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 _process_DEi(DEi, DEtype = 'jab', avg = None, avg_axis = 0, out = 'DEi'):
"""
Process color difference input DEi for output (helper function).
Args:
:DEi:
| tuple(J ndarray, ab ndarray).
: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 :out:).
| - 'j,ab': calculates both 'j' and 'ab' options
and returns them as a tuple.
: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:
"""
if (DEi[0].shape[-1] == 1) & (DEi[0].ndim==3):
DEi = tuple((map(lambda x: np.squeeze(x, axis = x.ndim-1),DEi)))
# Calculate correct type of DE:
if DEtype == 'jab':
DEi = np.sqrt(DEi[0] + DEi[1])
elif DEtype == 'ab':
DEi = np.sqrt(DEi[1])
elif DEtype == 'j':
DEi = np.sqrt(DEi[0])
# Calculate average when requested:
if (avg is not None) & ('DEa' in out.split(',')):
if isinstance(DEi, tuple):
DEa = (avg(DEi[0],axis = avg_axis, keepdims = True), avg(DEi[1],axis = avg_axis, keepdims = True))
else:
DEa = avg(DEi,axis = avg_axis, keepdims = True)
if out == 'DEi':
return DEi
elif out == 'DEi,DEa':
return DEi, DEa
else:
return eval(out)
def pitman_morgan(X, Y, verbosity=0):
"""
Pitman-Morgan Test for the difference between correlated variances with paired samples.
Args:
:X,Y:
| ndarrays with data.
:verbosity:
| 0, optional
| If 1: print results.
Returns:
:tval:
| statistic
:pval:
| p-value
:df:
| degree of freedom.
:ratio:
| variance ratio var1/var2 (with var1 > var2).
Note:
1. Based on Gardner, R.C. (2001). Psychological Statistics Using SPSS for Windows. New Jersey, Prentice Hall.
2. Python port from matlab code by Janne Kauttonen (https://nl.mathworks.com/matlabcentral/fileexchange/67910-pitmanmorgantest-x-y; accessed Sep 26, 2019)
"""
N = X.shape[0]
var1, var2 = X.var(axis=0), Y.var(axis=0)
cor = np.corrcoef(X, Y)[0, 1]
# must have var1 > var2:
if var1 < var2:
var1, var2 = var2, var1
ratio = var1 / var2
# formulas from Garder (2001, p.57):
numerator1_S1minusS2 = var1 - var2
numerator2_SQRTnminus2 = np.sqrt(N - 2)
numerator3 = numerator1_S1minusS2 * numerator2_SQRTnminus2
denominator1_4timesS1timesS2 = 4 * var1 * var2
denominator2_rSquared = cor**2
denominator3_1minusrSquared = 1.0 - denominator2_rSquared
denominator4_4timesS1timesS2div1minusrSquared = denominator1_4timesS1timesS2 * denominator3_1minusrSquared
denominator5 = np.sqrt(denominator4_4timesS1timesS2div1minusrSquared)
df = N - 2
if denominator5 == 0:
denominator5 = _EPS
tval = numerator3 / denominator5
# compute stats:
p = 2 * (1.0 - sp.stats.t.cdf(tval, df))
if verbosity == 1:
print('tval = {:1.4f}, df = {:1.1f}, p = {:1.4f}'.format(tval, df, p))
return tval, p, df, ratio
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 fit_ellipse(xy):
"""
Fit an ellipse to supplied data points.
Args:
:xy:
| coordinates of points to fit (Nx2 array)
Returns:
:v:
| vector with ellipse parameters [Rmax,Rmin, xc,yc, theta]
"""
# remove centroid:
center = xy.mean(axis=0)
xy = xy - center
# Fit ellipse:
x, y = xy[:, 0:1], xy[:, 1:2]
D = np.hstack((x * x, x * y, y * y, x, y, np.ones_like(x)))
S, C = np.dot(D.T, D), np.zeros([6, 6])
C[0, 2], C[2, 0], C[1, 1] = 2, 2, -1
U, s, V = np.linalg.svd(np.dot(np.linalg.inv(S), C))
e = U[:, 0]
# get ellipse axis lengths, center and orientation:
b, c, d, f, g, a = e[1] / 2, e[2], e[3] / 2, e[4] / 2, e[5], e[0]
# get ellipse center:
num = b * b - a * c
xc = ((c * d - b * f) / num) + center[0]
yc = ((a * f - b * d) / num) + center[1]
# get ellipse orientation:
theta = np.arctan2(np.array(2 * b), np.array((a - c))) / 2
# axis lengths:
up = 2 * (a * f * f + c * d * d + g * b * b - 2 * b * d * f - a * c * g)
down1 = (b * b - a * c) * ((c - a) * np.sqrt(1 + 4 * b * b / ((a - c) *
(a - c))) -
(c + a))
down2 = (b * b - a * c) * ((a - c) * np.sqrt(1 + 4 * b * b / ((a - c) *
(a - c))) -
(c + a))
a, b = np.sqrt(up / down1), np.sqrt(up / down2)
# assert that a is the major axis (otherwise swap and correct angle)
if (b > a):
b, a = a, b
# ensure the angle is betwen 0 and 2*pi
theta = fmod(theta, 2.0 * np.pi)
return np.hstack((a, b, xc, yc, theta))
def cart2spher(x, y, z, deg=True):
"""
Convert cartesian to spherical coordinates.
Args:
:x, y, z:
| tuple of floats, ints or ndarrays
| Cartesian coordinates
Returns:
: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
"""
r = np.sqrt(x * x + y * y + z * z)
phi = np.arctan2(y, x)
phi[phi < 0.] = phi[phi < 0.] + 2 * np.pi
zdr = z / r
zdr[zdr > 1.] = 1.
zdr[zdr < -1.] = -1
theta = np.arccos(zdr)
if deg == True:
theta = theta * 180 / np.pi
phi = phi * 180 / np.pi
return theta, phi, r
def objfcn(uv_offset, uv0, cct, duv, out = 1):#, cieobs = cieobs, wl = wl, mode = mode):
uv0 = np2d(uv0 + uv_offset)
Yuv0 = np.concatenate((np2d([100.0]), uv0),axis=1)
cct_min, duv_min = xyz_to_cct(Yuv_to_xyz(Yuv0),cieobs = cieobs, out = 'cct,duv',wl = wl, mode = mode, accuracy = accuracy, force_out_of_lut = force_out_of_lut, upper_cct_max = upper_cct_max, approx_cct_temp = approx_cct_temp)
F = np.sqrt(((100.0*(cct_min[0] - cct[0])/(cct[0]))**2.0) + (((duv_min[0] - duv[0])/(duv[0]))**2.0))
if out == 'F':
return F
else:
return np.concatenate((cct_min, duv_min, np2d(F)),axis = 1)
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 apply_poly_model_at_x(poly_model, pmodel,axr,bxr):
"""
Applies base color shift model at cartesian coordinates axr, bxr.
