def get_xyz(self, *args):
theta, phi, r = args
x = r * np.sin(theta) * np.cos(phi)
y = r * np.sin(theta) * np.sin(phi)
z = r * np.cos(theta)
z[np.abs(z) < self._TINY] = 0.0
return x, y, z
def spher2cart(theta, phi, r=1., deg=True):
"""
Convert spherical to cartesian coordinates.
Args:
:theta:
| Float, int or ndarray
| Angle with positive z-axis.
:phi:
| Float, int or ndarray
| Angle around positive z-axis starting from x-axis.
:r:
| 1, optional
| Float, int or ndarray
| radius
Returns:
:x, y, z:
| tuple of floats, ints or ndarrays
| Cartesian coordinates
"""
if deg == True:
theta = np.deg2rad(theta)
phi = np.deg2rad(phi)
x = r * np.sin(theta) * np.cos(phi)
y = r * np.sin(theta) * np.sin(phi)
z = r * np.cos(theta)
return x, y, z
def v_to_cik(v, inverse=False):
"""
Calculate 2x2 '(covariance matrix)^-1' elements cik
Args:
:v:
| (Nx5) np.ndarray
| ellipse parameters [Rmax,Rmin,xc,yc,theta]
:inverse:
| If True: return inverse of cik.
Returns:
:cik:
'Nx2x2' (covariance matrix)^-1
Notes:
| cik is not actually a covariance matrix,
| only for a Gaussian or normal distribution!
"""
v = np.atleast_2d(v)
g11 = (1 / v[:, 0] * np.cos(v[:, 4]))**2 + (1 / v[:, 1] *
np.sin(v[:, 4]))**2
g22 = (1 / v[:, 0] * np.sin(v[:, 4]))**2 + (1 / v[:, 1] *
np.cos(v[:, 4]))**2
g12 = (1 / v[:, 0]**2 - 1 / v[:, 1]**2) * np.sin(v[:, 4]) * np.cos(v[:, 4])
cik = np.zeros((g11.shape[0], 2, 2))
for i in range(g11.shape[0]):
cik[i, :, :] = np.vstack((np.hstack(
(g11[i], g12[i])), np.hstack((g12[i], g22[i]))))
if inverse == True:
cik[i, :, :] = np.linalg.inv(cik[i, :, :])
return cik
def pol2cart(theta, r = None, htype = 'deg'):
"""
Convert Cartesion to polar coordinates.
Args:
:theta:
| float or ndarray with theta-coordinates
:r:
| None or float or ndarray with r-coordinates, optional
| If None, r-coordinates are assumed to be in :theta:.
:htype:
| 'deg' or 'rad, optional
| Intput type of :theta:.
Returns:
:returns:
| (float or ndarray of x, float or ndarray of y) coordinates
"""
if htype == 'deg':
d2r = np.pi/180.0
else:
d2r = 1.0
if r is None:
r = theta[...,1].copy()
theta = theta[...,0].copy()
theta = theta*d2r
return r*np.cos(theta), r*np.sin(theta)
def apply_poly_model_at_hue_x(poly_model, pmodel, dCHoverC_res, \
hx = None, Cxr = 40, sig = _VF_SIG):
"""
Applies base color shift model at (hue,chroma) coordinates
Args:
:poly_model:
| function handle to model
:pmodel:
| ndarray with model parameters.
:dCHoverC_res:
| ndarray with residuals between 'dCoverC,dH' of samples
| and 'dCoverC,dH' predicted by the model.
| Note: dCoverC = (Ct - Cr)/Cr and dH = ht - hr
| (predicted from model, see notes luxpy.cri.get_poly_model())
:hx:
| None or ndarray, optional
| None defaults to np.arange(np.pi/10.0,2*np.pi,2*np.pi/10.0)
:Cxr:
| 40, optional
:sig:
| _VF_SIG or float, optional
| Determines smooth transition between hue-bin-boundaries (no hard
cutoff at hue bin boundary).
Returns:
:returns:
| ndarrays with dCoverC_x, dCoverC_x_sig, dH_x, dH_x_sig
| Note '_sig' denotes the uncertainty:
| e.g. dH_x_sig is the uncertainty of dH at input (hue/chroma).
"""
if hx is None:
dh = 2*np.pi/10.0;
hx = np.arange(dh/2,2*np.pi,dh) #hue angles at which to apply model, i.e. calculate 'average' measures
# A calculate reference coordinates:
axr = Cxr*np.cos(hx)
bxr = Cxr*np.sin(hx)
# B apply model at reference coordinates to obtain test coordinates:
axt,bxt,Cxt,hxt,axr,bxr,Cxr,hxr = apply_poly_model_at_x(poly_model, pmodel,axr,bxr)
# C Calculate dC/C, dH for test and ref at fixed hues:
dCoverC_x = (Cxt-Cxr)/(np.hstack((Cxr+Cxt)).max())
dH_x = (180/np.pi)*(hxt-hxr)
# dCoverC_x = np.round(dCoverC_x,decimals = 2)
# dH_x = np.round(dH_x,decimals = 0)
# D calculate 'average' noise measures using sig-value:
href = dCHoverC_res[:,0:1]
dCoverC_res = dCHoverC_res[:,1:2]
dHoverC_res = dCHoverC_res[:,2:3]
dHsigi = np.exp((np.dstack((np.abs(hx-href),np.abs((hx-href-2*np.pi)),np.abs(hx-href-2*np.pi))).min(axis=2)**2)/(-2)/sig)
dH_x_sig = (180/np.pi)*(np.sqrt((dHsigi*(dHoverC_res**2)).sum(axis=0,keepdims=True)/dHsigi.sum(axis=0,keepdims=True)))
#dH_x_sig_avg = np.sqrt(np.sum(dH_x_sig**2,axis=1)/hx.shape[0])
dCoverC_x_sig = (np.sqrt((dHsigi*(dCoverC_res**2)).sum(axis=0,keepdims=True)/dHsigi.sum(axis=0,keepdims=True)))
#dCoverC_x_sig_avg = np.sqrt(np.sum(dCoverC_x_sig**2,axis=1)/hx.shape[0])
return dCoverC_x, dCoverC_x_sig, dH_x, dH_x_sig
def plotcircle(center = np.array([0.,0.]),\
radii = np.arange(0,60,10), \
angles = np.arange(0,350,10),\
color = 'k',linestyle = '--', out = None):
"""
Plot one or more concentric circles.
Args:
:center:
| np.array([0.,0.]) or ndarray with center coordinates, optional
:radii:
| np.arange(0,60,10) or ndarray with radii of circle(s), optional
:angles:
| np.arange(0,350,10) or ndarray with angles (°), optional
:color:
| 'k', optional
| Color for plotting.
:linestyle:
| '--', optional
| Linestyle of circles.
:out:
| None, optional
| If None: plot circles, return (x,y) otherwise.
"""
xs = np.array([0])
ys = xs.copy()
for ri in radii:
x = ri*np.cos(angles*np.pi/180)
y = ri*np.sin(angles*np.pi/180)
xs = np.hstack((xs,x))
ys = np.hstack((ys,y))
if out != 'x,y':
plt.plot(x,y,color = color, linestyle = linestyle)
if out == 'x,y':
return xs,ys
def dtlz2(x, M):
"""
DTLZ2 multi-objective function
This function represents a hyper-sphere.
Using k = 10, the number of dimensions must be n = (M - 1) + k.
The Pareto optimal solutions are obtained when the last k variables of x
are equal to 0.5.
Args:
:x:
| a n x mu ndarray with mu points and n dimensions
:M:
| a scalar with the number of objectives
Returns:
f:
| a m x mu ndarray with mu points and their m objectives computed at
| the input
"""
k = 10
# Error check: the number of dimensions must be M-1+k
n = (M - 1) + k
#this is the default
if x.shape[0] != n:
raise Exception(
'Using k = 10, it is required that the number of dimensions be n = (M - 1) + k = {:1.0f} in this case.'
