yxy', optional
| Color space of v.
| If None: no color space assumed. Axis labels assumed ('x','y').
:cspace_out:
| None, optional
| Color space to plot ellipse(s) in.
| If None: plot in cspace_in.
:nsamples:
| 100 or int, optional
| Number of points (samples) in ellipse boundary
:show:
| True or boolean, optional
| Plot ellipse(s) (True) or not (False)
:axh:
| None, optional
| Ax-handle to plot ellipse(s) in.
| If None: create new figure with axes.
:line_color:
| 'darkgray', optional
| Color to plot ellipse(s) in.
:line_style:
| ':', optional
| Linestyle of ellipse(s).
:line_width':
| 1, optional
| Width of ellipse boundary line.
:line_marker:
| 'none', optional
| Marker for ellipse boundary.
:line_markersize:
| 4, optional
| Size of markers in ellipse boundary.
:plot_center:
| False, optional
| Plot center of ellipse: yes (True) or no (False)
:center_color:
| 'darkgray', optional
| Color to plot ellipse center in.
:center_marker:
| 'o', optional
| Marker for ellipse center.
:center_markersize:
| 4, optional
| Size of marker of ellipse center.
:show_grid:
| False, optional
| Show grid (True) or not (False)
:llabel:
| None,optional
| Legend label for ellipse boundary.
:label_fontname:
| 'Times New Roman', optional
| Sets font type of axis labels.
:label_fontsize:
| 12, optional
| Sets font size of axis labels.
:out:
| None, optional
| Output of function
| If None: returns None. Can be used to output axh of newly created
| figure axes or to return Yxys an ndarray with coordinates of
| ellipse boundaries in cspace_out (shape = (nsamples,3,N))
Returns:
:returns: None, or whatever set by :out:.
"""
Yxys = np.zeros((nsamples, 3, v.shape[0]))
ellipse_vs = np.zeros((v.shape[0], 5))
for i, vi in enumerate(v):
# Set sample density of ellipse boundary:
t = np.linspace(0, 2 * np.pi, int(nsamples))
a = vi[0] # major axis
b = vi[1] # minor axis
xyc = vi[2:4, None] # center
theta = vi[-1] # rotation angle
# define rotation matrix:
R = np.hstack((np.vstack((np.cos(theta), np.sin(theta))),
np.vstack((-np.sin(theta), np.cos(theta)))))
# Calculate ellipses:
Yxyc = np.vstack((1, xyc)).T
Yxy = np.vstack(
(np.ones((1, nsamples)),
xyc + np.dot(R, np.vstack((a * np.cos(t), b * np.sin(t)))))).T
Yxys[:, :, i] = Yxy
# Convert to requested color space:
if (cspace_out is not None) & (cspace_in is not None):
Yxy = colortf(Yxy, cspace_in + '>' + cspace_out)
Yxyc = colortf(Yxyc, cspace_in + '>' + cspace_out)
Yxys[:, :, i] = Yxy
# get ellipse parameters in requested color space:
ellipse_vs[i, :] = math.fit_ellipse(Yxy[:, 1:])
#de = np.sqrt((Yxy[:,1]-Yxyc[:,1])**2 + (Yxy[:,2]-Yxyc[:,2])**2)
#ellipse_vs[i,:] = np.hstack((de.max(),de.min(),Yxyc[:,1],Yxyc[:,2],np.nan)) # nan because orientation is xy, but request is some other color space. Change later to actual angle when fitellipse() has been implemented
# plot ellipses:
if show == True:
if (axh is None) & (i == 0):
fig = plt.figure()
axh = fig.add_subplot(111)
if (cspace_in is None):
xlabel = 'x'
ylabel = 'y'
else:
xlabel = _CSPACE_AXES[cspace_in][1]
ylabel = _CSPACE_AXES[cspace_in][2]
if (cspace_out is not None):
xlabel = _CSPACE_AXES[cspace_out][1]
ylabel = _CSPACE_AXES[cspace_out][2]
if plot_center == True:
axh.plot(Yxyc[:, 1],
Yxyc[:, 2],
color=center_color,
linestyle='none',
marker=center_marker,
markersize=center_markersize)
if llabel is None:
axh.plot(Yxy[:, 1],
Yxy[:, 2],
color=line_color,
linestyle=line_style,
linewidth=line_width,
marker=line_marker,
markersize=line_markersize)
else:
axh.plot(Yxy[:, 1],
Yxy[:, 2],
color=line_color,
linestyle=line_style,
linewidth=line_width,
marker=line_marker,
markersize=line_markersize,
label=llabel)
axh.set_xlabel(xlabel,
fontname=label_fontname,
fontsize=label_fontsize)
axh.set_ylabel(ylabel,
fontname=label_fontname,
fontsize=label_fontsize)
if show_grid == True:
plt.grid(True)
#plt.show()
Yxys = np.transpose(Yxys, axes=(0, 2, 1))
if out is not None:
return eval(out)
else:
return None
def VF_colorshift_model(S, cri_type = _VF_CRI_DEFAULT, model_type = _VF_MODEL_TYPE, \
cspace = _VF_CSPACE, sampleset = None, pool = False, \
pcolorshift = {'href': np.arange(np.pi/10,2*np.pi,2*np.pi/10),'Cref' : _VF_MAXR, 'sig' : _VF_SIG}, \
vfcolor = 'k',verbosity = 0):
"""
Applies full vector field model calculations to spectral data.
Args:
:S:
| nump.ndarray with spectral data.
:cri_type:
| _VF_CRI_DEFAULT or str or dict, optional
| Specifies type of color fidelity model to use.
| Controls choice of ref. ill., sample set, averaging, scaling, etc.
| See luxpy.cri.spd_to_cri for more info.
:modeltype:
| _VF_MODEL_TYPE or 'M6' or 'M5', optional
| Specifies degree 5 or degree 6 polynomial model in ab-coordinates.
:cspace:
| _VF_CSPACE or dict, optional
| Specifies color space. See _VF_CSPACE_EXAMPLE for example structure.
:sampleset:
| None or str or ndarray, optional
| Sampleset to be used when calculating vector field model.
:pool:
| False, optional
| If :S: contains multiple spectra, True pools all jab data before
| modeling the vector field, while False models a different field
| for each spectrum.
:pcolorshift:
| default dict (see below) or user defined dict, optional
| Dict containing the specification input
| for apply_poly_model_at_hue_x().
| Default dict = {'href': np.arange(np.pi/10,2*np.pi,2*np.pi/10),
| 'Cref' : _VF_MAXR,
| 'sig' : _VF_SIG,
| 'labels' : '#'}
| The polynomial models of degree 5 and 6 can be fully specified or
| summarized by the model parameters themselved OR by calculating the
| dCoverC and dH at resp. 5 and 6 hues.
:vfcolor:
| 'k', optional
| For plotting the vector fields.
:verbosity:
| 0, optional
| Report warnings or not.
Returns:
:returns:
| list[dict] (each list element refers to a different test SPD)
| with the following keys:
| - 'Source': dict with ndarrays of the S, cct and duv of source spd.
| - 'metrics': dict with ndarrays for:
| * Rf (color fidelity: base + metameric shift)
| * Rt (metameric uncertainty index)
| * Rfi (specific color fidelity indices)
| * Rti (specific metameric uncertainty indices)
| * cri_type (str with cri_type)
| - 'Jab': dict with with ndarrays for Jabt, Jabr, DEi
| - 'dC/C_dH_x_sig' :
| np.vstack((dCoverC_x,dCoverC_x_sig,dH_x,dH_x_sig)).T
| See get_poly_model() for more info.
| - 'fielddata': dict with dicts containing data on the calculated
| vector-field and circle-fields:
| * 'vectorfield' : {'axt': vfaxt, 'bxt' : vfbxt,
| 'axr' : vfaxr, 'bxr' : vfbxr},
| * 'circlefield' : {'axt': cfaxt, 'bxt' : cfbxt,
| 'axr' : cfaxr, 'bxr' : cfbxr}},
| - 'modeldata' : dict with model info:
| {'pmodel': pmodel,
| 'pcolorshift' : pcolorshift,
| 'dab_model' : dab_model,
| 'dab_res' : dab_res,
| 'dab_std' : dab_std,
| 'modeltype' : modeltype,
| 'fmodel' : poly_model,
| 'Jabtm' : Jabtm,
| 'Jabrm' : Jabrm,
| 'DEim' : DEim},
| - 'vshifts' :dict with various vector shifts:
| * 'Jabshiftvector_r_to_t' : ndarray with difference vectors
| between jabt and jabr.
| * 'vshift_ab_s' : vshift_ab_s: ab-shift vectors of samples
| * 'vshift_ab_s_vf' : vshift_ab_s_vf: ab-shift vectors of
| VF model predictions of samples.
| * 'vshift_ab_vf' : vshift_ab_vf: ab-shift vectors of VF
| model predictions of vector field grid.