Args:
:poly_model:
| function handle to model
:pmodel:
| ndarray with model parameters.
:axr:
| ndarray with a-coordinates under the reference conditions
:bxr:
| ndarray with b-coordinates under the reference conditions
Returns:
:returns:
| (axt,bxt,Cxt,hxt,
| axr,bxr,Cxr,hxr)
|
| ndarrays with ab-coordinates, chroma and hue
predicted by the model (xt), under the reference (xr).
"""
# Calculate hxr and Cxr:
Cxr = np.sqrt(axr**2 + bxr**2)
hxr = np.arctan(bxr/(axr+_EPS)) #_eps avoid zero-division
# B Set 2nd order color multipliers (shiftd parameters for a and b: pa & pb):
pa = pmodel[0].copy()
pb = pmodel[1].copy()
isM6 = pa.shape[0] == 6
pa[0 + isM6*1] = 1 + pa[0 + isM6*1]
pb[1 + isM6*1] = 1 + pb[1 + isM6*1]
# C Apply model to reference hues using 2nd order multipliers:
axt = poly_model(axr,bxr,pa)
bxt = poly_model(axr,bxr,pb)
Cxt = np.sqrt(axt**2+bxt**2) #test chroma
hxt = np.arctan(bxt/(axt+_EPS))
return axt,bxt,Cxt,hxt,axr,bxr,Cxr,hxr
def magnitude_v(v):
"""
Calculates magnitude of vector.
Args:
:v:
| ndarray with vector
Returns:
:magnitude:
| ndarray
"""
magnitude = np.sqrt(v[:,0]**2 + v[:,1]**2)
return magnitude
def get_tpr(self, *args):
if len(args) > 0:
x, y, z = args
else:
x, y, z = self.x, self.y, self.z
r = np.sqrt(x * x + y * y + z * z)
zdr = np.asarray(z / r)
zdr[zdr > 1.0] = 1.0
zdr[zdr < -1.0] = -1.0
theta = np.arccos(z / r)
phi = np.arctan2(y, x)
phi[phi < 0.0] = phi[phi < 0.0] + 2 * np.pi
phi[r < self._TINY] = 0.0
theta[r < self._TINY] = 0.0
return theta, phi, r
def rms(data,axis = 0, keepdims = False):
"""
Calculate root-mean-square along axis.
Args:
:data:
| list of values or ndarray
:axis:
| 0, optional
| Axis along which to calculate rms.
:keepdims:
| False or True, optional
| Keep original dimensions of array.
Returns:
:returns:
| ndarray with rms values.
"""
data = np2d(data)
return np.sqrt(np.power(data,2).mean(axis=axis, keepdims = keepdims))
def cart2pol(x,y = None, htype = 'deg'):
"""
Convert Cartesion to polar coordinates.
Args:
:x:
| float or ndarray with x-coordinates
:y:
| None or float or ndarray with x-coordinates, optional
| If None, y-coordinates are assumed to be in :x:.
:htype:
| 'deg' or 'rad, optional
| Output type of theta.
Returns:
:returns:
| (float or ndarray of theta, float or ndarray of r) values
"""
if y is None:
y = x[...,1].copy()
x = x[...,0].copy()
return positive_arctan(x,y, htype = htype), np.sqrt(x**2 + y**2)
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 calculate_VF_PX_models(S, cri_type = _VF_CRI_DEFAULT, sampleset = None, pool = False, \
pcolorshift = {'href': np.arange(np.pi/10,2*np.pi,2*np.pi/10),\
'Cref' : _VF_MAXR, 'sig' : _VF_SIG, 'labels' : '#'},\
vfcolor = 'k', verbosity = 0):
"""
Calculate Vector Field and Pixel color shift models.
Args:
: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.
: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:
| :dataVF:, :dataPX:
| Dicts, for more info, see output description of resp.:
luxpy.cri.VF_colorshift_model() and luxpy.cri.PX_colorshift_model()
"""
# calculate VectorField cri_color_shift model:
dataVF = VF_colorshift_model(S, cri_type = cri_type, sampleset = sampleset, vfcolor = vfcolor, pcolorshift = pcolorshift, pool = pool, verbosity = verbosity)
# Set jab_ranges and _deltas for PX-model pixel calculations:
PX_jab_deltas = np.array([_VF_DELTAR,_VF_DELTAR,_VF_DELTAR]) #set same as for vectorfield generation
PX_jab_ranges = np.vstack(([0,100,_VF_DELTAR],[-_VF_MAXR,_VF_MAXR+_VF_DELTAR,_VF_DELTAR], [-_VF_MAXR,_VF_MAXR+_VF_DELTAR,_VF_DELTAR]))#IES4880 gamut
# Calculate shift vectors using vectorfield and pixel methods:
delta_SvsVF_vshift_ab_mean = np.nan*np.ones((len(dataVF),1))
delta_SvsVF_vshift_ab_mean_normalized = delta_SvsVF_vshift_ab_mean.copy()
delta_PXvsVF_vshift_ab_mean = np.nan*np.ones((len(dataVF),1))
delta_PXvsVF_vshift_ab_mean_normalized = delta_PXvsVF_vshift_ab_mean.copy()
dataPX = [[] for k in range(len(dataVF))]
for Snr in range(len(dataVF)):
# Calculate shifts using pixel method, PX:
dataPX[Snr] = PX_colorshift_model(dataVF[Snr]['Jab']['Jabt'][:,0,:],dataVF[Snr]['Jab']['Jabr'][:,0,:], jab_ranges = PX_jab_ranges, jab_deltas = PX_jab_deltas,limit_grid_radius = _VF_MAXR)
# Calculate shift difference between Samples (S) and VectorField model predictions (VF):
delta_SvsVF_vshift_ab = dataVF[Snr]['vshifts']['vshift_ab_s'] - dataVF[Snr]['vshifts']['vshift_ab_s_vf']
delta_SvsVF_vshift_ab_mean[Snr] = np.nanmean(np.sqrt((delta_SvsVF_vshift_ab[...,1:3]**2).sum(axis = delta_SvsVF_vshift_ab[...,1:3].ndim-1)), axis=0)
delta_SvsVF_vshift_ab_mean_normalized[Snr] = delta_SvsVF_vshift_ab_mean[Snr]/dataVF[Snr]['Jab']['DEi'].mean(axis=0)
# Calculate shift difference between PiXel method (PX) and VectorField (VF):
delta_PXvsVF_vshift_ab = dataPX[Snr]['vshifts']['vectorshift_ab_J0'] - dataVF[Snr]['vshifts']['vshift_ab_vf']
delta_PXvsVF_vshift_ab_mean[Snr] = np.nanmean(np.sqrt((delta_PXvsVF_vshift_ab[...,1:3]**2).sum(axis = delta_PXvsVF_vshift_ab[...,1:3].ndim-1)), axis=0)
delta_PXvsVF_vshift_ab_mean_normalized[Snr] = delta_PXvsVF_vshift_ab_mean[Snr]/dataVF[Snr]['Jab']['DEi'].mean(axis=0)
dataVF[Snr]['vshifts']['delta_PXvsVF_vshift_ab_mean'] = delta_PXvsVF_vshift_ab_mean[Snr]
dataVF[Snr]['vshifts']['delta_SvsVF_vshift_ab_mean'] = delta_SvsVF_vshift_ab_mean[Snr]
dataVF[Snr]['vshifts']['delta_SvsVF_vshift_ab_mean_normalized'] = delta_SvsVF_vshift_ab_mean_normalized[Snr]
dataVF[Snr]['vshifts']['delta_PXvsVF_vshift_ab_mean_normalized'] = delta_PXvsVF_vshift_ab_mean_normalized[Snr]
dataPX[Snr]['vshifts']['delta_PXvsVF_vshift_ab_mean'] = dataVF[Snr]['vshifts']['delta_PXvsVF_vshift_ab_mean']
dataPX[Snr]['vshifts']['delta_PXvsVF_vshift_ab_mean_normalized'] = dataVF[Snr]['vshifts']['delta_PXvsVF_vshift_ab_mean_normalized']
return dataVF, dataPX
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 get_pixel_coordinates(jab,
jab_ranges=None,
jab_deltas=None,
limit_grid_radius=0):
"""
Get pixel coordinates corresponding to array of jab color coordinates.