.format(n))
xm = x[(n - k):, :].copy() #xm contains the last k variables
g = ((xm - 0.5)**2).sum(axis=0)
# Computes the functions:
f = np.empty((M, x.shape[1]))
f[0, :] = (1 + g) * np.prod(np.cos(np.pi / 2 * x[:(M - 1), :]), axis=0)
for ii in range(1, M - 1):
f[ii, :] = (1 + g) * np.prod(np.cos(np.pi / 2 * x[:(M - ii - 1), :]),
axis=0) * np.sin(
np.pi / 2 * x[M - ii - 1, :])
f[M - 1, :] = (1 + g) * np.sin(np.pi / 2 * x[0, :])
return f
def cik_to_v(cik, xyc=None, inverse=False):
"""
Calculate v-format ellipse descriptor from 2x2 'covariance matrix'^-1 cik
Args:
:cik:
| 'Nx2x2' (covariance matrix)^-1
:inverse:
| If True: input is inverse of cik.
Returns:
:v:
| (Nx5) np.ndarray
| ellipse parameters [Rmax,Rmin,xc,yc,theta]
Notes:
| cik is not actually the inverse covariance matrix,
| only for a Gaussian or normal distribution!
"""
if cik.ndim < 3:
cik = cik[None, ...]
if inverse == True:
for i in range(cik.shape[0]):
cik[i, :, :] = np.linalg.inv(cik[i, :, :])
g11 = cik[:, 0, 0]
g22 = cik[:, 1, 1]
g12 = cik[:, 0, 1]
theta = 0.5 * np.arctan2(2 * g12, (g11 - g22)) + (np.pi / 2) * (g12 < 0)
#theta = theta2 + (np.pi/2)*(g12<0)
#theta2 = theta
cottheta = np.cos(theta) / np.sin(theta) #np.cot(theta)
cottheta[np.isinf(cottheta)] = 0
a = 1 / np.sqrt((g22 + g12 * cottheta))
b = 1 / np.sqrt((g11 - g12 * cottheta))
# ensure largest ellipse axis is first (correct angle):
c = b > a
a[c], b[c], theta[c] = b[c], a[c], theta[c] + np.pi / 2
v = np.vstack((a, b, np.zeros(a.shape), np.zeros(a.shape), theta)).T
# add center coordinates:
if xyc is not None:
v[:, 2:4] = xyc
return v
def cik_to_v(cik, xyc=None, inverse=False):
"""
Calculate v-format ellipse descriptor from 2x2 'covariance matrix'^-1 cik
Args:
:cik:
'2x2xN' (covariance matrix)^-1
Returns:
:v:
| (Nx5) np.ndarray
| ellipse parameters [Rmax,Rmin,xc,yc,theta]
Notes:
| cik is not actually the inverse covariance matrix,
| only for a Gaussian or normal distribution!
"""
if inverse == True:
for i in np.arange(cik.shape[0]):
cik[i, :, :] = np.linalg.inv(cik[i, :, :])
g11 = cik[:, 0, 0]
g22 = cik[:, 1, 1]
g12 = cik[:, 0, 1]
theta2 = 1 / 2 * np.arctan2(2 * g12, (g11 - g22))
theta = theta2 + (np.pi / 2) * (g12 < 0)
theta2 = theta
cottheta = np.cos(theta) / np.sin(theta) #np.cot(theta)
cottheta[np.isinf(cottheta)] = 0
a = 1 / np.sqrt((g22 + g12 * cottheta))
b = 1 / np.sqrt((g11 - g12 * cottheta))
v = np.vstack((a, b, np.zeros(a.shape), np.zeros(a.shape), theta)).T
# add center coordinates:
if xyc is not None:
v[:, 2:4] = xyc
return v
def plot_hue_bins(hbins = 16, start_hue = 0.0, scalef = 100, \
plot_axis_labels = False, bin_labels = '#', plot_edge_lines = True, \
plot_center_lines = False, plot_bin_colors = True, \
axtype = 'polar', ax = None, force_CVG_layout = False):
"""
Makes basis plot for Color Vector Graphic (CVG).
Args:
:hbins:
| 16 or ndarray with sorted hue bin centers (°), optional
:start_hue:
| 0.0, optional
:scalef:
| 100, optional
| Scale factor for graphic.
:plot_axis_labels:
| False, optional
| Turns axis ticks on/off (True/False).
:bin_labels:
| None or list[str] or '#', optional
| Plots labels at the bin center hues.
| - None: don't plot.
| - list[str]: list with str for each bin.
| (len(:bin_labels:) = :nhbins:)
| - '#': plots number.
:plot_edge_lines:
| True or False, optional
| Plot grey bin edge lines with '--'.
:plot_center_lines:
| False or True, optional
| Plot colored lines at 'center' of hue bin.
:plot_bin_colors:
| True, optional
| Colorize hue bins.
:axtype:
| 'polar' or 'cart', optional
| Make polar or Cartesian plot.
:ax:
| None or 'new' or 'same', optional
| - None or 'new' creates new plot
| - 'same': continue plot on same axes.
| - axes handle: plot on specified axes.
:force_CVG_layout:
| False or True, optional
| True: Force plot of basis of CVG on first encounter.
Returns:
:returns:
| gcf(), gca(), list with rgb colors for hue bins (for use in
other plotting fcns)
"""
# Setup hbincenters and hsv_hues:
if isinstance(hbins, float) | isinstance(hbins, int):
nhbins = hbins
dhbins = 360 / (nhbins) # hue bin width
hbincenters = np.arange(start_hue + dhbins / 2, 360, dhbins)
hbincenters = np.sort(hbincenters)
else:
hbincenters = hbins
idx = np.argsort(hbincenters)
if isinstance(bin_labels, list) | isinstance(bin_labels, np.ndarray):
bin_labels = bin_labels[idx]
hbincenters = hbincenters[idx]
nhbins = hbincenters.shape[0]
hbincenters = hbincenters * np.pi / 180
# Setup hbin labels:
if bin_labels is '#':
bin_labels = ['#{:1.0f}'.format(i + 1) for i in range(nhbins)]
# initializing the figure
cmap = None
if (ax == None) or (ax == 'new'):
fig = plt.figure()
newfig = True
else:
newfig = False
rect = [0.1, 0.1, 0.8,
0.8] # setting the axis limits in [left, bottom, width, height]
if axtype == 'polar':
# the polar axis:
if newfig == True:
ax = fig.add_axes(rect, polar=True, frameon=False)
else:
#cartesian axis:
if newfig == True:
ax = fig.add_axes(rect)
if (newfig == True) | (force_CVG_layout == True):
# Calculate hue-bin boundaries:
r = np.vstack(
(np.zeros(hbincenters.shape), scalef * np.ones(hbincenters.shape)))
theta = np.vstack((np.zeros(hbincenters.shape), hbincenters))
#t = hbincenters.copy()
dU = np.roll(hbincenters.copy(), -1)
dL = np.roll(hbincenters.copy(), 1)
dtU = dU - hbincenters
dtL = hbincenters - dL
dtU[dtU < 0] = dtU[dtU < 0] + 2 * np.pi
dtL[dtL < 0] = dtL[dtL < 0] + 2 * np.pi
dL = hbincenters - dtL / 2
dU = hbincenters + dtU / 2
dt = (dU - dL)
dM = dL + dt / 2
# Setup color for plotting hue bins:
hsv_hues = hbincenters - 30 * np.pi / 180
hsv_hues = hsv_hues / hsv_hues.max()
edges = np.vstack(
(np.zeros(hbincenters.shape), dL)) # setup hue bin edges array
if axtype == 'cart':
if plot_center_lines == True:
hx = r * np.cos(theta)
hy = r * np.sin(theta)
if bin_labels is not None:
hxv = np.vstack((np.zeros(hbincenters.shape),
1.3 * scalef * np.cos(hbincenters)))