"""
if type(cri_type) == str:
cri_type_str = cri_type
else:
cri_type_str = None
# Calculate Rf, Rfi and Jabr, Jabt:
Rf, Rfi, Jabt, Jabr, cct, duv, cri_type = spd_to_cri(
S,
cri_type=cri_type,
out='Rf,Rfi,jabt,jabr,cct,duv,cri_type',
sampleset=sampleset)
# In case of multiple source SPDs, pool:
if (len(Jabr.shape) == 3) & (Jabr.shape[1] > 1) & (pool == True):
#Nsamples = Jabr.shape[0]
Jabr = np.transpose(Jabr, (1, 0, 2)) # set lamps on first dimension
Jabt = np.transpose(Jabt, (1, 0, 2))
Jabr = Jabr.reshape(Jabr.shape[0] * Jabr.shape[1],
3) # put all lamp data one after the other
Jabt = Jabt.reshape(Jabt.shape[0] * Jabt.shape[1], 3)
Jabt = Jabt[:, None, :] # add dim = 1
Jabr = Jabr[:, None, :]
out = [{} for _ in range(Jabr.shape[1])] #initialize empty list of dicts
if pool == False:
N = Jabr.shape[1]
else:
N = 1
for i in range(N):
Jabr_i = Jabr[:, i, :].copy()
Jabr_i = Jabr_i[:, None, :]
Jabt_i = Jabt[:, i, :].copy()
Jabt_i = Jabt_i[:, None, :]
DEi = np.sqrt((Jabr_i[..., 0] - Jabt_i[..., 0])**2 +
(Jabr_i[..., 1] - Jabt_i[..., 1])**2 +
(Jabr_i[..., 2] - Jabt_i[..., 2])**2)
# Determine polynomial model:
poly_model, pmodel, dab_model, dab_res, dCHoverC_res, dab_std, dCHoverC_std = get_poly_model(
Jabt_i, Jabr_i, modeltype=_VF_MODEL_TYPE)
# Apply model at fixed hues:
href = pcolorshift['href']
Cref = pcolorshift['Cref']
sig = pcolorshift['sig']
dCoverC_x, dCoverC_x_sig, dH_x, dH_x_sig = apply_poly_model_at_hue_x(
poly_model, pmodel, dCHoverC_res, hx=href, Cxr=Cref, sig=sig)
# Calculate deshifted a,b values on original samples:
Jt = Jabt_i[..., 0].copy()
at = Jabt_i[..., 1].copy()
bt = Jabt_i[..., 2].copy()
Jr = Jabr_i[..., 0].copy()
ar = Jabr_i[..., 1].copy()
br = Jabr_i[..., 2].copy()
ar = ar + dab_model[:, 0:1] # deshift reference to model prediction
br = br + dab_model[:, 1:2] # deshift reference to model prediction
Jabtm = np.hstack((Jt, at, bt))
Jabrm = np.hstack((Jr, ar, br))
# calculate color differences between test and deshifted ref:
# DEim = np.sqrt((Jr - Jt)**2 + (at - ar)**2 + (bt - br)**2)
DEim = np.sqrt(0 * (Jr - Jt)**2 + (at - ar)**2 +
(bt - br)**2) # J is not used
# Apply scaling function to convert DEim to Rti:
scale_factor = cri_type['scale']['cfactor']
scale_fcn = cri_type['scale']['fcn']
avg = cri_type['avg']
Rfi_deshifted = scale_fcn(DEim, scale_factor)
Rf_deshifted = scale_fcn(avg(DEim, axis=0), scale_factor)
rms = lambda x: np.sqrt(np.sum(x**2, axis=0) / x.shape[0])
Rf_deshifted_rms = scale_fcn(rms(DEim), scale_factor)
# Generate vector field:
vfaxt, vfbxt, vfaxr, vfbxr = generate_vector_field(
poly_model,
pmodel,
axr=np.arange(-_VF_MAXR, _VF_MAXR + _VF_DELTAR, _VF_DELTAR),
bxr=np.arange(-_VF_MAXR, _VF_MAXR + _VF_DELTAR, _VF_DELTAR),
limit_grid_radius=_VF_MAXR,
color=0)
vfaxt, vfbxt, vfaxr, vfbxr = generate_vector_field(
poly_model,
pmodel,
axr=np.arange(-_VF_MAXR, _VF_MAXR + _VF_DELTAR, _VF_DELTAR),
bxr=np.arange(-_VF_MAXR, _VF_MAXR + _VF_DELTAR, _VF_DELTAR),
limit_grid_radius=_VF_MAXR,
color=0)
# Calculate ab-shift vectors of samples and VF model predictions:
vshift_ab_s = calculate_shiftvectors(Jabt_i,
Jabr_i,
average=False,
vtype='ab')[:, 0, 0:3]
vshift_ab_s_vf = calculate_shiftvectors(Jabtm,
Jabrm,
average=False,
vtype='ab')
# Calculate ab-shift vectors using vector field model:
Jabt_vf = np.hstack((np.zeros((vfaxt.shape[0], 1)), vfaxt, vfbxt))
Jabr_vf = np.hstack((np.zeros((vfaxr.shape[0], 1)), vfaxr, vfbxr))
vshift_ab_vf = calculate_shiftvectors(Jabt_vf,
Jabr_vf,
average=False,
vtype='ab')
# Generate circle field:
x, y = plotcircle(radii=np.arange(0, _VF_MAXR + _VF_DELTAR, 10),
angles=np.arange(0, 359, 1),
out='x,y')
cfaxt, cfbxt, cfaxr, cfbxr = generate_vector_field(
poly_model,
pmodel,
make_grid=False,
axr=x[:, None],
bxr=y[:, None],
limit_grid_radius=_VF_MAXR,
color=0)
out[i] = {
'Source': {
'S': S,
'cct': cct[i],
'duv': duv[i]
},
'metrics': {
'Rf': Rf[:, i],
'Rt': Rf_deshifted,
'Rt_rms': Rf_deshifted_rms,
'Rfi': Rfi[:, i],
'Rti': Rfi_deshifted,
'cri_type': cri_type_str
},
'Jab': {
'Jabt': Jabt_i,
'Jabr': Jabr_i,
'DEi': DEi
},
'dC/C_dH_x_sig':
np.vstack((dCoverC_x, dCoverC_x_sig, dH_x, dH_x_sig)).T,
'fielddata': {
'vectorfield': {
'axt': vfaxt,
'bxt': vfbxt,
'axr': vfaxr,
'bxr': vfbxr
},
'circlefield': {
'axt': cfaxt,
'bxt': cfbxt,
'axr': cfaxr,
'bxr': cfbxr
}
},
'modeldata': {
'pmodel': pmodel,
'pcolorshift': pcolorshift,
'dab_model': dab_model,
'dab_res': dab_res,
'dab_std': dab_std,
'model_type': model_type,
'fmodel': poly_model,
'Jabtm': Jabtm,
'Jabrm': Jabrm,
'DEim': DEim
},
'vshifts': {
'Jabshiftvector_r_to_t': np.hstack(
(Jt - Jr, at - ar, bt - br)),
'vshift_ab_s': vshift_ab_s,
'vshift_ab_s_vf': vshift_ab_s_vf,
'vshift_ab_vf': vshift_ab_vf
}
}
return out
def _transpose_02(C):
if C.ndim == 3:
C = np.transpose(C,(2,0,1))
else:
C = C[None,...]
return C
def cam15u(data,
fov=10.0,
inputtype='xyz',
direction='forward',
outin='Q,aW,bW',
parameters=None):
"""
Convert between CIE 2006 10° XYZ tristimulus values (or spectral data)
and CAM15u color appearance correlates.