Args:
:jab:
| ndarray of color coordinates
:jab_ranges:
| None or ndarray, optional
| Specifies the pixelization of color space.
| (ndarray.shape = (3,3), with first axis: J,a,b, and second
axis: min, max, delta)
:jab_deltas:
| float or ndarray, optional
| Specifies the sampling range.
| A float uses jab_deltas as the maximum Euclidean distance to select
samples around each pixel center. A ndarray of 3 deltas, uses
a city block sampling around each pixel center.
:limit_grid_radius:
| 0, optional
| A value of zeros keeps grid as specified by axr,bxr.
| A value > 0 only keeps (a,b) coordinates within :limit_grid_radius:
Returns:
:returns:
| gridp, idxp, jabp, samplenrs, samplesIDs
| - :gridp: ndarray with coordinates of all pixel centers.
| - :idxp: list[int] with pixel index for each non-empty pixel
| - :jabp: ndarray with center color coordinates of non-empty pixels
| - :samplenrs: list[list[int]] with sample numbers belong to each
| non-empty pixel
| - :sampleIDs: summarizing list,
| with column order: 'idxp, jabp, samplenrs'
"""
if jab_deltas is None:
jab_deltas = np.array([_VF_DELTAR, _VF_DELTAR, _VF_DELTAR])
if jab_ranges is None:
jab_ranges = np.vstack(
([0, 100, jab_deltas[0]
], [-_VF_MAXR, _VF_MAXR + jab_deltas[1], jab_deltas[1]],
[-_VF_MAXR, _VF_MAXR + jab_deltas[2], jab_deltas[2]]))
# Get pixel grid:
gridp = generate_grid(jab_ranges=jab_ranges,
limit_grid_radius=limit_grid_radius)
# determine pixel coordinates of each sample in jab:
samplesIDs = []
for idx in range(gridp.shape[0]):
# get pixel coordinates:
jp = gridp[idx, 0]
ap = gridp[idx, 1]
bp = gridp[idx, 2]
#Cp = np.sqrt(ap**2+bp**2)
if type(jab_deltas) == np.ndarray:
sampleID = np.where(
((np.abs(jab[..., 0] - jp) <= jab_deltas[0] / 2) &
(np.abs(jab[..., 1] - ap) <= jab_deltas[1] / 2) &
(np.abs(jab[..., 2] - bp) <= jab_deltas[2] / 2)))
else:
sampleID = np.where(
(np.sqrt((jab[..., 0] - jp)**2 + (jab[..., 1] - ap)**2 +
(jab[..., 2] - bp)**2) <= jab_deltas / 2))
if (sampleID[0].shape[0] > 0):
samplesIDs.append(
np.hstack((idx, np.array([jp, ap, bp]), sampleID[0])))
idxp = [np.int(samplesIDs[i][0]) for i in range(len(samplesIDs))]
jabp = np.vstack([samplesIDs[i][1:4] for i in range(len(samplesIDs))])
samplenrs = [
np.array(samplesIDs[i][4:], dtype=int).tolist()
for i in range(len(samplesIDs))
]
return gridp, idxp, jabp, samplenrs, samplesIDs
def xyz_to_rfl(xyz, rfl = None, out = 'rfl_est', \
refspd = None, D = None, cieobs = _CIEOBS, \
cspace = 'ipt', cspace_tf = {},\
k_neighbours = 4, verbosity = 0):
"""
Approximate spectral reflectance of xyz based on k nearest neighbour
interpolation of samples from a standard reflectance set.
Args:
:xyz:
| ndarray with tristimulus values of target points.
:rfl:
| ndarray, optional
| Reflectance set for color coordinate to rfl mapping.
:out:
| 'rfl_est' or str, optional
:refspd:
| None, optional
| Refer ence spectrum for color coordinate to rfl mapping.
| None defaults to D65.
:cieobs:
| _CIEOBS, optional
| CMF set used for calculation of xyz from spectral data.
:cspace:
| 'ipt', optional
| Color space for color coordinate to rfl mapping.
:cspace_tf:
| {}, optional
| Dict with parameters for xyz_to_... and ..._to_xyz transform.
:k_neighbours:
| 4 or int, optional
| Number of nearest neighbours for reflectance spectrum interpolation.
| Neighbours are found using scipy.cKDTree
:verbosity:
| 0, optional
| If > 0: make a plot of the color coordinates of original and
rendered image pixels.
Returns:
:returns:
| :rfl_est:
| ndarrays with estimated reflectance spectra.