hyv = np.vstack((np.zeros(hbincenters.shape),
1.3 * scalef * np.sin(hbincenters)))
if plot_edge_lines == True:
hxe = np.vstack(
(np.zeros(hbincenters.shape), 1.2 * scalef * np.cos(dL)))
hye = np.vstack(
(np.zeros(hbincenters.shape), 1.2 * scalef * np.sin(dL)))
# Plot hue-bins:
for i in range(nhbins):
# Create color from hue angle:
c = np.abs(np.array(colorsys.hsv_to_rgb(hsv_hues[i], 0.84, 0.9)))
#c = [abs(c[0]),abs(c[1]),abs(c[2])] # ensure all positive elements
if i == 0:
cmap = [c]
else:
cmap.append(c)
if axtype == 'polar':
if plot_edge_lines == True:
ax.plot(edges[:, i],
r[:, i] * 1.2,
color='grey',
marker='None',
linestyle=':',
linewidth=3,
markersize=2)
if plot_center_lines == True:
if np.mod(i, 2) == 1:
ax.plot(theta[:, i],
r[:, i],
color=c,
marker=None,
linestyle='--',
linewidth=2)
else:
ax.plot(theta[:, i],
r[:, i],
color=c,
marker='o',
linestyle='-',
linewidth=3,
markersize=10)
if plot_bin_colors == True:
bar = ax.bar(dM[i],
r[1, i],
width=dt[i],
color=c,
alpha=0.15)
if bin_labels is not None:
ax.text(hbincenters[i],
1.3 * scalef,
bin_labels[i],
fontsize=12,
horizontalalignment='center',
verticalalignment='center',
color=np.array([1, 1, 1]) * 0.3)
if plot_axis_labels == False:
ax.set_xticklabels([])
ax.set_yticklabels([])
else:
if plot_edge_lines == True:
ax.plot(hxe[:, i],
hye[:, i],
color='grey',
marker='None',
linestyle=':',
linewidth=3,
markersize=2)
if plot_center_lines == True:
if np.mod(i, 2) == 1:
ax.plot(hx[:, i],
hy[:, i],
color=c,
marker=None,
linestyle='--',
linewidth=2)
else:
ax.plot(hx[:, i],
hy[:, i],
color=c,
marker='o',
linestyle='-',
linewidth=3,
markersize=10)
if bin_labels is not None:
ax.text(hxv[1, i],
hyv[1, i],
bin_labels[i],
fontsize=12,
horizontalalignment='center',
verticalalignment='center',
color=np.array([1, 1, 1]) * 0.3)
ax.axis(1.1 * np.array(
[hxv.min(), hxv.max(),
hyv.min(), hyv.max()]))
if plot_axis_labels == False:
ax.set_xticklabels([])
ax.set_yticklabels([])
else:
plt.xlabel("a'")
plt.ylabel("b'")
plt.plot(0, 0, color='k', marker='o', linestyle=None)
return plt.gcf(), plt.gca(), cmap
def Ydlep_to_xyz(Ydlep,
cieobs=_CIEOBS,
xyzw=_COLORTF_DEFAULT_WHITE_POINT,
flip_axes=False,
**kwargs):
"""
Convert Y, dominant (complementary) wavelength and excitation purity to XYZ
tristimulus values.
Args:
:Ydlep:
| ndarray with Y, dominant (complementary) wavelength
and excitation purity
:xyzw:
| None or narray with tristimulus values of a single (!) native white point, optional
| None defaults to xyz of CIE D65 using the :cieobs: observer.
:cieobs:
| luxpy._CIEOBS, optional
| CMF set to use when calculating spectrum locus coordinates.
:flip_axes:
| False, optional
| If True: flip axis 0 and axis 1 in Ydelep to increase speed of loop in function.
| (single xyzw with is not flipped!)
Returns:
:xyz:
| ndarray with tristimulus values
"""
Ydlep3 = np3d(Ydlep).copy().astype(np.float)
# flip axis so that longest dim is on first axis (save time in looping):
if (Ydlep3.shape[0] < Ydlep3.shape[1]) & (flip_axes == True):
axes12flipped = True
Ydlep3 = Ydlep3.transpose((1, 0, 2))
else:
axes12flipped = False
# convert xyzw to Yxyw:
Yxyw = xyz_to_Yxy(xyzw)
Yxywo = Yxyw.copy()
# get spectrum locus Y,x,y and wavelengths:
SL = _CMF[cieobs]['bar']
wlsl = SL[0, None].T
Yxysl = xyz_to_Yxy(SL[1:4].T)[:, None]
# center on xyzw:
Yxysl = Yxysl - Yxyw
Yxyw = Yxyw - Yxyw
#split:
Y, dom, pur = asplit(Ydlep3)
Yw, xw, yw = asplit(Yxyw)
Ywo, xwo, ywo = asplit(Yxywo)
Ysl, xsl, ysl = asplit(Yxysl)
# loop over longest dim:
x = np.empty(Y.shape)
y = np.empty(Y.shape)
for i in range(Ydlep3.shape[1]):
# find closest wl's to dom:
#wlslb,wlib = meshblock(wlsl,np.abs(dom[i,:])) #abs because dom<0--> complemtary wl
wlib, wlslb = np.meshgrid(np.abs(dom[:, i]), wlsl)
dwl = np.abs(wlslb - wlib)
q1 = dwl.argmin(axis=0) # index of closest wl
dwl[q1] = 10000.0
q2 = dwl.argmin(axis=0) # index of second closest wl
# calculate x,y of dom:
x_dom_wl = xsl[q1, 0] + (xsl[q2, 0] - xsl[q1, 0]) * (
np.abs(dom[:, i]) - wlsl[q1, 0]) / (wlsl[q2, 0] - wlsl[q1, 0]
) # calculate x of dom. wl
y_dom_wl = ysl[q1, 0] + (ysl[q2, 0] - ysl[q1, 0]) * (
np.abs(dom[:, i]) - wlsl[q1, 0]) / (wlsl[q2, 0] - wlsl[q1, 0]
) # calculate y of dom. wl
# calculate x,y of test:
d_wl = (x_dom_wl**2.0 +
y_dom_wl**2.0)**0.5 # distance from white point to dom
d = pur[:, i] * d_wl
hdom = math.positive_arctan(x_dom_wl, y_dom_wl, htype='deg')
x[:, i] = d * np.cos(hdom * np.pi / 180.0)
y[:, i] = d * np.sin(hdom * np.pi / 180.0)
# complementary:
pc = np.where(dom[:, i] < 0.0)
hdom[pc] = hdom[pc] - np.sign(dom[:, i][pc] -
180.0) * 180.0 # get positive hue angle
# calculate intersection of line through white point and test point and purple line:
xy = np.vstack((x_dom_wl, y_dom_wl)).T
xyw = np.vstack((xw, yw)).T
xypl1 = np.vstack((xsl[0, None], ysl[0, None])).T
xypl2 = np.vstack((xsl[-1, None], ysl[-1, None])).T
da = (xy - xyw)
db = (xypl2 - xypl1)
dp = (xyw - xypl1)
T = np.array([[0.0, -1.0], [1.0, 0.0]])
dap = np.dot(da, T)
denom = np.sum(dap * db, axis=1, keepdims=True)
num = np.sum(dap * dp, axis=1, keepdims=True)
xy_linecross = (num / denom) * db + xypl1
d_linecross = np.atleast_2d(
(xy_linecross[:, 0]**2.0 + xy_linecross[:, 1]**2.0)**0.5).T[:, 0]
x[:, i][pc] = pur[:, i][pc] * d_linecross[pc] * np.cos(
hdom[pc] * np.pi / 180)
y[:, i][pc] = pur[:, i][pc] * d_linecross[pc] * np.sin(
hdom[pc] * np.pi / 180)
Yxy = np.dstack((Ydlep3[:, :, 0], x + xwo, y + ywo))
if axes12flipped == True:
Yxy = Yxy.transpose((1, 0, 2))
else:
Yxy = Yxy.transpose((0, 1, 2))
return Yxy_to_xyz(Yxy).reshape(Ydlep.shape)
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.nan*np.ones(dshape)
# 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
def DE2000(xyzt, xyzr, dtype = 'xyz', DEtype = 'jab', avg = None, avg_axis = 0, out = 'DEi',
xyzwt = None, xyzwr = None, KLCH = None):
"""
Calculate DE2000 color difference.