Args:
:data:
| ndarray of CIE 2006 10° XYZ tristimulus values or spectral data
| or color appearance attributes
:fov:
| 10.0, optional
| Field-of-view of stimulus (for size effect on brightness)
:inputtpe:
| 'xyz' or 'spd', optional
| Specifies the type of input:
| tristimulus values or spectral data for the forward mode.
:direction:
| 'forward' or 'inverse', optional
| -'forward': xyz -> cam15u
| -'inverse': cam15u -> xyz
:outin:
| 'Q,aW,bW' or str, optional
| 'Q,aW,bW' (brightness and opponent signals for amount-of-neutral)
| other options: 'Q,aM,bM' (colorfulness) and 'Q,aS,bS' (saturation)
| Str specifying the type of
| input (:direction: == 'inverse') and
| output (:direction: == 'forward')
:parameters:
| None or dict, optional
| Set of model parameters.
| - None: defaults to luxpy.cam._CAM15U_PARAMETERS
| (see references below)
Returns:
:returns:
| ndarray with color appearance correlates (:direction: == 'forward')
| or
| XYZ tristimulus values (:direction: == 'inverse')
References:
1. `M. Withouck, K. A. G. Smet, W. R. Ryckaert, and P. Hanselaer,
“Experimental driven modelling of the color appearance of
unrelated self-luminous stimuli: CAM15u,”
Opt. Express, vol. 23, no. 9, pp. 12045–12064, 2015.
<https://www.osapublishing.org/oe/abstract.cfm?uri=oe-23-9-12045&origin=search>`_
2. `M. Withouck, K. A. G. Smet, and P. Hanselaer, (2015),
“Brightness prediction of different sized unrelated self-luminous stimuli,”
Opt. Express, vol. 23, no. 10, pp. 13455–13466.
<https://www.osapublishing.org/oe/abstract.cfm?uri=oe-23-10-13455&origin=search>`_
"""
if parameters is None:
parameters = _CAM15U_PARAMETERS
outin = outin.split(',')
#unpack model parameters:
Mxyz2rgb, cA, cAlms, cHK, cM, cW, ca, calms, cb, cblms, cfov, cp, k, unique_hue_data = [
parameters[x] for x in sorted(parameters.keys())
]
# precomputations:
invMxyz2rgb = np.linalg.inv(Mxyz2rgb)
MAab = np.array([cAlms, calms, cblms])
invMAab = np.linalg.inv(MAab)
#initialize data and camout:
data = np2d(data)
if len(data.shape) == 2:
data = np.expand_dims(data, axis=0) # avoid looping if not necessary
if (data.shape[0] > data.shape[1]): # loop over shortest dim.
flipaxis0and1 = True
data = np.transpose(data, axes=(1, 0, 2))
else:
flipaxis0and1 = False
dshape = list(data.shape)
dshape[-1] = len(outin) # requested number of correlates
if (inputtype != 'xyz') & (direction == 'forward'):
dshape[-2] = dshape[
-2] - 1 # wavelength row doesn't count & only with forward can the input data be spectral
camout = np.zeros(dshape)
camout.fill(np.nan)
for i in range(data.shape[0]):
if (inputtype != 'xyz') & (direction == 'forward'):
xyz = spd_to_xyz(data[i], cieobs='2006_10', relative=False)
lms = np.dot(_CMF['2006_10']['M'], xyz.T).T # convert to l,m,s
rgb = (lms /
_CMF['2006_10']['K']) * k # convert to rho, gamma, beta
elif (inputtype == 'xyz') & (direction == 'forward'):
rgb = np.dot(Mxyz2rgb, data[i].T).T
if direction == 'forward':
# apply cube-root compression:
rgbc = rgb**(cp)
# calculate achromatic and color difference signals, A, a, b:
Aab = np.dot(MAab, rgbc.T).T
A, a, b = asplit(Aab)
A = cA * A
a = ca * a
b = cb * b
# calculate colorfullness like signal M:
M = cM * ((a**2.0 + b**2.0)**0.5)
# calculate brightness Q:
Q = A + cHK[0] * M**cHK[
1] # last term is contribution of Helmholtz-Kohlrausch effect on brightness
# calculate saturation, s:
s = M / Q
# calculate amount of white, W:
W = 100.0 / (1.0 + cW[0] * (s**cW[1]))
# adjust Q for size (fov) of stimulus (matter of debate whether to do this before or after calculation of s or W, there was no data on s, M or W for different sized stimuli: after)
Q = Q * (fov / 10.0)**cfov
# calculate hue, h and Hue quadrature, H:
h = hue_angle(a, b, htype='deg')
if 'H' in outin:
H = hue_quadrature(h, unique_hue_data=unique_hue_data)
else:
H = None
# calculate cart. co.:
if 'aM' in outin:
aM = M * np.cos(h * np.pi / 180.0)
bM = M * np.sin(h * np.pi / 180.0)
if 'aS' in outin:
aS = s * np.cos(h * np.pi / 180.0)
bS = s * np.sin(h * np.pi / 180.0)
if 'aW' in outin:
aW = W * np.cos(h * np.pi / 180.0)
bW = W * np.sin(h * np.pi / 180.0)
if (outin != ['Q', 'aW', 'bW']):
camout[i] = eval('ajoin((' + ','.join(outin) + '))')
else:
camout[i] = ajoin((Q, aW, bW))
elif direction == 'inverse':
# get Q, M and a, b depending on input type:
if 'aW' in outin:
Q, a, b = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
W = (a**2.0 + b**2.0)**0.5
s = (((100 / W) - 1.0) / cW[0])**(1.0 / cW[1])
M = s * Q
if 'aM' in outin:
Q, a, b = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
M = (a**2.0 + b**2.0)**0.5
if 'aS' in outin:
Q, a, b = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
s = (a**2.0 + b**2.0)**0.5
M = s * Q
if 'h' in outin:
Q, WsM, h = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
if 'W' in outin:
s = (((100.0 / WsM) - 1.0) / cW[0])**(1.0 / cW[1])
M = s * Q
elif 's' in outin:
M = WsM * Q
elif 'M' in outin:
M = WsM
# calculate achromatic signal, A from Q and M:
A = Q - cHK[0] * M**cHK[1]
A = A / cA
# calculate hue angle:
h = hue_angle(a, b, htype='rad')
# calculate a,b from M and h:
a = (M / cM) * np.cos(h)
b = (M / cM) * np.sin(h)
a = a / ca
b = b / cb
# create Aab:
Aab = ajoin((A, a, b))
# calculate rgbc:
rgbc = np.dot(invMAab, Aab.T).T
# decompress rgbc to rgb:
rgb = rgbc**(1 / cp)
# convert rgb to xyz:
xyz = np.dot(invMxyz2rgb, rgb.T).T
camout[i] = xyz
if flipaxis0and1 == True: # loop over shortest dim.
camout = np.transpose(camout, axes=(1, 0, 2))
if camout.shape[0] == 1:
camout = np.squeeze(camout, axis=0)
return camout
def cam_sww16(data, dataw = None, Yb = 20.0, Lw = 400.0, Ccwb = None, relative = True, \
parameters = None, inputtype = 'xyz', direction = 'forward', \
cieobs = '2006_10'):
"""
A simple principled color appearance model based on a mapping
of the Munsell color system.
| This function implements the JOSA A (parameters = 'JOSA') published model.