"""
# get rfl set:
if rfl is None: # use IESTM30['4880'] set
rfl = _CRI_RFL['ies-tm30']['4880']['5nm']
# get Ref spd:
if refspd is None:
refspd = _CIE_ILLUMINANTS['D65'].copy()
# Calculate lab-type coordinates of standard rfl set under refspd:
xyz_rr, xyz_wr = spd_to_xyz(refspd,
relative=True,
rfl=rfl,
cieobs=cieobs,
out=2)
cspace_tf_copy = cspace_tf.copy()
cspace_tf_copy['xyzw'] = xyz_wr # put correct white point in param. dict
lab_rr = colortf(xyz_rr,
tf=cspace,
fwtf=cspace_tf_copy,
bwtf=cspace_tf_copy)[:, 0, :]
# Convert xyz to lab-type values under refspd:
lab = colortf(xyz, tf=cspace, fwtf=cspace_tf_copy, bwtf=cspace_tf_copy)
# Find rfl (cfr. lab_rr) from rfl set that results in 'near' metameric
# color coordinates for each value in lab_ur (i.e. smallest DE):
# Construct cKDTree:
tree = cKDTree(lab_rr, copy_data=True)
# Interpolate rfls using k nearest neightbours and inverse distance weigthing:
d, inds = tree.query(lab, k=k_neighbours)
if k_neighbours > 1:
w = (1.0 / d**2)[:, :, None] # inverse distance weigthing
rfl_est = np.sum(w * rfl[inds + 1, :], axis=1) / np.sum(w, axis=1)
else:
rfl_est = rfl[inds + 1, :].copy()
rfl_est = np.vstack((rfl[0], rfl_est))
if (verbosity > 0) | ('xyz_est' in out.split(',')) | (
'lab_est' in out.split(',')) | ('DEi_ab' in out.split(',')) | (
'DEa_ab' in out.split(',')):
xyz_est, _ = spd_to_xyz(refspd,
rfl=rfl_est,
relative=True,
cieobs=cieobs,
out=2)
cspace_tf_copy = cspace_tf.copy()
cspace_tf_copy[
'xyzw'] = xyz_wr # put correct white point in param. dict
lab_est = colortf(xyz_est, tf=cspace, fwtf=cspace_tf_copy)[:, 0, :]
DEi_ab = np.sqrt(((lab_est[:, 1:3] - lab[:, 1:3])**2).sum(axis=1))
DEa_ab = DEi_ab.mean()
if verbosity > 0:
ax = plot_color_data(lab[...,1], lab[...,2], z = lab[...,0], \
show = False, cieobs = cieobs, cspace = cspace, \
formatstr = 'ro', label = 'Original')
plot_color_data(lab_est[...,1], lab_est[...,2], z = lab_est[...,0], \
show = True, axh = ax, cieobs = cieobs, cspace = cspace, \
formatstr = 'bd', label = 'Rendered')
if out == 'rfl_est':
return rfl_est
elif out == 'rfl_est,xyz_est':
return rfl_est, xyz_est
else:
return eval(out)
def spd_to_cqs(SPD, version='v9.0', out='Qa', wl=None):
"""
Calculates CQS Qa (Qai) or Qf (Qfi) or Qp (Qpi) for versions v9.0 or v7.5.
Args:
:SPD:
| ndarray with spectral data (can be multiple SPDs,
first axis are the wavelengths)
:version:
| 'v9.0' or 'v7.5', optional
:out:
| 'Qa' or str, optional
| Specifies requested output (e.g. 'Qa,Qai,Qf,cct,duv')
:wl:
| None, optional
| Wavelengths (or [start, end, spacing]) to interpolate the SPDs to.
| None: default to no interpolation
Returns:
:returns:
| float or ndarray with CQS Qa for :out: 'Qa'
| Other output is also possible by changing the :out: str value.
References:
1. `W. Davis and Y. Ohno,
“Color quality scale,” (2010),
Opt. Eng., vol. 49, no. 3, pp. 33602–33616.
<http://spie.org/Publications/Journal/10.1117/1.3360335>`_
"""
outlist = out.split()
if isinstance(version, str):
cri_type = 'cqs-' + version
elif isinstance(version, dict):
cri_type = version
# calculate DEI, labti, labri and get cspace_pars and rg_pars:
DEi, labti, labri, cct, duv, cri_type = spd_to_DEi(
SPD, cri_type=cri_type, out='DEi,jabt,jabr,cct,duv,cri_type', wl=wl)
# further unpack cri_type:
scale_fcn = cri_type['scale']['fcn']
scale_factor = cri_type['scale']['cfactor']
avg = cri_type['avg']
cri_specific_pars = cri_type['cri_specific_pars']
rg_pars = cri_type['rg_pars']
# get maxC: to limit chroma-enhancement:
maxC = cri_specific_pars['maxC']
# make 3d:
test_original_shape = labti.shape
if len(test_original_shape) < 3:
labti = labti[:, None]
labri = labri[:, None]
DEi = DEi[:, None]
cct = cct[:, None]
# calculate Rg for each spd:
Qf = np.zeros((1, labti.shape[1]))
Qfi = np.zeros((labti.shape[0], labti.shape[1]))
if version == 'v7.5':
GA = (9.2672 * (1.0e-11)) * cct**3.0 - (
8.3959 * (1.0e-7)) * cct**2.0 + 0.00255 * cct - 1.612
elif version == 'v9.0':
GA = np.ones(cct.shape)
else:
raise Exception('.cri.spd_to_cqs(): Unrecognized CQS version.')
if ('Qf' in outlist) | ('Qfi' in outlist):
# loop of light source spds
for ii in range(labti.shape[1]):
Qfi[:, ii] = GA[ii] * scale_fcn(DEi[:, ii], [scale_factor[0]])
Qf[:, ii] = GA[ii] * scale_fcn(avg(DEi[:, ii, None], axis=0),
[scale_factor[0]])
if ('Qa' in outlist) | ('Qai' in outlist) | ('Qp' in outlist) | (
'Qpi' in outlist):
Qa = Qf.copy()
Qai = Qfi.copy()
Qp = Qf.copy()
Qpi = Qfi.copy()
# loop of light source spds
for ii in range(labti.shape[1]):
# calculate deltaC:
deltaC = np.sqrt(
np.power(labti[:, ii, 1:3], 2).sum(
axis=1, keepdims=True)) - np.sqrt(
np.power(labri[:, ii, 1:3], 2).sum(axis=1,
keepdims=True))
# limit chroma increase:
DEi_Climited = DEi[:, ii, None].copy()
deltaC_Climited = deltaC.copy()
if maxC is None:
maxC = 10000.0
limitC = np.where(deltaC >= maxC)[0]
deltaC_Climited[limitC] = maxC
p_deltaC_pos = np.where(deltaC > 0.0)[0]
DEi_Climited[p_deltaC_pos] = np.sqrt(
DEi_Climited[p_deltaC_pos]**2.0 - deltaC_Climited[p_deltaC_pos]
**2.0) # increase in chroma is not penalized!
if ('Qa' in outlist) | ('Qai' in outlist):
Qai[:, ii,
None] = GA[ii] * scale_fcn(DEi_Climited, [scale_factor[1]])
Qa[:, ii] = GA[ii] * scale_fcn(avg(DEi_Climited, axis=0),
[scale_factor[1]])
if ('Qp' in outlist) | ('Qpi' in outlist):
deltaC_pos = deltaC_Climited * (deltaC_Climited >= 0.0)
deltaCmu = np.mean(deltaC_Climited * (deltaC_Climited >= 0.0))
Qpi[:, ii, None] = GA[ii] * scale_fcn(
(DEi_Climited - deltaC_pos),
[scale_factor[2]
]) # or ?? np.sqrt(DEi_Climited**2 - deltaC_pos**2) ??