Args:
:xyzt:
| ndarray with tristimulus values of test data.
:xyzr:
| ndarray with tristimulus values of reference data.
:dtype:
| 'xyz' or 'lab', optional
| Specifies data type in :xyzt: and :xyzr:.
:xyzwt:
| None or ndarray, optional
| White point tristimulus values of test data
| None defaults to the one set in lx.xyz_to_lab()
:xyzwr:
| None or ndarray, optional
| Whitepoint tristimulus values of reference data
| None defaults to the one set in lx.xyz_to_lab()
:DEtype:
| 'jab' or str, optional
| Options:
| - 'jab' : calculates full color difference over all 3 dimensions.
| - 'ab' : calculates chromaticity difference.
| - 'j' : calculates lightness or brightness difference
| (depending on :outin:).
| - 'j,ab': calculates both 'j' and 'ab' options
and returns them as a tuple.
:KLCH:
| None, optional
| Weigths for L, C, H
| None: default to [1,1,1]
:avg:
| None, optional
| None: don't calculate average DE,
| otherwise use function handle in :avg:.
:avg_axis:
| axis to calculate average over, optional
:out:
| 'DEi' or str, optional
| Requested output.
Note:
For the other input arguments, see specific color space used.
Returns:
:returns:
| ndarray with DEi [, DEa] or other as specified by :out:
References:
1. `Sharma, G., Wu, W., & Dalal, E. N. (2005).
The CIEDE2000 color‐difference formula: Implementation notes,
supplementary test data, and mathematical observations.
Color Research & Application, 30(1), 21–30.
<https://doi.org/10.1002/col.20070>`_
"""
if KLCH is None:
KLCH = [1,1,1]
if dtype == 'xyz':
labt = xyz_to_lab(xyzt, xyzw = xyzwt)
labr = xyz_to_lab(xyzr, xyzw = xyzwr)
else:
labt = xyzt
labr = xyzr
Lt = labt[...,0:1]
at = labt[...,1:2]
bt = labt[...,2:3]
Ct = np.sqrt(at**2 + bt**2)
#ht = cam.hue_angle(at,bt,htype = 'rad')
Lr = labr[...,0:1]
ar = labr[...,1:2]
br = labr[...,2:3]
Cr = np.sqrt(ar**2 + br**2)
#hr = cam.hue_angle(at,bt,htype = 'rad')
# Step 1:
Cavg = (Ct + Cr)/2
G = 0.5*(1 - np.sqrt((Cavg**7.0)/((Cavg**7.0) + (25.0**7))))
apt = (1 + G)*at
apr = (1 + G)*ar
Cpt = np.sqrt(apt**2 + bt**2)
Cpr = np.sqrt(apr**2 + br**2)
Cpprod = Cpt*Cpr
hpt = cam.hue_angle(apt,bt, htype = 'deg')
hpr = cam.hue_angle(apr,br, htype = 'deg')
hpt[(apt==0)*(bt==0)] = 0
hpr[(apr==0)*(br==0)] = 0
# Step 2:
dL = np.abs(Lr - Lt)
dCp = np.abs(Cpr - Cpt)
dhp_ = hpr - hpt
dhp = dhp_.copy()
dhp[np.where(np.abs(dhp_) > 180)] = dhp[np.where(np.abs(dhp_) > 180)] - 360
dhp[np.where(np.abs(dhp_) < -180)] = dhp[np.where(np.abs(dhp_) < -180)] + 360
dhp[np.where(Cpprod == 0)] = 0
#dH = 2*np.sqrt(Cpprod)*np.sin(dhp/2*np.pi/180)
dH = deltaH(dhp, Cpprod, htype = 'deg')
# Step 3:
Lp = (Lr + Lt)/2
Cp = (Cpr + Cpt)/2
hps = hpt + hpr
hp = (hpt + hpr)/2
hp[np.where((np.abs(dhp_) > 180) & (hps < 360))] = hp[np.where((np.abs(dhp_) > 180) & (hps < 360))] + 180
hp[np.where((np.abs(dhp_) > 180) & (hps >= 360))] = hp[np.where((np.abs(dhp_) > 180) & (hps >= 360))] - 180
hp[np.where(Cpprod == 0)] = 0
T = 1 - 0.17*np.cos((hp - 30)*np.pi/180) + 0.24*np.cos(2*hp*np.pi/180) +\
0.32*np.cos((3*hp + 6)*np.pi/180) - 0.20*np.cos((4*hp - 63)*np.pi/180)
dtheta = 30*np.exp(-((hp-275)/25)**2)
RC = 2*np.sqrt((Cp**7)/((Cp**7) + (25**7)))
SL = 1 + ((0.015*(Lp-50)**2)/np.sqrt(20 + (Lp - 50)**2))
SC = 1 + 0.045*Cp
SH = 1 + 0.015*Cp*T
RT = -np.sin(2*dtheta*np.pi/180)*RC
kL, kC, kH = KLCH
DEi = ((dL/(kL*SL))**2 , (dCp/(kC*SC))**2 + (dH/(kH*SH))**2 + RT*(dCp/(kC*SC))*(dH/(kH*SH)))
return _process_DEi(DEi, DEtype = DEtype, avg = avg, avg_axis = avg_axis, out = out)
def spd_to_ies_tm30_metrics(SPD, 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:
:data:
| 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:
| dict with color rendering data:
| - 'SPD' : ndarray test SPDs
| - 'bjabt': ndarray with binned jab data under test SPDs
| - 'bjabr': ndarray with binned jab data under reference SPDs
| - 'cct' : ndarray with CCT of test SPD
| - 'duv' : ndarray with distance to blackbody locus of test SPD
| - 'Rf' : ndarray with general color fidelity indices
| - 'Rg' : ndarray with gamut area indices
| - 'Rfi' : ndarray with specific color fidelity indices
| - 'Rfhi' : ndarray with local (hue binned) fidelity indices
| - 'Rcshi': ndarray with local chroma shifts indices
| - 'Rhshi': ndarray with local hue shifts indices
| - 'Rt' : ndarray with general metameric uncertainty index Rt
| - 'Rti' : ndarray with specific metameric uncertainty indices Rti
| - 'Rfhi_vf' : ndarray with local (hue binned) fidelity indices
| obtained from VF model predictions at color space
| pixel coordinates
| - 'Rcshi_vf': ndarray with local chroma shifts indices
| (same as above)
| - 'Rhshi_vf': ndarray with local hue shifts indices
| (same as above)
"""
if cri_type is None:
cri_type = 'iesrf'
#Calculate color rendering measures for SPDs in data:
out = 'Rf,Rg,cct,duv,Rfi,jabt,jabr,Rfhi,Rcshi,Rhshi,cri_type'
if isinstance(cri_type, str): # get dict
cri_type = _CRI_DEFAULTS[cri_type].copy()
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
Rf, Rg, cct, duv, Rfi, jabt, jabr, Rfhi, Rcshi, Rhshi, cri_type = spd_to_cri(
SPD, cri_type=cri_type, out=out)
rg_pars = cri_type['rg_pars']
#Calculate Metameric uncertainty and base color shifts:
dataVF = VF_colorshift_model(SPD,
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])
# Get normalized and sliced sample 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())
]
normalized_chroma_ref = scalef
# np.sqrt((jabr[...,1]**2 + jabr[...,2]**2)).mean(axis = 0).mean()
if scale_vf_chroma_to_sample_chroma == True:
normalize_gamut = False
bjabt, bjabr = gamut_slicer(
jabt,
jabr,
out='jabt,jabr',
nhbins=nhbins,
start_hue=start_hue,
normalize_gamut=normalize_gamut,
normalized_chroma_ref=normalized_chroma_ref,
close_gamut=True)