Args:
:data:
| ndarray with input tristimulus values
| or spectral data
| or input color appearance correlates
| Can be of shape: (N [, xM], x 3), whereby:
| N refers to samples and M refers to light sources.
| Note that for spectral input shape is (N x (M+1) x wl)
:dataw:
| None or ndarray, optional
| Input tristimulus values or spectral data of white point.
| None defaults to the use of CIE illuminant C.
:Yb:
| 20.0, optional
| Luminance factor of background (perfect white diffuser, Yw = 100)
:Lw:
| 400.0, optional
| Luminance (cd/m²) of white point.
:Ccwb:
| None, optional
| Degree of cognitive adaptation (white point balancing)
| If None: use [..,..] from parameters dict.
:relative:
| True or False, optional
| True: xyz tristimulus values are relative (Yw = 100)
:parameters:
| None or str or dict, optional
| Dict with model parameters.
| - None: defaults to luxpy.cam._CAM_SWW_2016_PARAMETERS['JOSA']
| - str: 'best-fit-JOSA' or 'best-fit-all-Munsell'
| - dict: user defined model parameters
| (dict should have same structure)
:inputtype:
| 'xyz' or 'spd', optional
| Specifies the type of input:
| tristimulus values or spectral data for the forward mode.
:direction:
| 'forward' or 'inverse', optional
| -'forward': xyz -> cam_sww_2016
| -'inverse': cam_sww_2016 -> xyz
:cieobs:
| '2006_10', optional
| CMF set to use to perform calculations where spectral data
is involved (inputtype == 'spd'; dataw = None)
| Other options: see luxpy._CMF['types']
Returns:
:returns:
| ndarray with color appearance correlates (:direction: == 'forward')
| or
| XYZ tristimulus values (:direction: == 'inverse')
Notes:
| This function implements the JOSA A (parameters = 'JOSA')
published model.
| With:
| 1. A correction for the parameter
| in Eq.4 of Fig. 11: 0.952 --> -0.952
|
| 2. The delta_ac and delta_bc white-balance shifts in Eq. 5e & 5f
| should be: -0.028 & 0.821
|
| (cfr. Ccwb = 0.66 in:
| ab_test_out = ab_test_int - Ccwb*ab_gray_adaptation_field_int))
References:
1. `Smet, K. A. G., Webster, M. A., & Whitehead, L. A. (2016).
A simple principled approach for modeling and understanding uniform color metrics.
Journal of the Optical Society of America A, 33(3), A319–A331.
<https://doi.org/10.1364/JOSAA.33.00A319>`_
"""
# get model parameters
args = locals().copy()
if parameters is None:
parameters = _CAM_SWW16_PARAMETERS['JOSA']
if isinstance(parameters, str):
parameters = _CAM_SWW16_PARAMETERS[parameters]
parameters = put_args_in_db(
parameters,
args) #overwrite parameters with other (not-None) args input
#unpack model parameters:
Cc, Ccwb, Cf, Mxyz2lms, cLMS, cab_int, cab_out, calpha, cbeta, cga1, cga2, cgb1, cgb2, cl_int, clambda, lms0 = [
parameters[x] for x in sorted(parameters.keys())
]
# setup default adaptation field:
if (dataw is None):
dataw = _CIE_ILLUMINANTS['C'].copy() # get illuminant C
xyzw = spd_to_xyz(dataw, cieobs=cieobs,
relative=False) # get abs. tristimulus values
if relative == False: #input is expected to be absolute
dataw[1:] = Lw * dataw[
1:] / xyzw[:, 1:2] #dataw = Lw*dataw # make absolute
else:
dataw = dataw # make relative (Y=100)
if inputtype == 'xyz':
dataw = spd_to_xyz(dataw, cieobs=cieobs, relative=relative)
# precomputations:
Mxyz2lms = np.dot(
np.diag(cLMS),
math.normalize_3x3_matrix(Mxyz2lms, np.array([[1, 1, 1]]))
) # normalize matrix for xyz-> lms conversion to ill. E weighted with cLMS
invMxyz2lms = np.linalg.inv(Mxyz2lms)
MAab = np.array([clambda, calpha, cbeta])
invMAab = np.linalg.inv(MAab)
#initialize data and camout:
data = np2d(data).copy(
) # stimulus data (can be upto NxMx3 for xyz, or [N x (M+1) x wl] for spd))
dataw = np2d(dataw).copy(
) # white point (can be upto Nx3 for xyz, or [(N+1) x wl] for spd)
# make axis 1 of dataw have 'same' dimensions as data:
if (data.ndim == 2):
data = np.expand_dims(data, axis=1) # add light source axis 1
if inputtype == 'xyz':
if dataw.shape[
0] == 1: #make dataw have same lights source dimension size as data
dataw = np.repeat(dataw, data.shape[1], axis=0)
else:
if dataw.shape[0] == 2:
dataw = np.vstack(
(dataw[0], np.repeat(dataw[1:], data.shape[1], axis=0)))
# Flip light source dim to axis 0:
data = np.transpose(data, axes=(1, 0, 2))
# Initialize output array:
dshape = list(data.shape)
dshape[-1] = 3 # requested number of correlates: l_int, a_int, b_int
if (inputtype != 'xyz') & (direction == 'forward'):
dshape[-2] = dshape[
-2] - 1 # wavelength row doesn't count & only with forward can the input data be spectral
camout = np.zeros(dshape)
camout.fill(np.nan)
# apply forward/inverse model for each row in data:
for i in range(data.shape[0]):
# stage 1: calculate photon rates of stimulus and adapting field, lmst & lmsf:
if (inputtype != 'xyz'):
if relative == True:
xyzw_abs = spd_to_xyz(np.vstack((dataw[0], dataw[i + 1])),
cieobs=cieobs,
relative=False)
dataw[i +
1] = Lw * dataw[i + 1] / xyzw_abs[0, 1] # make absolute
xyzw = spd_to_xyz(np.vstack((dataw[0], dataw[i + 1])),
cieobs=cieobs,
relative=False)
lmsw = 683.0 * np.dot(Mxyz2lms, xyzw.T).T / _CMF[cieobs]['K']
lmsf = (Yb / 100.0
) * lmsw # calculate adaptation field and convert to l,m,s
if (direction == 'forward'):
if relative == True:
data[i, 1:, :] = Lw * data[i, 1:, :] / xyzw_abs[
0, 1] # make absolute
xyzt = spd_to_xyz(data[i], cieobs=cieobs,
relative=False) / _CMF[cieobs]['K']
lmst = 683.0 * np.dot(Mxyz2lms, xyzt.T).T # convert to l,m,s
else:
lmst = lmsf # put lmsf in lmst for inverse-mode
elif (inputtype == 'xyz'):
if relative == True:
dataw[i] = Lw * dataw[i] / 100.0 # make absolute
lmsw = 683.0 * np.dot(
Mxyz2lms, dataw[i].T).T / _CMF[cieobs]['K'] # convert to lms
lmsf = (Yb / 100.0) * lmsw
if (direction == 'forward'):