Qp[:, ii] = GA[ii] * scale_fcn(
(avg(DEi_Climited, axis=0) - deltaCmu), [scale_factor[2]])
if ('Qg' in outlist):
Qg = Qf.copy()
for ii in range(labti.shape[1]):
Qg[:, ii] = 100.0 * math.polyarea(
labti[:, ii, 1], labti[:, ii, 2]) / math.polyarea(
labri[:, ii, 1], labri[:, ii, 2]
) # calculate Rg = gamut area ratio of test and ref
if out == 'Qa':
return Qa
else:
return eval(out)
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 __abs__(self):
return np.sqrt(self * self)
def minimizebnd(fun, x0, args=(), method = 'nelder-mead', use_bnd = True, \
bounds = (None,None) , options = None, \
x0_vsize = None, x0_keys = None, **kwargs):
"""
Minimization function that allows for bounds on any type of method in
SciPy's minimize function by transforming the parameters values
| (see Matlab's fminsearchbnd).
| Starting values, and lower and upper bounds can also be provided as a dict.
Args:
:x0:
| parameter starting values
| If x0_keys is None then :x0: is vector else, :x0: is dict and
| x0_size should be provided with length/size of values for each of
the keys in :x0: to convert it to a vector.
:use_bnd:
| True, optional
| False: omits bounds and defaults to regular minimize function.
:bounds:
| (lower, upper), optional
| Tuple of lists or dicts (x0_keys is None) of lower and upper bounds
for each of the parameters values.
:kwargs:
| allows input for other type of arguments (e.g. in OutputFcn)
Note:
For other input arguments, see ?scipy.minimize()
Returns:
:res:
| dict with minimize() output.
| Additionally, function value, fval, of solution is also in :res:,
as well as a vector or dict (if x0 was dict)
with final solutions (res['x'])
"""
# Convert dict to vec:
if isinstance(x0, dict):
x0 = vec_to_dict(dic=x0, vsize=x0_vsize, keys=x0_keys)
if use_bnd == False:
res = minimize(fun, x0, args=args, options=options, **kwargs)
res['fval'] = fun(res['x'], *args)
if x0_keys is None:
res['x_final'] = res['x']
else:
res['x_final'] = vec_to_dict(vec=res['x'],
vsize=x0_vsize,
keys=x0_keys)
return res
else:
LB, UB = bounds
# Convert dict to vec:
if isinstance(LB, dict):
LB = vec_to_dict(dic=LB, vsize=x0_vsize, keys=x0_keys)
if isinstance(LB, dict):
UB = vec_to_dict(dic=UB, vsize=x0_vsize, keys=x0_keys)
#size checks
xsize = x0.shape
x0 = x0.flatten()
n = x0.shape[0]
if LB is None:
LB = -np.inf * np.ones(n)
else:
LB = LB.flatten()
if UB is None:
UB = np.inf * np.ones(n)
else:
UB = UB.flatten()
if (n != LB.shape[0]) | (n != UB.shape[0]):
raise Exception(
'minimizebnd(): x0 is incompatible in size with either LB or UB.'
)
#set default options if necessary
if options is None:
options = {}
# stuff into a struct to pass around
params = {}
params['args'] = args
params['LB'] = LB
params['UB'] = UB
params['fun'] = fun
params['n'] = n
params['OutputFcn'] = None
# % 0 --> unconstrained variable
# % 1 --> lower bound only
# % 2 --> upper bound only
# % 3 --> dual finite bounds
# % 4 --> fixed variable
params['BoundClass'] = np.zeros(n)
for i in np.arange(n):
k = np.isfinite(LB[i]) + 2 * np.isfinite(UB[i])
params['BoundClass'][i] = k
if (k == 3) & (LB[i] == UB[i]):
params['BoundClass'][i] = 4
# transform starting values into their unconstrained
# surrogates. Check for infeasible starting guesses.
x0u = x0
k = 0
for i in np.arange(n):
if params['BoundClass'][i] == 1:
# lower bound only
if x0[i] <= LB[i]:
# infeasible starting value. Use bound.
x0u[k] = 0
else:
x0u[k] = np.sqrt(x0[i] - LB[i])
elif params['BoundClass'][i] == 2:
# upper bound only
if x0[i] >= UB[i]:
# infeasible starting value. use bound.
x0u[k] = 0
else:
x0u[k] = sqrt(UB[i] - x0[i])
elif params['BoundClass'][i] == 2:
# lower and upper bounds
if x0[i] <= LB[i]:
# infeasible starting value
x0u[k] = -np.pi / 2
elif x0[i] >= UB[i]:
# infeasible starting value
x0u[k] = np.pi / 2
else:
x0u[k] = 2 * (x0[i] - LB[i]) / (UB[i] - LB[i]) - 1
# shift by 2*pi to avoid problems at zero in fminsearch
#otherwise, the initial simplex is vanishingly small
x0u[k] = 2 * np.pi + np.asin(
np.hstack((-1, np.hstack((1, x0u[k]).min()))).max())
elif params['BoundClass'][i] == 0:
# unconstrained variable. x0u(i) is set.
x0u[k] = x0[i]
if params['BoundClass'][i] != 4:
# increment k
k += 1
else:
# fixed variable. drop it before fminsearch sees it.
# k is not incremented for this variable.
pass
# if any of the unknowns were fixed, then we need to shorten x0u now.
if k <= n:
x0u = x0u[:k + 1]
# were all the variables fixed?
if x0u.shape[0] == 0:
# All variables were fixed. quit immediately, setting the
# appropriate parameters, then return.
# undo the variable transformations into the original space
x = xtransform(x0u, params)
# final reshape
x = x.reshape(xsize)
# stuff fval with the final value
fval = params['fun'](x, *params['args'])
# minimize was not called
output = {'success': False}
output['x'] = x
output['iterations'] = 0
output['funcount'] = 1
output['algorithm'] = method
output[
'message'] = 'All variables were held fixed by the applied bounds'
output['status'] = 0
# return with no call at all to fminsearch
return output
# Check for an outputfcn. If there is any, then substitute my
# own wrapper function.
# Use a nested function as the OutputFcn wrapper
def outfun_wrapper(x, **kwargs):
# we need to transform x first
xtrans = xtransform(x, params)
# then call the user supplied OutputFcn
stop = params['OutputFcn'](xtrans, **kwargs)
return stop
if 'OutputFcn' in options:
if options['OutputFcn'] is not None:
params['OutputFcn'] = options['OutputFcn']
options['OutputFcn'] = outfun_wrapper
# now we can call minimize, but with our own
# intra-objective function.
res = minimize(intrafun, x0u, args=params, method=method, options=options)
#[xu,fval,exitflag,output] = fminsearch(@intrafun,x0u,options,params);
# get function value:
fval = intrafun(res['x'], params)
# undo the variable transformations into the original space
x = xtransform(res['x'], params)
# final reshape
x = x.reshape(xsize)
res['fval'] = fval
res['x'] = x #overwrite x in res to unconstrained format
if x0_keys is None:
res['x_final'] = res['x']
else:
res['x_final'] = vec_to_dict(vec=res['x'],
vsize=x0_vsize,
keys=x0_keys)
return res
def DE_cspace(xyzt, xyzr, dtype = 'xyz', tf = _CSPACE, DEtype = 'jab', avg = None, avg_axis = 0, out = 'DEi',
xyzwt = None, xyzwr = None, fwtft = {}, fwtfr = {}, KLCH = None,\
camtype = cam._CAM_02_X_DEFAULT_TYPE, ucstype = 'ucs'):
"""
Calculate color difference DE in specific color space.