Cr_s = (np.sqrt(bjabr[:-1, ..., 1]**2 + bjabr[:-1, ..., 2]**2)).mean(
axis=0) # for rescaling vector field average reference chroma
normalize_gamut = True #(for plotting)
bjabt, bjabr = gamut_slicer(jabt,
jabr,
out='jabt,jabr',
nhbins=nhbins,
start_hue=start_hue,
normalize_gamut=normalize_gamut,
normalized_chroma_ref=normalized_chroma_ref,
close_gamut=True)
Rfhi_vf = np.empty(Rfhi.shape)
Rcshi_vf = np.empty(Rcshi.shape)
Rhshi_vf = np.empty(Rhshi.shape)
for i in range(cct.shape[0]):
# Get normalized and sliced VF data for hue specific metrics:
vfjabt = np.hstack(
(np.ones(dataVF[i]['fielddata']['vectorfield']['axt'].shape),
dataVF[i]['fielddata']['vectorfield']['axt'],
dataVF[i]['fielddata']['vectorfield']['bxt']))
vfjabr = np.hstack(
(np.ones(dataVF[i]['fielddata']['vectorfield']['axr'].shape),
dataVF[i]['fielddata']['vectorfield']['axr'],
dataVF[i]['fielddata']['vectorfield']['bxr']))
nhbins, normalize_gamut, normalized_chroma_ref, start_hue = [
rg_pars[x] for x in sorted(rg_pars.keys())
]
vfbjabt, vfbjabr, vfbDEi = gamut_slicer(
vfjabt,
vfjabr,
out='jabt,jabr,DEi',
nhbins=nhbins,
start_hue=start_hue,
normalize_gamut=normalize_gamut,
normalized_chroma_ref=normalized_chroma_ref,
close_gamut=False)
if scale_vf_chroma_to_sample_chroma == True:
#rescale vfbjabt and vfbjabr to same chroma level as bjabr.
Cr_vfb = np.sqrt(vfbjabr[..., 1]**2 + vfbjabr[..., 2]**2)
Cr_vf = np.sqrt(vfjabr[..., 1]**2 + vfjabr[..., 2]**2)
hr_vf = np.arctan2(vfjabr[..., 2], vfjabr[..., 1])
Ct_vf = np.sqrt(vfjabt[..., 1]**2 + vfjabt[..., 2]**2)
ht_vf = np.arctan2(vfjabt[..., 2], vfjabt[..., 1])
fC = Cr_s.mean() / Cr_vfb.mean()
vfjabr[..., 1] = fC * Cr_vf * np.cos(hr_vf)
vfjabr[..., 2] = fC * Cr_vf * np.sin(hr_vf)
vfjabt[..., 1] = fC * Ct_vf * np.cos(ht_vf)
vfjabt[..., 2] = fC * Ct_vf * np.sin(ht_vf)
vfbjabt, vfbjabr, vfbDEi = gamut_slicer(
vfjabt,
vfjabr,
out='jabt,jabr,DEi',
nhbins=nhbins,
start_hue=start_hue,
normalize_gamut=normalize_gamut,
normalized_chroma_ref=normalized_chroma_ref,
close_gamut=False)
scale_factor = cri_type['scale']['cfactor']
scale_fcn = cri_type['scale']['fcn']
vfRfhi, vfRcshi, vfRhshi = jab_to_rhi(
jabt=vfbjabt,
jabr=vfbjabr,
DEi=vfbDEi,
cri_type=cri_type,
scale_factor=scale_factor,
scale_fcn=scale_fcn,
use_bin_avg_DEi=True
) # [:-1,...] removes last row from jab as this was added to close the gamut.
Rfhi_vf[:, i:i + 1] = vfRfhi
Rhshi_vf[:, i:i + 1] = vfRhshi
Rcshi_vf[:, i:i + 1] = vfRcshi
# Create dict with CRI info:
data = {'SPD' : SPD, 'cct' : cct, 'duv' : duv, 'bjabt' : bjabt, 'bjabr' : bjabr,\
'Rf' : Rf, 'Rg' : Rg, 'Rfi': Rfi, 'Rfhi' : Rfhi, 'Rchhi' : Rcshi, 'Rhshi' : Rhshi, \
'Rt' : Rt, 'Rti' : Rti, 'Rfhi_vf' : Rfhi_vf, 'Rfcshi_vf' : Rcshi_vf, 'Rfhshi_vf' : Rhshi_vf, \
'dataVF' : dataVF,'cri_type' : cri_type}
return data
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 = True, 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:
| 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.
: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, 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:
plt.plot(Yxyc[:,1],Yxyc[:,2],color = center_color, linestyle = 'none', marker = center_marker, markersize = center_markersize)
plt.plot(Yxy[:,1],Yxy[:,2],color = line_color, linestyle = line_style, linewidth = line_width, marker = line_marker, markersize = line_markersize)
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()
Yxys = np.transpose(Yxys,axes=(0,2,1))
if out is not None:
return eval(out)
else:
return None
def rotate(v,
vecA=None,
vecB=None,
rot_axis=None,
rot_angle=None,
deg=True,
norm=False):
"""
Rotate vector around rotation axis over angle.
Args:
:v:
| vec3 vector.
:rot_axis:
| None, optional
| vec3 vector specifying rotation axis.
:rot_angle:
| None, optional
| float or int rotation angle.
:deg:
| True, optional
| If False, rot_angle is in radians.
:vecA:, :vecB:
| None, optional
| vec3 vectors defining a normal direction (cross(vecA, vecB)) around
| which to rotate the vector in :v:. If rot_angle is None: rotation
| angle is defined by the in-plane angle between vecA and vecB.
:norm:
| False, optional
| Normalize rotated vector.
"""
if (vecA is not None) & (vecB is not None):
rot_axis = cross(vecA, vecB) # rotation axis
if rot_angle is None:
costheta = dot(vecA, vecB, norm=True) # rotation angle
costheta[costheta > 1] = 1
costheta[costheta < -1] = -1
rot_angle = np.arccos(costheta)
elif (rot_angle is not None):
if deg == True:
rot_angle = np.deg2rad(rot_angle)
else:
raise Exception('vec3.rotate: insufficient not-None input args.')
# normalize rot_axis
rot_axis = rot_axis / rot_axis.norm()
# Create short-hand variables:
u = rot_axis
cost = np.cos(rot_angle)
sint = np.sin(rot_angle)
# Setup rotation matrix:
R = np.asarray([[np.zeros(u.x.shape) for j in range(3)] for i in range(3)])
R[0, 0] = cost + u.x * u.x * (1 - cost)
R[0, 1] = u.x * u.y * (1 - cost) - u.z * sint
R[0, 2] = u.x * u.z * (1 - cost) + u.y * sint
R[1, 0] = u.x * u.y * (1 - cost) + u.z * sint
R[1, 1] = cost + u.y * u.y * (1 - cost)
R[1, 2] = u.y * u.z * (1 - cost) - u.x * sint
R[2, 0] = u.z * u.x * (1 - cost) - u.y * sint
R[2, 1] = u.z * u.y * (1 - cost) + u.x * sint
R[2, 2] = cost + u.z * u.z * (1 - cost)
# calculate dot product of matrix M with vector v:
v3 = vec3(R[0,0]*v.x + R[0,1]*v.y + R[0,2]*v.z, \
R[1,0]*v.x + R[1,1]*v.y + R[1,2]*v.z, \
R[2,0]*v.x + R[2,1]*v.y + R[2,2]*v.z)
if norm == True:
v3 = v3 / v3.norm()
return v3
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.nan * np.ones(dshape)
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 run(data, xyzw, out = 'J,aM,bM', conditions = None, forward = True):
"""
Run CIECAM02 color appearance model in forward or backward modes.