if relative == True:
data[i] = Lw * data[i] / 100.0 # make absolute
lmst = 683.0 * np.dot(
Mxyz2lms,
data[i].T).T / _CMF[cieobs]['K'] # convert to lms
else:
lmst = lmsf # put lmsf in lmst for inverse-mode
# stage 2: calculate cone outputs of stimulus lmstp
lmstp = math.erf(Cc * (np.log(lmst / lms0) + Cf * np.log(lmsf / lms0)))
lmsfp = math.erf(Cc * (np.log(lmsf / lms0) + Cf * np.log(lmsf / lms0)))
lmstp = np.vstack(
(lmsfp, lmstp)
) # add adaptation field lms temporarily to lmsp for quick calculation
# stage 3: calculate optic nerve signals, lam*, alphp, betp:
lstar, alph, bet = asplit(np.dot(MAab, lmstp.T).T)
alphp = cga1[0] * alph
alphp[alph < 0] = cga1[1] * alph[alph < 0]
betp = cgb1[0] * bet
betp[bet < 0] = cgb1[1] * bet[bet < 0]
# stage 4: calculate recoded nerve signals, alphapp, betapp:
alphpp = cga2[0] * (alphp + betp)
betpp = cgb2[0] * (alphp - betp)
# stage 5: calculate conscious color perception:
lstar_int = cl_int[0] * (lstar + cl_int[1])
alph_int = cab_int[0] * (np.cos(cab_int[1] * np.pi / 180.0) * alphpp -
np.sin(cab_int[1] * np.pi / 180.0) * betpp)
bet_int = cab_int[0] * (np.sin(cab_int[1] * np.pi / 180.0) * alphpp +
np.cos(cab_int[1] * np.pi / 180.0) * betpp)
lstar_out = lstar_int
if direction == 'forward':
if Ccwb is None:
alph_out = alph_int - cab_out[0]
bet_out = bet_int - cab_out[1]
else:
Ccwb = Ccwb * np.ones((2))
Ccwb[Ccwb < 0.0] = 0.0
Ccwb[Ccwb > 1.0] = 1.0
alph_out = alph_int - Ccwb[0] * alph_int[
0] # white balance shift using adaptation gray background (Yb=20%), with Ccw: degree of adaptation
bet_out = bet_int - Ccwb[1] * bet_int[0]
camout[i] = np.vstack(
(lstar_out[1:], alph_out[1:], bet_out[1:])
).T # stack together and remove adaptation field from vertical stack
elif direction == 'inverse':
labf_int = np.hstack((lstar_int[0], alph_int[0], bet_int[0]))
# get lstar_out, alph_out & bet_out for data:
lstar_out, alph_out, bet_out = asplit(data[i])
# stage 5 inverse:
# undo cortical white-balance:
if Ccwb is None:
alph_int = alph_out + cab_out[0]
bet_int = bet_out + cab_out[1]
else:
Ccwb = Ccwb * np.ones((2))
Ccwb[Ccwb < 0.0] = 0.0
Ccwb[Ccwb > 1.0] = 1.0
alph_int = alph_out + Ccwb[0] * alph_int[
0] # inverse white balance shift using adaptation gray background (Yb=20%), with Ccw: degree of adaptation
bet_int = bet_out + Ccwb[1] * bet_int[0]
lstar_int = lstar_out
alphpp = (1.0 / cab_int[0]) * (
np.cos(-cab_int[1] * np.pi / 180.0) * alph_int -
np.sin(-cab_int[1] * np.pi / 180.0) * bet_int)
betpp = (1.0 / cab_int[0]) * (
np.sin(-cab_int[1] * np.pi / 180.0) * alph_int +
np.cos(-cab_int[1] * np.pi / 180.0) * bet_int)
lstar_int = lstar_out
lstar = (lstar_int / cl_int[0]) - cl_int[1]
# stage 4 inverse:
alphp = 0.5 * (alphpp / cga2[0] + betpp / cgb2[0]
) # <-- alphpp = (Cga2.*(alphp+betp));
betp = 0.5 * (alphpp / cga2[0] - betpp / cgb2[0]
) # <-- betpp = (Cgb2.*(alphp-betp));
# stage 3 invers:
alph = alphp / cga1[0]
bet = betp / cgb1[0]
sa = np.sign(cga1[1])
sb = np.sign(cgb1[1])
alph[(sa * alphp) < 0.0] = alphp[(sa * alphp) < 0] / cga1[1]
bet[(sb * betp) < 0.0] = betp[(sb * betp) < 0] / cgb1[1]
lab = ajoin((lstar, alph, bet))
# stage 2 inverse:
lmstp = np.dot(invMAab, lab.T).T
lmstp[lmstp < -1.0] = -1.0
lmstp[lmstp > 1.0] = 1.0
lmstp = math.erfinv(lmstp) / Cc - Cf * np.log(lmsf / lms0)
lmst = np.exp(lmstp) * lms0
# stage 1 inverse:
xyzt = np.dot(invMxyz2lms, lmst.T).T
if relative == True:
xyzt = (100.0 / Lw) * xyzt
camout[i] = xyzt
# if flipaxis0and1 == True: # loop over shortest dim.
# camout = np.transpose(camout, axes = (1,0,2))
# Flip light source dim back to axis 1:
camout = np.transpose(camout, axes=(1, 0, 2))
if camout.shape[0] == 1:
camout = np.squeeze(camout, axis=0)
return camout
kind='spd')[1:], C[1:, :] * 2, C[1:, :] * 3))
M = _MUNSELL.copy()
rflM = M['R']
rflM = cie_interp(rflM, C[0], kind='rfl')
cieobs = '2006_10'
Lw = 400
Yb = 20
# Normalize to Lw:
xyzw2 = spd_to_xyz(C, cieobs=cieobs, relative=False)
for i in range(C.shape[0] - 1):
C[i + 1] = Lw * C[i + 1] / xyzw2[i, 1]
CM = []
for i in range(C.shape[0] - 1):
CM.append(np.vstack((C[0], C[i + 1] * rflM[1:, :])))
CM = np.transpose(np.array(CM), (1, 0, 2))
xyz, xyzw = spd_to_xyz(C, cieobs=cieobs, relative=True, rfl=rflM, out=2)
xyz = xyz[:4, 0, :]
CM = CM[:5, 0, :]
#xyzw = np.vstack((xyzw[:1,:],xyzw[:1,:]))
xyzw = xyzw[:1, ...]
C = C[:2, :]
print('xyz in:')
lab = cam_sww16(xyz, dataw = xyzw, Yb = Yb, Lw = Lw, Ccwb = 1, relative = True, \
parameters = None, inputtype = 'xyz', direction = 'forward', \
cieobs = cieobs)
print(lab)
print('spd in:')
def spd_to_xyz(data,
relative=True,
rfl=None,
cieobs=_CIEOBS,
K=None,
out=None,
cie_std_dev_obs=None):
"""
Calculates xyz tristimulus values from spectral data.
Args:
:data:
| ndarray or pandas.dataframe with spectral data
| (.shape = (number of spectra + 1, number of wavelengths))
| Note that :data: is never interpolated, only CMFs and RFLs.
| This way interpolation errors due to peaky spectra are avoided.
| Conform CIE15-2018.
:relative:
| True or False, optional
| Calculate relative XYZ (Yw = 100) or absolute XYZ (Y = Luminance)
:rfl:
| ndarray with spectral reflectance functions.
| Will be interpolated if wavelengths do not match those of :data:
:cieobs:
| luxpy._CIEOBS or str, optional
| Determines the color matching functions to be used in the
| calculation of XYZ.
:K:
| None, optional
| e.g. K = 683 lm/W for '1931_2' (relative == False)
| or K = 100/sum(spd*dl) (relative == True)
:out:
| None or 1 or 2, optional
| Determines number and shape of output. (see :returns:)
:cie_std_dev_obs:
| None or str, optional
| - None: don't use CIE Standard Deviate Observer function.
| - 'f1': use F1 function.
Returns:
:returns:
| If rfl is None:
| If out is None: ndarray of xyz values
| (.shape = (data.shape[0],3))
| If out == 1: ndarray of xyz values
| (.shape = (data.shape[0],3))
| If out == 2: (ndarray of xyz, ndarray of xyzw) values
| Note that xyz == xyzw, with (.shape = (data.shape[0],3))
| If rfl is not None:
| If out is None: ndarray of xyz values
| (.shape = (rfl.shape[0],data.shape[0],3))
| If out == 1: ndarray of xyz values
| (.shape = (rfl.shape[0]+1,data.shape[0],3))
| The xyzw values of the light source spd are the first set
| of values of the first dimension. The following values
| along this dimension are the sample (rfl) xyz values.
| If out == 2: (ndarray of xyz, ndarray of xyzw) values
| with xyz.shape = (rfl.shape[0],data.shape[0],3)
| and with xyzw.shape = (data.shape[0],3)
References:
1. `CIE15:2018, “Colorimetry,” CIE, Vienna, Austria, 2018. <https://doi.org/10.25039/TR.015.2018>`_
"""
data = getdata(data,
kind='np') if isinstance(data, pd.DataFrame) else np2d(
data) # convert to np format and ensure 2D-array
# get wl spacing:
dl = getwld(data[0])
# get cmf,k for cieobs:
if isinstance(cieobs, str):
if K is None: K = _CMF[cieobs]['K']
scr = 'dict'
else:
scr = 'cieobs'
if (K is None) & (relative == False): K = 1
# Interpolate to wl of data:
cmf = xyzbar(cieobs=cieobs, scr=scr, wl_new=data[0], kind='np')
# Add CIE standard deviate observer function to cmf if requested:
if cie_std_dev_obs is not None:
cmf_cie_std_dev_obs = xyzbar(cieobs='cie_std_dev_obs_' +
cie_std_dev_obs.lower(),
scr=scr,
wl_new=data[0],
kind='np')
cmf[1:] = cmf[1:] + cmf_cie_std_dev_obs[1:]
# Rescale xyz using k or 100/Yw:
if relative == True: K = 100.0 / np.dot(data[1:], cmf[2, :] * dl)
# Interpolate rfls to lambda range of spd and calculate xyz:
if rfl is not None:
rfl = cie_interp(data=np2d(rfl), wl_new=data[0], kind='rfl')
rfl = np.concatenate((np.ones((1, data.shape[1])),
rfl[1:])) #add rfl = 1 for light source spectrum
xyz = K * np.array(
[np.dot(rfl, (data[1:] * cmf[i + 1, :] * dl).T)
for i in range(3)]) #calculate tristimulus values
rflwasnotnone = 1
else:
rfl = np.ones((1, data.shape[1]))
xyz = (K * (np.dot((cmf[1:] * dl), data[1:].T))[:, None, :])
rflwasnotnone = 0
xyz = np.transpose(xyz, [1, 2, 0]) #order [rfl,spd,xyz]
# Setup output:
if out == 2:
xyzw = xyz[0, ...]
xyz = xyz[rflwasnotnone:, ...]
if rflwasnotnone == 0: xyz = np.squeeze(xyz, axis=0)
return xyz, xyzw
elif out == 1:
if rflwasnotnone == 0: xyz = np.squeeze(xyz, axis=0)
return xyz
else:
xyz = xyz[rflwasnotnone:, ...]
if rflwasnotnone == 0: xyz = np.squeeze(xyz, axis=0)
return xyz
def cam18sl(data,
datab=None,
Lb=[100],
fov=10.0,
inputtype='xyz',
direction='forward',
outin='Q,aS,bS',
parameters=None):
"""
Convert between CIE 2006 10° XYZ tristimulus values (or spectral data)
and CAM18sl color appearance correlates.
Args:
:data:
| ndarray of CIE 2006 10° absolute XYZ tristimulus values or spectral data
| or color appearance attributes of stimulus
:datab:
| ndarray of CIE 2006 10° absolute XYZ tristimulus values or spectral data
| of stimulus background
:Lb:
| [100], optional
| Luminance (cd/m²) value(s) of background(s) calculated using the CIE 2006 10° CMFs
| (only used in case datab == None and the background is assumed to be an Equal-Energy-White)
:fov:
| 10.0, optional
| Field-of-view of stimulus (for size effect on brightness)
:inputtpe:
| 'xyz' or 'spd', optional
| Specifies the type of input:
| tristimulus values or spectral data for the forward mode.
:direction:
| 'forward' or 'inverse', optional
| -'forward': xyz -> cam18sl
| -'inverse': cam18sl -> xyz
:outin:
| 'Q,aS,bS' or str, optional
| 'Q,aS,bS' (brightness and opponent signals for saturation)
| other options: 'Q,aM,bM' (colorfulness)
| (Note that 'Q,aW,bW' would lead to a Cartesian
| a,b-coordinate system centered at (1,0))
| Str specifying the type of
| input (:direction: == 'inverse') and
| output (:direction: == 'forward')
:parameters:
| None or dict, optional
| Set of model parameters.
| - None: defaults to luxpy.cam._CAM18SL_PARAMETERS
| (see references below)
Returns:
:returns:
| ndarray with color appearance correlates (:direction: == 'forward')
| or
| XYZ tristimulus values (:direction: == 'inverse')
Notes:
| * Instead of using the CIE 1964 10° CMFs in some places of the model,
| the CIE 2006 10° CMFs are used througout, making it more self_consistent.
| This has an effect on the k scaling factors (now different those in CAM15u)
| and the illuminant E normalization for use in the chromatic adaptation transform.
| (see future erratum to Hermans et al., 2018)
| * The paper also used an equation for the amount of white W, which is
| based on a Q value not expressed in 'bright' ('cA' = 0.937 instead of 123).
| This has been corrected for in the luxpy version of the model, i.e.
| _CAM18SL_PARAMETERS['cW'][0] has been changed from 2.29 to 1/11672.
| (see future erratum to Hermans et al., 2018)
| * Default output was 'Q,aW,bW' prior to March 2020, but since this
| is an a,b Cartesian system centered on (1,0), the default output
| has been changed to 'Q,aS,bS'.
References:
1. `Hermans, S., Smet, K. A. G., & Hanselaer, P. (2018).
"Color appearance model for self-luminous stimuli."
Journal of the Optical Society of America A, 35(12), 2000–2009.
<https://doi.org/10.1364/JOSAA.35.002000>`_
"""
if parameters is None:
parameters = _CAM18SL_PARAMETERS
outin = outin.split(',')
#unpack model parameters:
cA, cAlms, cHK, cM, cW, ca, calms, cb, cblms, cfov, cieobs, k, naka, unique_hue_data = [
parameters[x] for x in sorted(parameters.keys())
]
# precomputations:
Mlms2xyz = np.linalg.inv(_CMF[cieobs]['M'])
MAab = np.array([cAlms, calms, cblms])
invMAab = np.linalg.inv(MAab)
#-------------------------------------------------
# setup EEW reference field and default background field (Lr should be equal to Lb):
# Get Lb values:
if datab is not None:
if inputtype != 'xyz':
Lb = spd_to_xyz(datab, cieobs=cieobs, relative=False)[..., 1:2]
else:
Lb = datab[..., 1:2]
else:
if isinstance(Lb, list):
Lb = np2dT(Lb)
# Setup EEW ref of same luminance as datab:
if inputtype == 'xyz':
wlr = getwlr(_CAM18SL_WL3)
else:
if datab is None:
wlr = data[0] # use wlr of stimulus data
else:
wlr = datab[0] # use wlr of background data
datar = np.vstack((wlr, np.ones(
(Lb.shape[0], wlr.shape[0])))) # create eew
xyzr = spd_to_xyz(datar, cieobs=cieobs,
relative=False) # get abs. tristimulus values
datar[1:] = datar[1:] / xyzr[..., 1:2] * Lb
# Create datab if None:
if (datab is None):
if inputtype != 'xyz':
datab = datar.copy()
else:
datab = spd_to_xyz(datar, cieobs=cieobs, relative=False)
# prepare data and datab for loop over backgrounds:
# make axis 1 of datab have 'same' dimensions as data:
if (data.ndim == 2):
data = np.expand_dims(data, axis=1) # add light source axis 1
if inputtype == 'xyz':
datar = spd_to_xyz(datar, cieobs=cieobs,
relative=False) # convert to xyz!!
if datab.shape[
0] == 1: #make datab and datar have same lights source dimension (used to store different backgrounds) size as data
datab = np.repeat(datab, data.shape[1], axis=0)
datar = np.repeat(datar, data.shape[1], axis=0)
else:
if datab.shape[0] == 2:
datab = np.vstack(
(datab[0], np.repeat(datab[1:], data.shape[1], axis=0)))
if datar.shape[0] == 2:
datar = np.vstack(
(datar[0], np.repeat(datar[1:], data.shape[1], axis=0)))
# Flip light source/ background dim to axis 0:
data = np.transpose(data, axes=(1, 0, 2))
#-------------------------------------------------
#initialize camout:
dshape = list(data.shape)
dshape[-1] = len(outin) # requested number of correlates
if (inputtype != 'xyz') & (direction == 'forward'):
dshape[-2] = dshape[
-2] - 1 # wavelength row doesn't count & only with forward can the input data be spectral
camout = np.zeros(dshape)
camout.fill(np.nan)
for i in range(data.shape[0]):
# get rho, gamma, beta of background and reference white:
if (inputtype != 'xyz'):
xyzb = spd_to_xyz(np.vstack((datab[0], datab[i + 1:i + 2, :])),
cieobs=cieobs,
relative=False)
xyzr = spd_to_xyz(np.vstack((datar[0], datar[i + 1:i + 2, :])),
cieobs=cieobs,
relative=False)
else:
xyzb = datab[i:i + 1, :]
xyzr = datar[i:i + 1, :]
lmsb = np.dot(_CMF[cieobs]['M'], xyzb.T).T # convert to l,m,s
rgbb = (lmsb / _CMF[cieobs]['K']) * k # convert to rho, gamma, beta
#lmsr = np.dot(_CMF[cieobs]['M'],xyzr.T).T # convert to l,m,s
#rgbr = (lmsr / _CMF[cieobs]['K']) * k # convert to rho, gamma, beta
#rgbr = rgbr/rgbr[...,1:2]*Lb[i] # calculated EEW cone excitations at same luminance values as background
rgbr = np.ones(xyzr.shape) * Lb[
i] # explicitely equal EEW cone excitations at same luminance values as background
if direction == 'forward':
# get rho, gamma, beta of stimulus:
if (inputtype != 'xyz'):
xyz = spd_to_xyz(data[i], cieobs=cieobs, relative=False)
elif (inputtype == 'xyz'):
xyz = data[i]
lms = np.dot(_CMF[cieobs]['M'], xyz.T).T # convert to l,m,s
rgb = (lms / _CMF[cieobs]['K']) * k # convert to rho, gamma, beta
# apply von-kries cat with D = 1:
if (rgbb == 0).any():
Mcat = np.eye(3)
else:
Mcat = np.diag((rgbr / rgbb)[0])
rgba = np.dot(Mcat, rgb.T).T
# apply naka-rushton compression:
rgbc = naka_rushton(rgba,
n=naka['n'],
sig=naka['sig'](rgbr.mean()),
noise=naka['noise'],
scaling=naka['scaling'])
#rgbc = np.ones(rgbc.shape)*rgbc.mean() # test if eew ends up at origin
# calculate achromatic and color difference signals, A, a, b:
Aab = np.dot(MAab, rgbc.T).T
A, a, b = asplit(Aab)
a = ca * a
b = cb * b
# calculate colorfullness like signal M:
M = cM * ((a**2.0 + b**2.0)**0.5)
# calculate brightness Q:
Q = cA * (
A + cHK[0] * M**cHK[1]
) # last term is contribution of Helmholtz-Kohlrausch effect on brightness
# calculate saturation, s:
s = M / Q
S = s # make extra variable, jsut in case 'S' is called
# calculate amount of white, W:
W = 1 / (1.0 + cW[0] * (s**cW[1]))
# adjust Q for size (fov) of stimulus (matter of debate whether to do this before or after calculation of s or W, there was no data on s, M or W for different sized stimuli: after)
Q = Q * (fov / 10.0)**cfov
# calculate hue, h and Hue quadrature, H:
h = hue_angle(a, b, htype='deg')
if 'H' in outin:
H = hue_quadrature(h, unique_hue_data=unique_hue_data)
else:
H = None
# calculate cart. co.:
if 'aM' in outin:
aM = M * np.cos(h * np.pi / 180.0)
bM = M * np.sin(h * np.pi / 180.0)
if 'aS' in outin:
aS = s * np.cos(h * np.pi / 180.0)
bS = s * np.sin(h * np.pi / 180.0)
if 'aW' in outin:
aW = W * np.cos(h * np.pi / 180.0)
bW = W * np.sin(h * np.pi / 180.0)
if (outin != ['Q', 'as', 'bs']):
camout[i] = eval('ajoin((' + ','.join(outin) + '))')
else:
camout[i] = ajoin((Q, aS, bS))
elif direction == 'inverse':
# get Q, M and a, b depending on input type:
if 'aW' in outin:
Q, a, b = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
W = (a**2.0 + b**2.0)**0.5
s = (((1.0 / W) - 1.0) / cW[0])**(1.0 / cW[1])
M = s * Q
if 'aM' in outin:
Q, a, b = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
M = (a**2.0 + b**2.0)**0.5
if 'aS' in outin:
Q, a, b = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
s = (a**2.0 + b**2.0)**0.5
M = s * Q
if 'h' in outin:
Q, WsM, h = asplit(data[i])
Q = Q / (
(fov / 10.0)**cfov
) #adjust Q for size (fov) of stimulus back to that 10° ref
if 'W' in outin:
s = (((1.0 / WsM) - 1.0) / cW[0])**(1.0 / cW[1])
M = s * Q
elif 's' in outin:
M = WsM * Q
elif 'M' in outin:
M = WsM
# calculate achromatic signal, A from Q and M:
A = Q / cA - cHK[0] * M**cHK[1]
# calculate hue angle:
h = hue_angle(a, b, htype='rad')
# calculate a,b from M and h:
a = (M / cM) * np.cos(h)
b = (M / cM) * np.sin(h)
a = a / ca
b = b / cb
# create Aab:
Aab = ajoin((A, a, b))
# calculate rgbc:
rgbc = np.dot(invMAab, Aab.T).T
# decompress rgbc to (adapted) rgba :
rgba = naka_rushton(rgbc,
n=naka['n'],
sig=naka['sig'](rgbr.mean()),
noise=naka['noise'],
scaling=naka['scaling'],
direction='inverse')
# apply inverse von-kries cat with D = 1:
rgb = np.dot(np.diag((rgbb / rgbr)[0]), rgba.T).T
# convert rgb to lms to xyz:
lms = rgb / k * _CMF[cieobs]['K']
xyz = np.dot(Mlms2xyz, lms.T).T
camout[i] = xyz
camout = np.transpose(camout, axes=(1, 0, 2))
if camout.shape[1] == 1:
camout = np.squeeze(camout, axis=1)
return camout
def spd_to_ies_tm30_metrics(St, cri_type = None, \
hbins = 16, start_hue = 0.0,\
scalef = 100, \
vf_model_type = _VF_MODEL_TYPE, \
vf_pcolorshift = _VF_PCOLORSHIFT,\
scale_vf_chroma_to_sample_chroma = False):
"""
Calculates IES TM30 metrics from spectral data.
Args:
:St:
| numpy.ndarray with spectral data
:cri_type:
| None, optional
| If None: defaults to cri_type = 'iesrf'.
| Not none values of :hbins:, :start_hue: and :scalef: overwrite
| input in cri_type['rg_pars']
:hbins:
| None or numpy.ndarray with sorted hue bin centers (°), optional
:start_hue:
| None, optional
:scalef:
| None, optional
| Scale factor for reference circle.
:vf_pcolorshift:
| _VF_PCOLORSHIFT or user defined dict, optional
| The polynomial models of degree 5 and 6 can be fully specified or
| summarized by the model parameters themselved OR by calculating the
| dCoverC and dH at resp. 5 and 6 hues. :VF_pcolorshift: specifies
| these hues and chroma level.
:scale_vf_chroma_to_sample_chroma:
| False, optional
| Scale chroma of reference and test vf fields such that average of
| binned reference chroma equals that of the binned sample chroma
| before calculating hue bin metrics.
Returns:
:data:
| Dictionary with color rendering data:
|
| - 'St, Sr' : ndarray of test SPDs and corresponding ref. illuminants.
| - 'xyz_cct': xyz of white point calculate with cieobs defined for cct calculations in cri_type['cieobs']
| - 'cct, duv': CCT and Duv obtained with cieobs in cri_type['cieobs']['cct']
| - 'xyzti, xyzri': ndarray tristimulus values of test and ref. samples (obtained with with cieobs in cri_type['cieobs']['xyz'])
| - 'xyztw, xyzrw': ndarray tristimulus values of test and ref. white points (obtained with with cieobs in cri_type['cieobs']['xyz'])
| - 'DEi, DEa': ndarray with individual sample color differences DEi and average DEa between test and ref.
| - 'Rf' : ndarray with general color fidelity index values
| - 'Rg' : ndarray with color gamut area index values
| - 'Rfi' : ndarray with specific (sample) color fidelity indices
| - 'Rfhj' : ndarray with local (hue binned) fidelity indices
| - 'DEhj' : ndarray with local (hue binned) color differences
| - 'Rcshj': ndarray with local chroma shifts indices
| - 'Rhshj': ndarray with local hue shifts indices
| - 'hue_bin_data': dict with output from _get_hue_bin_data() [see its help for more info]
| - 'cri_type': same as input (for reference purposes)
| - 'vf' : dictionary with vector field measures and data.
| Keys:
| - 'Rt' : ndarray with general metameric uncertainty index Rt
| - 'Rti' : ndarray with specific metameric uncertainty indices Rti
| - 'Rfhj' : ndarray with local (hue binned) fidelity indices
| obtained from VF model predictions at color space
| pixel coordinates
| - 'DEhj' : ndarray with local (hue binned) color differences
| (same as above)
| - 'Rcshj': ndarray with local chroma shifts indices for vectorfield coordinates
| (same as above)
| - 'Rhshj': ndarray with local hue shifts indicesfor vectorfield coordinates
| (same as above)
| - 'Rfi': ndarray with sample fidelity indices for vectorfield coordinates
| (same as above)
| - 'DEi': ndarray with sample color differences for vectorfield coordinates
| (same as above)
| - 'hue_bin_data': dict with output from _get_hue_bin_data() for vectorfield coordinates
| - 'dataVF': dictionary with output of cri.VFPX.VF_colorshift_model()
"""
if cri_type is None:
cri_type = 'iesrf'
if isinstance(cri_type,str): # get dict
cri_type = copy.deepcopy(_CRI_DEFAULTS[cri_type])
if hbins is not None:
cri_type['rg_pars']['nhbins'] = hbins
if start_hue is not None:
cri_type['rg_pars']['start_hue'] = start_hue
if scalef is not None:
cri_type['rg_pars']['normalized_chroma_ref'] = scalef
#Calculate color rendering measures for SPDs in St:
data,_ = spd_to_cri(St, cri_type = cri_type, out = 'data,hue_bin_data',
fit_gamut_ellipse = True)
hdata = data['hue_bin_data']
Rfhj, Rcshj, Rhshj = data['Rfhj'], data['Rcshj'], data['Rhshj']
cct = data['cct']
#Calculate Metameric uncertainty and base color shifts:
dataVF = VF_colorshift_model(St, cri_type = cri_type,
model_type = vf_model_type,
cspace = cri_type['cspace'],
sampleset = eval(cri_type['sampleset']),
pool = False,
pcolorshift = vf_pcolorshift,
vfcolor = 0)
Rf_ = np.array([dataVF[i]['metrics']['Rf'] for i in range(len(dataVF))]).T
Rt = np.array([dataVF[i]['metrics']['Rt'] for i in range(len(dataVF))]).T
Rti = np.array([dataVF[i]['metrics']['Rti'] for i in range(len(dataVF))][0])
_data_vf = {'Rt' : Rt, 'Rti' : Rti, 'Rf_' : Rf_} # add to dict for output
# Get normalized and sliced hue-bin _hj data for plotting:
rg_pars = cri_type['rg_pars']
nhbins, normalize_gamut, normalized_chroma_ref, start_hue = [rg_pars[x] for x in sorted(rg_pars.keys())]
# Get chroma of samples:
if scale_vf_chroma_to_sample_chroma == True:
jabt_hj_closed, jabr_hj_closed = hdata['jabt_hj_closed'], hdata['jabr_hj_closed']
Cr_hj_s = (np.sqrt(jabr_hj_closed[:-1,...,1]**2 + jabr_hj_closed[:-1,...,2]**2)).mean(axis=0) # for rescaling vector field average reference chroma
#jabtn_hj_closed, jabrn_hj_closed = hdata['jabtn_hj_closed'], hdata['jabrn_hj_closed']
# get vector field data for each source (must be on 2nd dim)
jabt_vf = np.transpose(np.array([np.hstack((np.ones(dataVF[i]['fielddata']['vectorfield']['axt'].shape),dataVF[i]['fielddata']['vectorfield']['axt'],dataVF[i]['fielddata']['vectorfield']['bxt'])) for i in range(cct.shape[0])]),(1,0,2))
jabr_vf = np.transpose(np.array([np.hstack((np.ones(dataVF[i]['fielddata']['vectorfield']['axr'].shape),dataVF[i]['fielddata']['vectorfield']['axr'],dataVF[i]['fielddata']['vectorfield']['bxr'])) for i in range(cct.shape[0])]),(1,0,2))
# Get hue bin data for vector field data:
hue_bin_data_vf = _get_hue_bin_data(jabt_vf, jabr_vf,
start_hue = start_hue, nhbins = nhbins,
normalized_chroma_ref = normalized_chroma_ref )
# Rescale chroma of vector field such that it is on average equal to that of the binned samples:
if scale_vf_chroma_to_sample_chroma == True:
Cr_vf_hj, Cr_vf, Ct_vf = hue_bin_data_vf['Cr_hj'], hue_bin_data_vf['Cr'], hue_bin_data_vf['Ct']
hr_vf, ht_vf = hue_bin_data_vf['hr'], hue_bin_data_vf['ht']
fC = np.nanmean(Cr_hj_s)/np.nanmean(Cr_vf_hj)
jabr_vf[...,1], jabr_vf[...,2] = fC * Cr_vf*np.cos(hr_vf), fC * Cr_vf*np.sin(hr_vf)
jabt_vf[...,1], jabt_vf[...,2] = fC * Ct_vf*np.cos(ht_vf), fC * Ct_vf*np.sin(ht_vf)
# Get new hue bin data for rescaled vector field data:
hue_bin_data_vf = _get_hue_bin_data(jabt_vf, jabr_vf,
start_hue = start_hue, nhbins = nhbins,
normalized_chroma_ref = normalized_chroma_ref )
# Get scale factor and scaling function for Rfx:
scale_factor = cri_type['scale']['cfactor']
scale_fcn = cri_type['scale']['fcn']
# Calculate Local color fidelity, chroma and hue shifts for vector field data:
(Rcshj_vf, Rhshj_vf,
Rfhj_vf, DEhj_vf) = _hue_bin_data_to_rxhj(hue_bin_data_vf,
cri_type = cri_type,
scale_factor = scale_factor,
scale_fcn = scale_fcn)
# Get sample color fidelity for vector field data:
(Rfi_vf, DEi_vf) = _hue_bin_data_to_rfi(hue_bin_data_vf,
cri_type = cri_type,
scale_factor = scale_factor,
scale_fcn = scale_fcn)
# Store in dict:
_data_vf.update({'Rfi' : Rfi_vf, 'DEi' : DEi_vf,
'Rcshj' : Rcshj_vf, 'Rhshj' : Rhshj_vf,
'Rfhj' : Rfhj_vf, 'DEhj': DEhj_vf,
'dataVF' : dataVF, 'hue_bin_data' : hue_bin_data_vf})
# Add to main dictionary:
data['vf'] = _data_vf
return data