Args:
:xyzt:
| ndarray with tristimulus values of test data.
:xyzr:
| ndarray with tristimulus values of reference data.
:dtype:
| 'xyz' or 'jab', 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 :fwtft:
or else to the default of cspace.
:xyzwr:
| None or ndarray, optional
| Whitepoint tristimulus values of reference data
| None defaults to the one set in non-empty :fwtfr:
or else to default of cspace.
:tf:
| _CSPACE, optional
| Color space to use for color difference calculation.
:fwtft:
| {}, optional
| Dict with parameters for forward transform
from xyz to cspace for test data.
:fwtfr:
| {}, optional
| Dict with parameters for forward transform
from xyz to cspace for reference data.
:KLCH:
| None, optional
| Weigths for L, C, H
| None: default to [1,1,1]
| KLCH is not used when tf == 'camucs'.
: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.
: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.
:camtype:
| luxpy.cam._CAM_02_X_DEFAULT_TYPE, optional
| Str specifier for CAM type to use, options: 'ciecam02' or 'cam16'.
| Only when DEtype == 'camucs'.
:ucstype:
| 'ucs' or 'lcd' or 'scd', optional
| Str specifier for which type of color attribute compression
| parameters to use:
| -'ucs': uniform color space,
| -'lcd', large color differences,
| -'scd': small color differences
| Only when DEtype == 'camucs'.
Note:
For the other input arguments, see specific color space used.
Returns:
:returns:
| ndarray with DEi [, DEa] or other as specified by :out:
"""
# Get xyzw from dict if xyzw is None & dict is Not None
if xyzwr is not None:
fwtfr['xyzw'] = xyzwr
else:
if bool(fwtfr):
xyzwr = fwtfr['xyzw']
if xyzwt is not None:
fwtft['xyzw'] = xyzwt
else:
if bool(fwtft):
xyzwt = fwtft['xyzw']
if tf == 'camucs':
if dtype == 'xyz':
if fwtfr['xyzw'] is None:
fwtfr['xyzw'] = cam._CAM_DEFAULT_WHITE_POINT
if fwtft['xyzw'] is None:
fwtft['xyzw'] = cam._CAM_DEFAULT_WHITE_POINT
jabt = cam.camucs_structure(xyzt, camtype = camtype, ucstype = ucstype, **fwtft)
jabr = cam.camucs_structure(xyzr, camtype = camtype, ucstype = ucstype, **fwtfr)
else:
jabt = xyzt
jabr = xyzr
KL, c1, c2 = [cam._CAM_02_X_UCS_PARAMETERS[camtype][ucstype][x] for x in sorted(cam._CAM_02_X_UCS_PARAMETERS[camtype][ucstype].keys())]
# Calculate color difference and take account of KL:
DEi = ((((jabt[...,0:1]-jabr[...,0:1])/KL)**2).sum(axis = jabt[...,0:1].ndim - 1, keepdims = True),\
((jabt[...,1:3]-jabr[...,1:3])**2).sum(axis = jabt[...,1:3].ndim - 1, keepdims = True))
elif (tf == 'DE2000') | (tf == 'DE00'):
return DE2000(xyzt, xyzr, dtype = 'xyz', DEtype = DEtype, avg = avg,\
avg_axis = avg_axis, out = out,
xyzwt = xyzwt, xyzwr = xyzwr, KLCH = KLCH)
else:
if dtype == 'xyz':
# Use colortf:
jabt = colortf(xyzt, tf = tf, fwtf = fwtft)
jabr = colortf(xyzr, tf = tf, fwtf = fwtfr)
else:
jabt = xyzt
jabr = xyzr
if (KLCH == None) | (KLCH == [1,1,1]):
# Calculate color difference and take account of KL:
DEi = (((jabt[...,0:1]-jabr[...,0:1])**2).sum(axis = jabt[...,0:1].ndim - 1, keepdims = True),\
((jabt[...,1:3]-jabr[...,1:3])**2).sum(axis = jabt[...,1:3].ndim - 1, keepdims = True))
else: #using LCH specification for use with KLCH weights:
Jt = jabt[...,0:1]
at = jabt[...,1:2]
bt = jabt[...,2:3]
Ct = np.sqrt(at**2 + bt**2)
ht = cam.hue_angle(at,bt,htype = 'rad')
Jr = jabr[...,0:1]
ar = jabr[...,1:2]
br = jabr[...,2:3]
Cr = np.sqrt(ar**2 + br**2)
hr = cam.hue_angle(at,bt,htype = 'rad')
dJ = Jt - Jr
dC = Ct - Cr
dH = ht - hr
DEab2 = ((at-ar)**2 + (bt-br)**2)
dH = np.sqrt(DEab2 - dC**2)
DEi = ((dJ/KLCH[0])**2, (dC/KLCH[1])**2 + (dH/KLCH[2])**2)
return _process_DEi(DEi, DEtype = DEtype, avg = avg, avg_axis = avg_axis, out = out)
def fit_ellipse(xy, center_on_mean_xy=False):
"""
Fit an ellipse to supplied data points.
Args:
:xy:
| coordinates of points to fit (Nx2 array)
:center_on_mean_xy:
| False, optional
| Center ellipse on mean of xy
| (otherwise it might be offset due to solving
| the contrained minization problem: aT*S*a, see ref below.)
Returns:
:v:
| vector with ellipse parameters [Rmax,Rmin, xc,yc, theta]
Reference:
1. Fitzgibbon, A.W., Pilu, M., and Fischer R.B.,
Direct least squares fitting of ellipsees,
Proc. of the 13th Internation Conference on Pattern Recognition,
pp 253–257, Vienna, 1996.