Args:
:data:
| ndarray with relative sample xyz values (forward mode) or J'a'b' coordinates (inverse mode)
:xyzw:
| ndarray with relative white point tristimulus values
:conditions:
| None, optional
| Dictionary with viewing conditions.
| None results in:
| {'La':100, 'Yb':20, 'D':1, 'surround':'avg'}
| For more info see luxpy.cam.ciecam02()?
:forward:
| True, optional
| If True: run in CAM in forward mode, else: inverse mode.
:out:
| 'J,aM,bM', optional
| String with requested output (e.g. "J,aM,bM,M,h") [Forward mode]
| String with inputs in data.
| Input must have data.shape[-1]==3 and last dim of data must have
| the following structure:
| * data[...,0] = J or Q,
| * data[...,1:] = (aM,bM) or (aC,bC) or (aS,bS)
Returns:
:camout:
| ndarray with Jab coordinates or whatever correlates requested in out.
Note:
* This is a simplified, less flexible, but faster version than the main ciecam02().
References:
1. `N. Moroney, M. D. Fairchild, R. W. G. Hunt, C. Li, M. R. Luo, and T. Newman, (2002),
"The CIECAM02 color appearance model,”
IS&T/SID Tenth Color Imaging Conference. p. 23, 2002.
<http://rit-mcsl.org/fairchild/PDFs/PRO19.pdf>`_
"""
outin = out.split(',') if isinstance(out,str) else out
#--------------------------------------------
# Get/ set conditions parameters:
if conditions is not None:
surround_parameters = {'surrounds': ['avg', 'dim', 'dark'],
'avg' : {'c':0.69, 'Nc':1.0, 'F':1.0,'FLL': 1.0},
'dim' : {'c':0.59, 'Nc':0.9, 'F':0.9,'FLL':1.0} ,
'dark' : {'c':0.525, 'Nc':0.8, 'F':0.8,'FLL':1.0}}
La = conditions['La']
Yb = conditions['Yb']
D = conditions['D']
surround = conditions['surround']
if isinstance(surround, str):
surround = surround_parameters[conditions['surround']]
F, FLL, Nc, c = [surround[x] for x in sorted(surround.keys())]
else:
# set defaults:
La, Yb, D, F, FLL, Nc, c = 100, 20, 1, 1, 1, 1, 0.69
#--------------------------------------------
# Define sensor space and cat matrices:
mhpe = np.array([[0.38971,0.68898,-0.07868],
[-0.22981,1.1834,0.04641],
[0.0,0.0,1.0]]) # Hunt-Pointer-Estevez sensors (cone fundamentals)
mcat = np.array([[0.7328, 0.4296, -0.1624],
[ -0.7036, 1.6975, 0.0061],
[ 0.0030, 0.0136, 0.9834]]) # CAT02 sensor space
#--------------------------------------------
# pre-calculate some matrices:
invmcat = np.linalg.inv(mcat)
mhpe_x_invmcat = np.dot(mhpe,invmcat)
if not forward: mcat_x_invmhpe = np.dot(mcat,np.linalg.inv(mhpe))
#--------------------------------------------
# calculate condition dependent parameters:
Yw = xyzw[...,1:2].T
k = 1.0 / (5.0*La + 1.0)
FL = 0.2*(k**4.0)*(5.0*La) + 0.1*((1.0 - k**4.0)**2.0)*((5.0*La)**(1.0/3.0)) # luminance adaptation factor
n = Yb/Yw
Nbb = 0.725*(1/n)**0.2
Ncb = Nbb
z = 1.48 + FLL*n**0.5
if D is None:
D = F*(1.0-(1.0/3.6)*np.exp((-La-42.0)/92.0))
#===================================================================
# WHITE POINT transformations (common to forward and inverse modes):
#--------------------------------------------
# transform from xyzw to cat sensor space:
rgbw = mcat @ xyzw.T
#--------------------------------------------
# apply von Kries cat:
rgbwc = ((D*Yw/rgbw) + (1 - D))*rgbw # factor 100 from ciecam02 is replaced with Yw[i] in cam16, but see 'note' in Fairchild's "Color Appearance Models" (p291 ni 3ed.)
#--------------------------------------------
# convert from cat02 sensor space to cone sensors (hpe):
rgbwp = (mhpe_x_invmcat @ rgbwc).T
#--------------------------------------------
# apply Naka_rushton repsonse compression to white:
NK = lambda x, forward: naka_rushton(x, scaling = 400, n = 0.42, sig = 27.13**(1/0.42), noise = 0.1, forward = forward)
rgbwpa = NK(FL*rgbwp/100.0, True)
pw = np.where(rgbwp<0)
rgbwpa[pw] = 0.1 - (NK(FL*np.abs(rgbwp[pw])/100.0, True) - 0.1)
#--------------------------------------------
# Calculate achromatic signal of white:
Aw = (2.0*rgbwpa[...,0] + rgbwpa[...,1] + (1.0/20.0)*rgbwpa[...,2] - 0.305)*Nbb
# massage shape of data for broadcasting:
if data.ndim == 2: data = data[:,None]
#===================================================================
# STIMULUS transformations
if forward:
#--------------------------------------------
# transform from xyz to cat sensor space:
rgb = math.dot23(mcat, data.T)
#--------------------------------------------
# apply von Kries cat:
rgbc = ((D*Yw/rgbw)[...,None] + (1 - D))*rgb # factor 100 from ciecam02 is replaced with Yw[i] in cam16, but see 'note' in Fairchild's "Color Appearance Models" (p291 ni 3ed.)
#--------------------------------------------
# convert from cat02 sensor space to cone sensors (hpe):
rgbp = math.dot23(mhpe_x_invmcat,rgbc).T
#--------------------------------------------
# apply Naka_rushton repsonse compression:
rgbpa = NK(FL*rgbp/100.0, forward)
p = np.where(rgbp<0)
rgbpa[p] = 0.1 - (NK(FL*np.abs(rgbp[p])/100.0, forward) - 0.1)
#--------------------------------------------
# Calculate achromatic signal:
A = (2.0*rgbpa[...,0] + rgbpa[...,1] + (1.0/20.0)*rgbpa[...,2] - 0.305)*Nbb
#--------------------------------------------
# calculate initial opponent channels:
a = rgbpa[...,0] - 12.0*rgbpa[...,1]/11.0 + rgbpa[...,2]/11.0
b = (1.0/9.0)*(rgbpa[...,0] + rgbpa[...,1] - 2.0*rgbpa[...,2])
#--------------------------------------------
# calculate hue h and eccentricity factor, et:
h = hue_angle(a,b, htype = 'deg')
et = (1.0/4.0)*(np.cos(h*np.pi/180 + 2.0) + 3.8)
#--------------------------------------------
# calculate Hue quadrature (if requested in 'out'):
if 'H' in outin:
H = hue_quadrature(h, unique_hue_data = 'ciecam02')
else:
H = None
#--------------------------------------------
# calculate lightness, J:
if ('J' in outin) | ('Q' in outin) | ('C' in outin) | ('M' in outin) | ('s' in outin) | ('aS' in outin) | ('aC' in outin) | ('aM' in outin):
J = 100.0* (A / Aw)**(c*z)
#--------------------------------------------
# calculate brightness, Q:
if ('Q' in outin) | ('s' in outin) | ('aS' in outin):
Q = (4.0/c)* ((J/100.0)**0.5) * (Aw + 4.0)*(FL**0.25)
#--------------------------------------------
# calculate chroma, C:
if ('C' in outin) | ('M' in outin) | ('s' in outin) | ('aS' in outin) | ('aC' in outin) | ('aM' in outin):
t = ((50000.0/13.0)*Nc*Ncb*et*((a**2.0 + b**2.0)**0.5)) / (rgbpa[...,0] + rgbpa[...,1] + (21.0/20.0*rgbpa[...,2]))
C = (t**0.9)*((J/100.0)**0.5) * (1.64 - 0.29**n)**0.73
#--------------------------------------------
# calculate colorfulness, M:
if ('M' in outin) | ('s' in outin) | ('aM' in outin) | ('aS' in outin):
M = C*FL**0.25
#--------------------------------------------
# calculate saturation, s:
if ('s' in outin) | ('aS' in outin):
s = 100.0* (M/Q)**0.5
#--------------------------------------------
# calculate cartesian coordinates:
if ('aS' in outin):
aS = s*np.cos(h*np.pi/180.0)
bS = s*np.sin(h*np.pi/180.0)
if ('aC' in outin):
aC = C*np.cos(h*np.pi/180.0)
bC = C*np.sin(h*np.pi/180.0)
if ('aM' in outin):
aM = M*np.cos(h*np.pi/180.0)
bM = M*np.sin(h*np.pi/180.0)
#--------------------------------------------
if outin != ['J','aM','bM']:
camout = eval('ajoin(('+','.join(outin)+'))')
else:
camout = ajoin((J,aM,bM))
if camout.shape[1] == 1:
camout = camout[:,0,:]
return camout
elif forward == False:
#--------------------------------------------
# Get Lightness J from data:
if ('J' in outin):
J = data[...,0].copy()
elif ('Q' in outin):
Q = data[...,0].copy()
J = 100.0*(Q / ((Aw + 4.0)*(FL**0.25)*(4.0/c)))**2.0
else:
raise Exception('No lightness or brightness values in data. Inverse CAM-transform not possible!')
#--------------------------------------------
# calculate hue h:
h = hue_angle(data[...,1],data[...,2], htype = 'deg')
#--------------------------------------------
# calculate Colorfulness M or Chroma C or Saturation s from a,b:
MCs = (data[...,1]**2.0 + data[...,2]**2.0)**0.5
if ('aS' in outin):
Q = (4.0/c)* ((J/100.0)**0.5) * (Aw + 4.0)*(FL**0.25)
M = Q*(MCs/100.0)**2.0
C = M/(FL**0.25)
if ('aM' in outin): # convert M to C:
C = MCs/(FL**0.25)
if ('aC' in outin):
C = MCs
#--------------------------------------------
# calculate t from J, C:
t = (C / ((J/100.0)**(1.0/2.0) * (1.64 - 0.29**n)**0.73))**(1.0/0.9)
#--------------------------------------------
# calculate eccentricity factor, et:
et = (np.cos(h*np.pi/180.0 + 2.0) + 3.8) / 4.0
#--------------------------------------------
# calculate achromatic signal, A:
A = Aw*(J/100.0)**(1.0/(c*z))
#--------------------------------------------
# calculate temporary cart. co. at, bt and p1,p2,p3,p4,p5:
at = np.cos(h*np.pi/180.0)
bt = np.sin(h*np.pi/180.0)
p1 = (50000.0/13.0)*Nc*Ncb*et/t
p2 = A/Nbb + 0.305
p3 = 21.0/20.0
p4 = p1/bt
p5 = p1/at
#--------------------------------------------
#q = np.where(np.abs(bt) < np.abs(at))[0]
q = (np.abs(bt) < np.abs(at))
b = p2*(2.0 + p3) * (460.0/1403.0) / (p4 + (2.0 + p3) * (220.0/1403.0) * (at/bt) - (27.0/1403.0) + p3*(6300.0/1403.0))
a = b * (at/bt)
a[q] = p2[q]*(2.0 + p3) * (460.0/1403.0) / (p5[q] + (2.0 + p3) * (220.0/1403.0) - ((27.0/1403.0) - p3*(6300.0/1403.0)) * (bt[q]/at[q]))
b[q] = a[q] * (bt[q]/at[q])
#--------------------------------------------
# calculate post-adaptation values
rpa = (460.0*p2 + 451.0*a + 288.0*b) / 1403.0
gpa = (460.0*p2 - 891.0*a - 261.0*b) / 1403.0
bpa = (460.0*p2 - 220.0*a - 6300.0*b) / 1403.0
#--------------------------------------------
# join values:
rgbpa = ajoin((rpa,gpa,bpa))
#--------------------------------------------
# decompress signals:
rgbp = (100.0/FL)*NK(rgbpa, forward)
#--------------------------------------------
# convert from to cone sensors (hpe) cat02 sensor space:
rgbc = math.dot23(mcat_x_invmhpe,rgbp.T)
#--------------------------------------------
# apply inverse von Kries cat:
rgb = rgbc / ((D*Yw/rgbw)[...,None] + (1.0 - D))
#--------------------------------------------
# transform from cat sensor space to xyz:
xyz = math.dot23(invmcat,rgb).T
return xyz
def get_poly_model(jabt, jabr, modeltype = _VF_MODEL_TYPE):
"""
Setup base color shift model (delta_a, delta_b),
determine model parameters and accuracy.
| Calculates a base color shift (delta) from the ref. chromaticity ar, br.
Args:
:jabt:
| ndarray with jab color coordinates under the test SPD.
:jabr:
| ndarray with jab color coordinates under the reference SPD.
:modeltype:
| _VF_MODEL_TYPE or 'M6' or 'M5', optional
| Specifies degree 5 or degree 6 polynomial model in ab-coordinates.
(see notes below)
Returns:
:returns:
| (poly_model,
| pmodel,
| dab_model,
| dab_res,
| dCHoverC_res,
| dab_std,
| dCHoverC_std)
|
| :poly_model: function handle to model
| :pmodel: ndarray with model parameters
| :dab_model: ndarray with ab model predictions from ar, br.
| :dab_res: ndarray with residuals between 'da,db' of samples and
| 'da,db' predicted by the model.
| :dCHoverC_res: ndarray with residuals between 'dCoverC,dH'
| of samples and 'dCoverC,dH' predicted by the model.
| Note: dCoverC = (Ct - Cr)/Cr and dH = ht - hr
| (predicted from model, see notes below)
| :dab_std: ndarray with std of :dab_res:
| :dCHoverC_std: ndarray with std of :dCHoverC_res:
Notes:
1. Model types:
| poly5_model = lambda a,b,p: p[0]*a + p[1]*b + p[2]*(a**2) + p[3]*a*b + p[4]*(b**2)
| poly6_model = lambda a,b,p: p[0] + p[1]*a + p[2]*b + p[3]*(a**2) + p[4]*a*b + p[5]*(b**2)
2. Calculation of dCoverC and dH:
| dCoverC = (np.cos(hr)*da + np.sin(hr)*db)/Cr
| dHoverC = (np.cos(hr)*db - np.sin(hr)*da)/Cr
"""
at = jabt[...,1]
bt = jabt[...,2]
ar = jabr[...,1]
br = jabr[...,2]
# A. Calculate da, db:
da = at - ar
db = bt - br
# B.1 Calculate model matrix:
# 5-parameter model:
M5 = np.array([[np.sum(ar*ar), np.sum(ar*br), np.sum(ar*ar**2),np.sum(ar*ar*br),np.sum(ar*br**2)],
[np.sum(br*ar), np.sum(br*br), np.sum(br*ar**2),np.sum(br*ar*br),np.sum(br*br**2)],
[np.sum((ar**2)*ar), np.sum((ar**2)*br), np.sum((ar**2)*ar**2),np.sum((ar**2)*ar*br),np.sum((ar**2)*br**2)],
[np.sum(ar*br*ar), np.sum(ar*br*br), np.sum(ar*br*ar**2),np.sum(ar*br*ar*br),np.sum(ar*br*br**2)],
[np.sum((br**2)*ar), np.sum((br**2)*br), np.sum((br**2)*ar**2),np.sum((br**2)*ar*br),np.sum((br**2)*br**2)]])
#6-parameters model
M6 = np.array([[ar.size,np.sum(1.0*ar), np.sum(1.0*br), np.sum(1.0*ar**2),np.sum(1.0*ar*br),np.sum(1.0*br**2)],
[np.sum(ar*1.0),np.sum(ar*ar), np.sum(ar*br), np.sum(ar*ar**2),np.sum(ar*ar*br),np.sum(ar*br**2)],
[np.sum(br*1.0),np.sum(br*ar), np.sum(br*br), np.sum(br*ar**2),np.sum(br*ar*br),np.sum(br*br**2)],
[np.sum((ar**2)*1.0),np.sum((ar**2)*ar), np.sum((ar**2)*br), np.sum((ar**2)*ar**2),np.sum((ar**2)*ar*br),np.sum((ar**2)*br**2)],
[np.sum(ar*br*1.0),np.sum(ar*br*ar), np.sum(ar*br*br), np.sum(ar*br*ar**2),np.sum(ar*br*ar*br),np.sum(ar*br*br**2)],
[np.sum((br**2)*1.0),np.sum((br**2)*ar), np.sum((br**2)*br), np.sum((br**2)*ar**2),np.sum((br**2)*ar*br),np.sum((br**2)*br**2)]])
# B.2 Define model function:
poly5_model = lambda a,b,p: p[0]*a + p[1]*b + p[2]*(a**2) + p[3]*a*b + p[4]*(b**2)
poly6_model = lambda a,b,p: p[0] + p[1]*a + p[2]*b + p[3]*(a**2) + p[4]*a*b + p[5]*(b**2)
if modeltype == 'M5':
M = M5
poly_model = poly5_model
else:
M = M6
poly_model = poly6_model
M = np.linalg.inv(M)
# C.1 Data a,b analysis output:
if modeltype == 'M5':
da_model_parameters = np.dot(M, np.array([np.sum(da*ar), np.sum(da*br), np.sum(da*ar**2),np.sum(da*ar*br),np.sum(da*br**2)]))
db_model_parameters = np.dot(M, np.array([np.sum(db*ar), np.sum(db*br), np.sum(db*ar**2),np.sum(db*ar*br),np.sum(db*br**2)]))
else:
da_model_parameters = np.dot(M, np.array([np.sum(da*1.0),np.sum(da*ar), np.sum(da*br), np.sum(da*ar**2),np.sum(da*ar*br),np.sum(da*br**2)]))
db_model_parameters = np.dot(M, np.array([np.sum(db*1.0),np.sum(db*ar), np.sum(db*br), np.sum(db*ar**2),np.sum(db*ar*br),np.sum(db*br**2)]))
pmodel = np.vstack((da_model_parameters,db_model_parameters))
# D.1 Calculate model da, db:
da_model = poly_model(ar,br,pmodel[0])
db_model = poly_model(ar,br,pmodel[1])
dab_model = np.hstack((da_model,db_model))
# D.2 Calculate residuals for da & db:
da_res = da - da_model
db_res = db - db_model
dab_res = np.hstack((da_res,db_res))
dab_std = np.vstack((np.std(da_res,axis=0),np.std(db_res,axis=0)))
# E Calculate href, Cref:
href = np.arctan2(br,ar)
Cref = (ar**2 + br**2)**0.5
# F Calculate dC/C, dH/C for data and model and calculate residuals:
dCoverC = (np.cos(href)*da + np.sin(href)*db)/Cref
dHoverC = (np.cos(href)*db - np.sin(href)*da)/Cref
dCoverC_model = (np.cos(href)*da_model + np.sin(href)*db_model)/Cref
dHoverC_model = (np.cos(href)*db_model - np.sin(href)*da_model)/Cref
dCoverC_res = dCoverC - dCoverC_model
dHoverC_res = dHoverC - dHoverC_model
dCHoverC_std = np.vstack((np.std(dCoverC_res,axis = 0),np.std(dHoverC_res,axis = 0)))
dCHoverC_res = np.hstack((href,dCoverC_res,dHoverC_res))
return poly_model, pmodel, dab_model, dab_res, dCHoverC_res, dab_std, dCHoverC_std
def cam18sl(data, datab = None, Lb = [100], 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 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,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._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)
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, k, naka, unique_hue_data = [parameters[x] for x in sorted(parameters.keys())]
# precomputations:
Mlms2xyz = np.linalg.inv(_CMF['2006_10']['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 = '2006_10', 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 = '2006_10', 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 = '2006_10', relative = False)
datar = datab.copy()
# 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':
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.nan*np.ones(dshape)
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 = '2006_10', relative = False)
xyzr = spd_to_xyz(np.vstack((datar[0], datar[i+1:i+2,:])), cieobs = '2006_10', relative = False)
else:
xyzb = datab[i:i+1,:]
xyzr = datar[i:i+1,:]
lmsb = np.dot(_CMF['2006_10']['M'],xyzb.T).T # convert to l,m,s
rgbb = (lmsb / _CMF['2006_10']['K']) * k # convert to rho, gamma, beta
#lmsr = np.dot(_CMF['2006_10']['M'],xyzr.T).T # convert to l,m,s
#rgbr = (lmsr / _CMF['2006_10']['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 = '2006_10', relative = False)
elif (inputtype == 'xyz'):
xyz = data[i]
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
# 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
# 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','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 = (((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['2006_10']['K']
xyz = np.dot(Mlms2xyz,lms.T).T
camout[i] = xyz
if camout.shape[0] == 1:
camout = np.squeeze(camout,axis = 0)
return camout
DE_hj[j, ...] = np.nansum(
(DEi * cndr_hj[..., None]) / wr.T,
axis=0).T # local color difference is average of DEi per hue bin !!
# calculate normalized hue-bin averages for jabt, jabr:
ht_hj = cam.hue_angle(jabt_hj[..., 1], jabt_hj[..., 2], htype='rad')
hr_hj = cam.hue_angle(jabr_hj[..., 1], jabr_hj[..., 2], htype='rad')
Ct_hj = ((jabt_hj[..., 1]**2 + jabt_hj[..., 2]**2))**0.5
Cr_hj = ((jabr_hj[..., 1]**2 + jabr_hj[..., 2]**2))**0.5
Ctn_hj = normalized_chroma_ref * Ct_hj / (
Cr_hj + 1e-308) # calculate normalized chroma for samples under test
Ctn_hj[Cr_hj == 0.0] = np.inf
jabtn_hj = jabt_hj.copy()
jabrn_hj = jabr_hj.copy()
jabtn_hj[..., 1], jabtn_hj[...,
2] = Ctn_hj * np.cos(ht_hj), Ctn_hj * np.sin(ht_hj)
jabrn_hj[..., 1], jabrn_hj[..., 2] = normalized_chroma_ref * np.cos(
hr_hj), normalized_chroma_ref * np.sin(hr_hj)
# calculate normalized versions of jabt, jabr:
jabtn = jabt.copy()
jabrn = jabr.copy()
Ctn = np.zeros((jabt.shape[0], jabt.shape[1]))
Crn = Ctn.copy()
for j in range(nhbins):
Ctn = Ctn + (Ct / Cr_hj[j, ...]) * (hr_idx == j)
Crn = Crn + (Cr / Cr_hj[j, ...]) * (hr_idx == j)
Ctn *= normalized_chroma_ref
Crn *= normalized_chroma_ref
jabtn[..., 1] = (Ctn * np.cos(ht))
jabtn[..., 2] = (Ctn * np.sin(ht))