"""
# remove centroid:
# center = xy.mean(axis=0)
# xy = xy - center
# Fit ellipse:
x, y = xy[:, 0:1], xy[:, 1:2]
D = np.hstack((x * x, x * y, y * y, x, y, np.ones_like(x)))
S, C = np.dot(D.T, D), np.zeros([6, 6])
C[0, 2], C[2, 0], C[1, 1] = 2, 2, -1
U, s, V = np.linalg.svd(np.dot(np.linalg.inv(S), C))
e = U[:, 0]
# E, V = np.linalg.eig(np.dot(np.linalg.inv(S), C))
# n = np.argmax(np.abs(E))
# e = V[:,n]
# get ellipse axis lengths, center and orientation:
b, c, d, f, g, a = e[1] / 2, e[2], e[3] / 2, e[4] / 2, e[5], e[0]
# get ellipse center:
num = b * b - a * c
if num == 0:
xc = 0
yc = 0
else:
xc = ((c * d - b * f) / num)
yc = ((a * f - b * d) / num)
# get ellipse orientation:
theta = np.arctan2(np.array(2 * b), np.array((a - c))) / 2
# if b == 0:
# if a > c:
# theta = 0
# else:
# theta = np.pi/2
# else:
# if a > c:
# theta = np.arctan2(2*b,(a-c))/2
# else:
# theta = np.arctan2(2*b,(a-c))/2 + np.pi/2
# axis lengths:
up = 2 * (a * f * f + c * d * d + g * b * b - 2 * b * d * f - a * c * g)
down1 = (b * b - a * c) * ((c - a) * np.sqrt(1 + 4 * b * b / ((a - c) *
(a - c))) -
(c + a))
down2 = (b * b - a * c) * ((a - c) * np.sqrt(1 + 4 * b * b / ((a - c) *
(a - c))) -
(c + a))
a, b = np.sqrt((up / down1)), np.sqrt((up / down2))
# assert that a is the major axis (otherwise swap and correct angle)
if (b > a):
b, a = a, b
# ensure the angle is betwen 0 and 2*pi
theta = fmod(theta, 2.0 * np.pi)
if center_on_mean_xy == True:
xc, yc = xy.mean(axis=0)
return np.hstack((a, b, xc, yc, theta))
def PX_colorshift_model(Jabt,
Jabr,
jab_ranges=None,
jab_deltas=None,
limit_grid_radius=0):
"""
Pixelates the color space and calculates the color shifts in each pixel.
Args:
:Jabt:
| ndarray with color coordinates under the (single) test SPD.
:Jabr:
| ndarray with color coordinates under the (single) reference SPD.
:jab_ranges:
| None or ndarray, optional
| Specifies the pixelization of color space.
| (ndarray.shape = (3,3), with first axis: J,a,b, and second
axis: min, max, delta)
:jab_deltas:
| float or ndarray, optional
| Specifies the sampling range.
| A float uses jab_deltas as the maximum Euclidean distance to select
samples around each pixel center. A ndarray of 3 deltas, uses
a city block sampling around each pixel center.
:limit_grid_radius:
| 0, optional
| A value of zeros keeps grid as specified by axr,bxr.
| A value > 0 only keeps (a,b) coordinates within :limit_grid_radius:
Returns:
:returns:
| dict with the following keys:
| - 'Jab': dict with with ndarrays for:
| Jabt, Jabr, DEi, DEi_ab (only ab-coordinates), DEa (mean)
| and DEa_ab
| - 'vshifts': dict with:
| * 'vectorshift': ndarray with vector shifts between average
| Jabt and Jabr for each pixel
| * 'vectorshift_ab': ndarray with vector shifts averaged
| over J for each pixel
| * 'vectorshift_ab_J0': ndarray with vector shifts averaged
| over J for each pixel of J=0 plane.
| * 'vectorshift_len': length of 'vectorshift'
| * 'vectorshift_ab_len': length of 'vectorshift_ab'
| * 'vectorshift_ab_J0_len': length of 'vectorshift_ab_J0'
| * 'vectorshift_len_DEnormed': length of 'vectorshift'
| normalized to 'DEa'
| * 'vectorshift_ab_len_DEnormed': length of 'vectorshift_ab'
| normalized to 'DEa_ab'
| * 'vectorshift_ab_J0_len_DEnormed': length of 'vectorshift_ab_J0'
| normalized to 'DEa_ab'
| - 'pixeldata': dict with pixel info:
| * 'grid' ndarray with coordinates of all pixel centers.
| * 'idx': list[int] with pixel index for each non-empty pixel
| * 'Jab': ndarray with center coordinates of non-empty pixels
| * 'samplenrs': list[list[int]] with sample numbers belong to
| each non-empty pixel
| * 'IDs: summarizing list,
| with column order: 'idxp, jabp, samplenrs'
| - 'fielddata' : dict with dicts containing data on the calculated
| vector-field and circle-fields
| * 'vectorfield': dict with ndarrays for the ab-coordinates
| under the ref. (axr, bxr) and test (axt, bxt) illuminants,
| centered at the pixel centers corresponding to the
ab-coordinates of the reference illuminant.
"""
# get pixelIDs of all samples under ref. conditions:
gridp, idxp, jabp, pixelsamplenrs, pixelIDs = get_pixel_coordinates(
Jabr,
jab_ranges=jab_ranges,
jab_deltas=jab_deltas,
limit_grid_radius=limit_grid_radius)
# get average Jab coordinates for each pixel:
Npixels = len(idxp) # number of non-empty pixels
Jabr_avg = np.nan * np.ones((gridp.shape[0], 3))
Jabt_avg = Jabr_avg.copy()
for i in range(Npixels):
Jabr_avg[idxp[i], :] = Jabr[pixelsamplenrs[i], :].mean(axis=0)
Jabt_avg[idxp[i], :] = Jabt[pixelsamplenrs[i], :].mean(axis=0)
#jabtemp = Jabr[pixelsamplenrs[i],:]
#jabtempm = Jabr_avg[idxp[i],:]
# calculate Jab vector shift:
vectorshift = Jabt_avg - Jabr_avg
# calculate ab vector shift:
uabs = gridp[gridp[:, 0] == 0, 1:3] #np.unique(gridp[:,1:3],axis=0)
vectorshift_ab_J0 = np.ones((uabs.shape[0], 2)) * np.nan
vectorshift_ab = np.ones((vectorshift.shape[0], 2)) * np.nan
for i in range(uabs.shape[0]):
cond = (gridp[:, 1:3] == uabs[i, :]).all(axis=1)
if cond.any() & np.logical_not(
np.isnan(vectorshift[cond, 1:3]).all()
): #last condition is to avoid warning of taking nanmean of empty slice when all are NaNs
vectorshift_ab_J0[i, :] = np.nanmean(vectorshift[cond, 1:3],
axis=0)
vectorshift_ab[cond, :] = np.nanmean(vectorshift[cond, 1:3],
axis=0)
# Calculate length of shift vectors:
vectorshift_len = np.sqrt((vectorshift**2).sum(axis=vectorshift.ndim - 1))
vectorshift_ab_len = np.sqrt(
(vectorshift_ab**2).sum(axis=vectorshift_ab.ndim - 1))
vectorshift_ab_J0_len = np.sqrt(
(vectorshift_ab_J0**2).sum(axis=vectorshift_ab_J0.ndim - 1))
# Calculate average DE for normalization of vectorshifts
DEi_Jab_avg = np.sqrt(((Jabt - Jabr)**2).sum(axis=Jabr.ndim - 1))
DE_Jab_avg = DEi_Jab_avg.mean(axis=0)
DEi_ab_avg = np.sqrt(
((Jabt[..., 1:3] - Jabr[..., 1:3])**2).sum(axis=Jabr[..., 1:3].ndim -
1))
DE_ab_avg = DEi_ab_avg.mean(axis=0)
# calculate vectorfield:
axr = uabs[:, 0, None]
bxr = uabs[:, 1, None]
axt = axr + vectorshift_ab_J0[:, 0, None]
bxt = bxr + vectorshift_ab_J0[:, 1, None]
data = {
'Jab': {
'Jabr': Jabr_avg,
'Jabt': Jabt_avg,
'DEi': DEi_Jab_avg,
'DEi_ab': DEi_ab_avg,
'DEa': DE_Jab_avg,
'DEa_ab': DE_ab_avg
},
'vshifts': {
'vectorshift': vectorshift,
'vectorshift_ab': vectorshift_ab,
'vectorshift_ab_J0': vectorshift_ab_J0,
'vectorshift_len': vectorshift_len,
'vectorshift_ab_len': vectorshift_ab_len,
'vectorshift_ab_J0_len': vectorshift_ab_J0_len,
'vectorshift_len_DEnormed': vectorshift_len / DE_Jab_avg,
'vectorshift_ab_len_DEnormed': vectorshift_ab_len / DE_ab_avg,
'vectorshift_ab_J0_len_DEnormed': vectorshift_ab_J0_len / DE_ab_avg
},
'pixeldata': {
'grid': gridp,
'idx': idxp,
'Jab': jabp,
'samplenrs': pixelsamplenrs,
'IDs': pixelIDs
},
'fielddata': {
'vectorfield': {
'axr': axr,
'bxr': bxr,
'axt': axt,
'bxt': bxt
}
}
}
return data
def plot_shift_data(data, fieldtype = 'vectorfield', scalef = _VF_MAXR, color = 'k', \
axtype = 'polar', ax = None, \
hbins = 10, start_hue = 0.0, bin_labels = '#', plot_center_lines = True, \
plot_axis_labels = False, plot_edge_lines = False, plot_bin_colors = True, \
force_CVG_layout = True):
"""
Plots vector or circle fields generated by VFcolorshiftmodel()
or PXcolorshiftmodel().
Args:
:data:
| dict generated by VFcolorshiftmodel() or PXcolorshiftmodel()
| Must contain 'fielddata'- key, which is a dict with possible keys:
| - key: 'vectorfield': ndarray with vector field data
| - key: 'circlefield': ndarray with circle field data
:color:
| 'k', optional
| Color for plotting the vector-fields.
: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.
:hbins:
| 16 or ndarray with sorted hue bin centers (°), optional
:start_hue:
| _VF_MAXR, 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.
:force_CVG_layout:
| False or True, optional
| True: Force plot of basis of CVG.
Returns:
:returns:
| figCVG, hax, cmap
| :figCVG: handle to CVG figure
| :hax: handle to CVG axes
| :cmap: list with rgb colors for hue bins
| (for use in other plotting fcns)
"""
# Plot basis of CVG:
figCVG, hax, cmap = plot_hue_bins(hbins = hbins, axtype = axtype, ax = ax, plot_center_lines = plot_center_lines, plot_edge_lines = plot_edge_lines, plot_bin_colors = plot_bin_colors, scalef = scalef, force_CVG_layout = force_CVG_layout, bin_labels = bin_labels)
# plot vector field:
if data is not None:
if fieldtype is not None:
vf = data['fielddata'][fieldtype]
if axtype == 'polar':
if fieldtype == 'vectorfield':
vfrtheta = math.positive_arctan(vf['axr'], vf['bxr'],htype = 'rad')
vfrr = np.sqrt(vf['axr']**2 + vf['bxr']**2)
hax.quiver(vfrtheta, vfrr, vf['axt'] - vf['axr'], vf['bxt'] - vf['bxr'], headlength=3,color = color,angles='uv', scale_units='y', scale = 2,linewidth = 0.5)
else:
vfttheta = math.positive_arctan(vf['axt'], vf['bxt'],htype = 'rad')
vfrtheta = math.positive_arctan(vf['axr'], vf['bxr'],htype = 'rad')
vftr = np.sqrt(vf['axt']**2 + vf['bxt']**2)
dh = (math.angle_v1v2(np.hstack((vf['axt'],vf['bxt'])),np.hstack((vf['axr'],vf['bxr'])),htype='deg')[:,None]) #hue shift
dh = dh/np.nanmax(dh)
plt.set_cmap('jet')
hax.scatter(vfttheta, vftr, s = 100*dh, c = dh, linestyle = 'None', marker = 'o',norm = None)
hax.set_ylim([0, 1.1*scalef])
else:
if fieldtype == 'vectorfield':
hax.quiver(vf['axr'], vf['bxr'], vf['axt'] - vf['axr'], vf['bxt'] - vf['bxr'], headlength=1,color = color,angles='uv', scale_units='xy', scale = 1,linewidth = 0.5)
else:
hax.plot(vf['axr'], vf['bxr'], color = color, marker = '.',linestyle = 'None')
return figCVG, hax, cmap
((_hr - start_hue * np.pi / 180) / 2 / np.pi) *
nhbins) # because of start_hue bin range can be different from 0 : n-1
_hbins[_hbins >= _nhbins] = _hbins[
_hbins >= _nhbins] - _nhbins # reset binnumbers to 0 : n-1 range
_hbins[_hbins < 0] = (
_nhbins - 2) - _hbins[_hbins < 0] # reset binnumbers to 0 : n-1 range
_jabtii = np.zeros((_nhbins, 3))
_jabrii = np.zeros((_nhbins, 3))
for i in range(nhbins):
if i in _hbins:
_jabtii[i, :] = _jab_test[_hbins == i, ii, :].mean(axis=0)
_jabrii[i, :] = _jab_ref[_hbins == i, ii, :].mean(axis=0)
_DEi[i, ii] = np.sqrt(
np.power((_jab_test[_hbins == i, ii, :] -
_jab_ref[_hbins == i, ii, :]),
2).sum(axis=_jab_test[_hbins == i, ii, :].ndim -
1)).mean(axis=0)
_jabt_hj = _jabtii.copy()
_jabr_hj = _jabrii.copy()
if normalize_gamut == True:
#renormalize jab_test, jab_ref using jabrii:
# if ('jabti' in out) | ('jabri' in out):
_Cti = np.sqrt(_jab_test[:, ii, 1]**2 + _jab_test[:, ii, 2]**2)
_Cri = np.sqrt(_jab_ref[:, ii, 1]**2 + _jab_ref[:, ii, 2]**2)
_hti = _ht.copy()
_hri = _hr.copy()
#renormalize jabtii using jabrii:
