def _hue_bin_data_to_rg(hue_bin_data):
jabt_closed = np.vstack(
(hue_bin_data['jabt_hj'], hue_bin_data['jabt_hj'][:1, ...]))
jabr_closed = np.vstack(
(hue_bin_data['jabr_hj'], hue_bin_data['jabr_hj'][:1, ...]))
notnan_t = np.logical_not(np.isnan(
jabt_closed[..., 1])) # avoid NaN's (i.e. empty hue-bins)
notnan_r = np.logical_not(np.isnan(jabr_closed[..., 1]))
Rg = np.array([[
100 * _polyarea(jabt_closed[notnan_t[:, i], i, 1],
jabt_closed[notnan_t[:, i], i, 2]) /
_polyarea(jabr_closed[notnan_r[:, i], i, 1],
jabr_closed[notnan_r[:, i], i, 2])
for i in range(notnan_r.shape[-1])
]])
return Rg
def add_to_cmf_dict(bar=None, cieobs='indv', K=683, M=np.eye(3)):
"""
Add set of cmfs to _CMF dict.
Args:
:bar:
| None, optional
| Set of CMFs. None: initializes to empty ndarray.
:cieobs:
| 'indv' or str, optional
| Name of CMF set.
:K:
| 683 (lm/W), optional
| Conversion factor from radiometric to photometric quantity.
:M:
| np.eye, optional
| Matrix for lms to xyz conversion.
"""
if bar is None:
wl3 = getwlr(_WL3)
bar = np.vstack((wl3, np.empty((3, wl3.shape[0]))))
_CMF['types'].append(cieobs)
_CMF[cieobs] = {'bar': bar}
_CMF[cieobs]['K'] = K
_CMF[cieobs]['M'] = M
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 blackbody(cct, wl3 = None, n = None):
"""
Calculate blackbody radiator spectrum for correlated color temperature (cct).
Args:
:cct:
| int or float
| (for list of cct values, use cri_ref() with ref_type = 'BB')
:wl3:
| None, optional
| New wavelength range for interpolation.
| Defaults to wavelengths specified by luxpy._WL3.
:n:
| None, optional
| Refractive index.
| If None: use the one stored in _BB['n']
Returns:
:returns:
| ndarray with blackbody radiator spectrum
| (:returns:[0] contains wavelengths)
References:
1. `CIE15:2018, “Colorimetry,” CIE, Vienna, Austria, 2018. <https://doi.org/10.25039/TR.015.2018>`_
"""
cct = float(cct)
if wl3 is None: wl3 = _WL3
if n is None: n = _BB['n']
wl = getwlr(wl3)
def fSr(x):
return (1/np.pi)*_BB['c1']*((x*1.0e-9)**(-5))*(n**(-2.0))*(np.exp(_BB['c2']*((n*x*1.0e-9*(cct+_EPS))**(-1.0)))-1.0)**(-1.0)
return np.vstack((wl,(fSr(wl)/fSr(560.0))))
def _plot_target_vs_predicted_lab(labtarget, labpredicted, cspace = 'lab', verbosity = 1):
""" Make a plot of target vs predicted color coordinates """
if verbosity > 0:
xylabels = _CSPACE_AXES[cspace]
laball = np.vstack((labtarget,labpredicted))
ml,ma,mb = laball.min(axis=0)
Ml,Ma,Mb = laball.max(axis=0)
fml = 0.95*ml
fMl = 1.05*Ml
fma = 1.05*ma if ma < 0 else 0.95*ma
fMa = 0.95*Ma if Ma < 0 else 1.05*Ma
fmb = 1.05*mb if mb < 0 else 0.95*mb
fMb = 0.95*Mb if Mb < 0 else 1.05*Mb
fig,(ax0,ax1,ax2) = plt.subplots(nrows=1,ncols=3, figsize = (15,4))
ax0.plot(labtarget[...,1],labtarget[...,2],'bo',label = 'target')
ax0.plot(labpredicted[...,1],labpredicted[...,2],'ro',label = 'predicted')
ax0.axis([fma,fMa,fmb,fMb])
ax1.plot(labtarget[...,1],labtarget[...,0],'bo',label = 'target')
ax1.plot(labpredicted[...,1],labpredicted[...,0],'ro',label = 'predicted')
ax1.axis([fma,fMa,fml,fMl])
ax2.plot(labtarget[...,2],labtarget[...,0],'bo',label = 'target')
ax2.plot(labpredicted[...,2],labpredicted[...,0],'ro',label = 'predicted')
ax2.axis([fmb,fMb,fml,fMl])
ax0.set_xlabel(xylabels[1])
ax0.set_ylabel(xylabels[2])
ax1.set_xlabel(xylabels[1])
ax1.set_ylabel(xylabels[0])
ax2.set_xlabel(xylabels[2])
ax2.set_ylabel(xylabels[0])
ax2.legend(loc='upper left')
def _complete_ldt_lid(LDT, Isym=4):
"""
Convert LDT LID map with Isym symmetry to a 'full' map with phi: [0,360] and theta: [0,180].
"""
cangles = LDT['h_angs']
tangles = LDT['v_angs']
candela_2d = LDT['candela_2d']
if Isym == 4:
# complete cangles:
a = candela_2d.copy().T
b = np.hstack((a, a[:, (a.shape[1] - 2)::-1]))
c = np.hstack((b, b[:, (b.shape[1] - 2):0:-1]))
candela_2d_0C360 = np.hstack((c, c[:, :1]))
cangles = np.hstack(
(cangles, cangles[1:] + 90, cangles[1:] + 180, cangles[1:] + 270))
# complete tangles:
a = candela_2d_0C360.copy()
b = np.vstack((a, np.zeros(a.shape)[1:, :]))
tangles = np.hstack((tangles, tangles[1:] + 90))
candela_2d = b
elif Isym == -4:
# complete cangles:
a = candela_2d.copy().T
b = np.hstack((a, a[:, (a.shape[1] - 2)::-1]))
c = np.hstack((b, b[:, (b.shape[1] - 2):0:-1]))
candela_2d_0C360 = np.hstack((c, c[:, :1]))
cangles = np.hstack(
(cangles, -cangles[(cangles.shape[0] - 2)::-1] + 180))
cangles = np.hstack(
(cangles, -cangles[(cangles.shape[0] - 2):0:-1] + 360))
cangles = np.hstack((cangles, cangles[:1]))
# complete tangles:
a = candela_2d_0C360.copy()
b = np.vstack((a, np.zeros(a.shape)[1:, :]))
tangles = np.hstack(
(tangles, -tangles[(tangles.shape[0] - 2)::-1] + 180))
candela_2d = b
else:
raise Exception(
'complete_ldt_lid(): Other "Isym" than "4", not yet implemented (31/10/2018).'
)
LDT['map'] = {'thetas': tangles}
LDT['map']['phis'] = cangles
LDT['map']['values'] = candela_2d.T
return LDT
def plotceruleanline(cieobs=_CIEOBS,
cspace=_CSPACE,
axh=None,
formatstr='ko-',
cspace_pars={}):
"""
Plot cerulean (yellow (577 nm) - blue (472 nm)) line
| Kuehni, CRA, 2014:
| Table II: spectral lights.
Args:
:axh:
| None or axes handle, optional
| Determines axes to plot data in.
| None: make new figure.
:cieobs:
| luxpy._CIEOBS or str, optional
| Determines CMF set to calculate spectrum locus or other.
:cspace:
| luxpy._CSPACE or str, optional
| Determines color space / chromaticity diagram to plot data in.
| Note that data is expected to be in specified :cspace:
:formatstr:
| 'k-' or str, optional
| Format str for plotting (see ?matplotlib.pyplot.plot)
:cspace_pars:
| {} or dict, optional
| Dict with parameters required by color space specified in :cspace:
| (for use with luxpy.colortf())
:kwargs:
| additional keyword arguments for use with matplotlib.pyplot.
Returns:
:returns:
| handle to cerulean line
References:
1. `Kuehni, R. G. (2014).
Unique hues and their stimuli—state of the art.
Color Research & Application, 39(3), 279–287.
<https://doi.org/10.1002/col.21793>`_
(see Table II, IV)
"""
if isinstance(cieobs, str):
cmf = _CMF[cieobs]['bar']
else:
cmf = cieobs
p_y = cmf[0] == 577.0 #Kuehni, CRA 2013 (mean, table IV)
p_b = cmf[0] == 472.0 #Kuehni, CRA 2013 (mean, table IV)
xyz_y = cmf[1:, p_y].T
xyz_b = cmf[1:, p_b].T
lab = colortf(np.vstack((xyz_b, xyz_y)), tf=cspace, tfa0=cspace_pars)
if axh is None:
axh = plt.gca()
hcerline = axh.plot(lab[:, 1], lab[:, 2], formatstr, label='Cerulean line')
return hcerline
def normalize_to_Lw(Ill, Lw, cieobs, rflM):
xyzw = lx.spd_to_xyz(Ill, cieobs=cieobs, relative=False)
for i in range(Ill.shape[0] - 1):
Ill[i + 1] = Lw * Ill[i + 1] / xyzw[i, 1]
IllM = []
for i in range(Ill.shape[0] - 1):
IllM.append(np.vstack((Ill1[0], Ill[i + 1] * rflM[1:, :])))
IllM = np.transpose(np.array(IllM), (1, 0, 2))
return Ill, IllM
def hsi_to_rgb(hsi,
spd=None,
cieobs=_CIEOBS,
srgb=False,
linear_rgb=False,
CSF=None,
wl=[380, 780, 1]):
"""
Convert HyperSpectral Image to rgb.
Args:
:hsi:
| ndarray with hyperspectral image [M,N,L]
:spd:
| None, optional
| ndarray with illumination spectrum
:cieobs:
| _CIEOBS, optional
| CMF set to convert spectral data to xyz tristimulus values.
:srgb:
| False, optional
| If False: Use xyz_to_srgb(spd_to_xyz(...)) to convert to srgb values
| If True: use camera sensitivity functions.
:linear_rgb:
| False, optional
| If False: use gamma = 2.4 in xyz_to_srgb, if False: use gamma = 1.
:CSF:
| None, optional
| ndarray with camera sensitivity functions
| If None: use Nikon D700
:wl:
| [380,780,1], optional
| Wavelength range and spacing or ndarray with wavelengths of HSI image.
Returns:
:rgb:
| ndarray with rgb image [M,N,3]
"""
if spd is None:
spd = _CIE_E.copy()
wlr = getwlr(wl)
spd = cie_interp(spd, wl, kind='linear')
hsi_2d = np.reshape(hsi, (hsi.shape[0] * hsi.shape[1], hsi.shape[2]))
if srgb:
xyz = spd_to_xyz(spd,
cieobs=cieobs,
relative=True,
rfl=np.vstack((wlr, hsi_2d)))
gamma = 1 if linear_rgb else 2.4
rgb = xyz_to_srgb(xyz, gamma=gamma) / 255
else:
if CSF is None: CSF = _CSF_NIKON_D700
rgb = rfl_to_rgb(hsi_2d, spd=spd, CSF=CSF, wl=wl)
return np.reshape(rgb, (hsi.shape[0], hsi.shape[1], 3))
def spdBB(CCT=5500, wl=[400, 700, 5], Lw=25000, cieobs='1964_10'):
wl = getwlr(wl)
dl = wl[1] - wl[0]
spd = 2 * np.pi * 6.626068E-34 * (299792458**2) / (
(wl * 0.000000001)**
5) / (np.exp(6.626068E-34 * 299792458 /
(wl * 0.000000001) / 1.3806503E-23 / CCT) - 1)
spd = Lw * spd / (dl * 683 * (spd * cie_interp(
_CMF[cieobs]['bar'].copy(), wl, kind='cmf')[2, :]).sum())
return np.vstack((wl, spd))
def _cri_ref_i(cct,
wl3=_WL,
ref_type='iestm30',
mix_range=[4000, 5000],
cieobs='1931_2',
force_daylight_below4000K=False,
n=None,
daylight_locus=None):
"""
Calculates a reference illuminant spectrum based on cct
for color rendering index calculations.
"""
if mix_range is None:
mix_range = _CRI_REF_TYPES[ref_type]
if (cct < mix_range[0]) | (ref_type == 'BB'):
return blackbody(cct, wl3, n=n)
elif (cct > mix_range[0]) | (ref_type == 'DL'):
return daylightphase(
cct,
wl3,
force_daylight_below4000K=force_daylight_below4000K,
cieobs=cieobs,
daylight_locus=daylight_locus)
else:
SrBB = blackbody(cct, wl3, n=n)
SrDL = daylightphase(
cct,
wl3,
verbosity=None,
force_daylight_below4000K=force_daylight_below4000K,
cieobs=cieobs,
daylight_locus=daylight_locus)
cmf = _CMF[cieobs]['bar'] if isinstance(cieobs, str) else cieobs
wl = SrBB[0]
ld = getwld(wl)
SrBB = 100.0 * SrBB[1] / np.array(np.sum(SrBB[1] * cmf[2] * ld))
SrDL = 100.0 * SrDL[1] / np.array(np.sum(SrDL[1] * cmf[2] * ld))
Tb, Te = float(mix_range[0]), float(mix_range[1])
cBB, cDL = (Te - cct) / (Te - Tb), (cct - Tb) / (Te - Tb)
if cBB < 0.0:
cBB = 0.0
elif cBB > 1:
cBB = 1.0
if cDL < 0.0:
cDL = 0.0
elif cDL > 1:
cDL = 1.0
Sr = SrBB * cBB + SrDL * cDL
Sr[Sr == float('NaN')] = 0.0
Sr = np.vstack((wl, (Sr / Sr[_POS_WL560])))
return Sr
def _rgb_delinearizer(rgblin, tr, tr_type = 'lut'):
""" De-linearize linear rgblin using tr tone response function or lut """
if tr_type == 'gog':
return np.array([TRi(rgblin[:,i],*tr[i]) for i in range(3)]).T
elif tr_type == 'lut':
maxv = (tr.shape[0] - 1)
bins = np.vstack((tr-np.diff(tr,axis=0,prepend=0)/2,tr[-1,:]+0.01)) # create bins
idxs = np.array([(np.digitize(rgblin[:,i],bins[:,i]) - 1) for i in range(3)]).T # find bin indices
idxs[idxs>maxv] = maxv
rgb = np.arange(tr.shape[0])[idxs]
return rgb
def interpolate_efficiency_functions(wl, cs_cl_lrs):
"""
Interpolate all spectral data in dict cs_cl_lrs to new wavelength range.
"""
for key in cs_cl_lrs:
if key[-1] == 'l': #signifies l for spectral data
temp = np.vstack((cs_cl_lrs['WL'],cs_cl_lrs[key])) # construct [wl,S] data
cs_cl_lrs[key] = cie_interp(temp,wl, kind = 'cmf', negative_values_allowed=True)[1:] # interpolate and store in dict
cs_cl_lrs['WL'] = wl # store new wavelength range
return cs_cl_lrs
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 lmsb_to_xyzb(lms, fieldsize=10, out='XYZ', allow_negative_values=False):
"""
Convert from LMS cone fundamentals to XYZ color matching functions.
Args:
:lms:
| ndarray with lms cone fundamentals, optional
:fieldsize:
| fieldsize in degrees, optional
| Defaults to 10°.
:out:
| 'xyz' or str, optional
| Determines output.
:allow_negative_values:
| False, optional
| XYZ color matching functions should not have negative values.
| If False: xyz[xyz<0] = 0.
Returns:
:returns:
| LMS
| - LMS: ndarray with population XYZ color matching functions.
Note:
For intermediate field sizes (2° < fieldsize < 10°) a conversion matrix
is calculated by linear interpolation between
the _INDVCMF_M_2d and _INDVCMF_M_10d matrices.
"""
wl = lms[None, 0] #store wavelengths
M = get_lms_to_xyz_matrix(fieldsize=fieldsize)
if lms.ndim > 2:
xyz = np.vstack((wl, math.dot23(M, lms[1:, ...], keepdims=False)))
else:
xyz = np.vstack((wl, np.dot(M, lms[1:, ...])))
if allow_negative_values == False:
xyz[np.where(xyz < 0)] = 0
return xyz
def crowdingdistance(F):
"""
Computes the crowding distance of a nondominated front.
| The crowding distance gives a measure of how close the individuals are
| with regard to its neighbors. The higher this value, the greater the
| spacing. This is used to promote better diversity in the population.
Args:
:F:
| an m x mu ndarray with mu individuals and m objectives
Returns:
:cdist:
| a m-length column vector
"""
m, mu = F.shape #gets the size of F
if mu == 2:
cdist = np.vstack((np.inf, np.inf))
return cdist
#[Fs, Is] = sort(F,2); #sorts the objectives by individuals
Is = F.argsort(axis = 1)
Fs = np.sort(F,axis=1)
# Creates the numerator
C = Fs[:,2:] - Fs[:,:-2]
C = np.hstack((np.inf*np.ones((m,1)), C, np.inf*np.ones((m,1)))) #complements with inf in the extremes
# Indexing to permute the C matrix in the right ordering
Aux = np.arange(m).repeat(mu).reshape(m,mu)
ind = np.ravel_multi_index((Aux.flatten(),Is.flatten()),(m, mu)) #converts to lin. indexes # ind = sub2ind([m, mu], Aux(:), Is(:));
C2 = C.flatten().copy()
C2[ind] = C2.flatten()
C = C2.reshape((m, mu))
# Constructs the denominator
den = np.repeat((Fs[:,-1] - Fs[:,0])[:,None], mu, axis = 1)
# Calculates the crowding distance
cdist = (C/den).sum(axis=0)
cdist = cdist.flatten() #assures a column vector
return cdist
def _get_distance_matrix_grouping(*X, metric='euclidean', Dscale=1):
""" Get distance matrix (skbio format) and grouping indexing array from raw data"""
# Create long format data array and grouping indices:
ni = np.empty((len(X), ), dtype=int)
for i, Xi in enumerate(X):
ni[i] = Xi.shape[0]
if i == 0:
XY = Xi
else:
XY = np.vstack((XY, Xi))
grouping = [[i] * n for i, n in enumerate(ni)]
grouping = list(itertools.chain(*grouping))
# Calculate pairwise distances:
D = scipy.spatial.distance.pdist(XY, metric=metric) * Dscale
Dsq = scipy.spatial.distance.squareform(D)
# Get skbio distance matrix:
Dm = skbio.stats.distance.DistanceMatrix(Dsq)
return Dm, grouping
def rgb_to_spec_smits(rgb, intent='rfl', bitdepth=8, wlr=_WL3, rgb2spec=None):
"""
Convert an array of RGB values to a spectrum using a Smits like conversion as implemented in Mitsuba.
Args:
:rgb:
| ndarray of list of rgb values
:intent:
| 'rfl' (or 'spd'), optional
| type of requested spectrum conversion .
:bitdepth:
| 8, optional
| bit depth of rgb values
:wlr:
| _WL3, optional
| desired wavelength (nm) range of spectrum.
:rgb2spec:
| None, optional
| Dict with base spectra for white, cyan, magenta, yellow, blue, green and red for each intent.
| If None: use _BASESPEC_SMITS.
Returns:
:spec:
| ndarray with spectrum or spectra (one for each rgb value, first row are the wavelengths)
"""
if isinstance(rgb, list):
rgb = np.atleast_2d(rgb)
if rgb.max() > 1:
rgb = rgb / (2**bitdepth - 1)
if rgb2spec is None:
rgb2spec = _BASESPEC_SMITS
if not np.array_equal(rgb2spec['wlr'], getwlr(wlr)):
rgb2spec = _convert_to_wlr(entries=copy.deepcopy(rgb2spec), wlr=wlr)
spec = np.zeros((rgb.shape[0], rgb2spec['wlr'].shape[0]))
for i in range(rgb.shape[0]):
spec[i, :] = _fromLinearRGB(rgb[i, :],
intent=intent,
rgb2spec=rgb2spec,
wlr=wlr)
return np.vstack((rgb2spec['wlr'], spec))
def dtlz_range(fname, M):
"""
Returns the decision range of a DTLZ function
| The range is simply [0,1] for all variables. What varies is the number
| of decision variables in each problem. The equation for that is
| n = (M-1) + k
| wherein k = 5 for DTLZ1, 10 for DTLZ2-6, and 20 for DTLZ7.
Args:
:fname:
| a string with the name of the function ('dtlz1', 'dtlz2' etc.)
:M:
| a scalar with the number of objectives
Returns:
:lim:
| a 2 x n matrix wherein the first row is the lower limit
| (0), and the second row, the upper limit of search (1)
"""
#Checks if the string has or not the prefix 'dtlz', or if the number later
#is greater than 7:
fname = fname.lower()
if (len(fname) < 5) or (fname[:4] != 'dtlz') or (float(fname[4]) > 7) :
raise Exception('Sorry, the function {:s} is not implemented.'.format(fname))
# If the name is o.k., defines the value of k
if fname == 'dtlz1':
k = 5
elif fname == 'dtlz7':
k = 20
else: #any other function
k = 10;
n = (M-1) + k #number of decision variables
lim = np.vstack((np.zeros((1,n)), np.ones((1,n))))
return lim
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 _simple_cam(
data,
dataw=None,
Lw=100.0,
relative=True,
inputtype='xyz',
direction='forward',
cie_illuminant='D65',
parameters={
'cA': 1,
'ca': np.array([1, -1, 0]),
'cb': (1 / 3) * np.array([0.5, 0.5, -1]),
'n': 1 / 3,
'Mxyz2lms': _CMF['1931_2']['M'].copy()
},
cieobs='2006_10',
match_to_conversionmatrix_to_cieobs=True):
"""
An example CAM illustration the usage of the functions in luxpy.cam.helpers
| Note that this example uses NO chromatic adaptation
| and SIMPLE compression, opponent and correlate processing.
| THIS IS ONLY FOR ILLUSTRATION PURPOSES !!!
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:
:cie_illuminant:
| 'D65', optional
| String corresponding to one of the illuminants (keys)
| in luxpy._CIE_ILLUMINANT
| If ndarray, then use this one.
| This is ONLY USED WHEN dataw is NONE !!!
:Lw:
| 100.0, optional
| Luminance (cd/m²) of white point.
:relative:
| True or False, optional
| True: data and dataw input is relative (i.e. Yw = 100)
:parameters:
| {'cA': 1, 'ca':np.array([1,-1,0]), 'cb':(1/3)*np.array([0.5,0.5,-1]),
| 'n': 1/3, 'Mxyz2lms': _CMF['1931_2']['M'].copy()}
| Dict with model parameters
| (For illustration purposes of match_conversionmatrix_to_cieobs,
| the conversion matrix luxpy._CMF['1931_2']['M'] does NOT match
| the default observer specification of the input data in :cieobs: !!!)
:inputtype:
| 'xyz' or 'spd', optional
| Specifies the type of input:
| tristimulus values or spectral data for the forward mode.
:direction:
| 'forward' or 'inverse', optional
| -'forward': xyz -> cam
| -'inverse': cam -> xyz
: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']
:match_conversionmatrix_to_cieobs:
| True, optional
| When changing to a different CIE observer, change the xyz_to_lms
| matrix to the one corresponding to that observer.
| Set to False to keep the one in the parameter dict!
Returns:
:returns:
| ndarray with:
| - color appearance correlates (:direction: == 'forward')
| or
| - XYZ tristimulus values (:direction: == 'inverse')
"""
#--------------------------------------------------------------------------
# Get model parameters:
#--------------------------------------------------------------------------
args = locals().copy(
) # gets all local variables (i.e. the function arguments)
parameters = _update_parameter_dict(
args,
parameters=parameters,
cieobs=cieobs,
match_conversionmatrix_to_cieobs=match_to_conversionmatrix_to_cieobs,
Mxyz2lms_whitepoint=np.array([[1, 1, 1]]))
#unpack model parameters:
(Mxyz2lms, cA, ca, cb,
n) = [parameters[x] for x in sorted(parameters.keys())]
#--------------------------------------------------------------------------
# Setup default white point / adaptation field:
#--------------------------------------------------------------------------
dataw = _setup_default_adaptation_field(dataw=dataw,
Lw=Lw,
cie_illuminant='C',
inputtype=inputtype,
relative=relative,
cieobs=cieobs)
#--------------------------------------------------------------------------
# Redimension input data to ensure most appropriate sizes
# for easy and efficient looping and initialize output array:
#--------------------------------------------------------------------------
n_out = 5 # this example outputs 5 'correlates': J, a, b, C, h
(data, dataw, camout,
originalshape) = _massage_input_and_init_output(data,
dataw,
inputtype=inputtype,
direction=direction,
n_out=n_out)
#--------------------------------------------------------------------------
# Do precomputations needed for both the forward and inverse model,
# and which do not depend on sample or light source data:
#--------------------------------------------------------------------------
# Create matrix with scale factors for L, M, S
# for quick matrix multiplications to obtain neural signals:
MAab = np.array([[cA, cA, cA], ca, cb])
if direction == 'inverse':
invMxyz2lms = np.linalg.inv(
Mxyz2lms) # Calculate the inverse lms-to-xyz conversion matrix
invMAab = np.linalg.inv(
MAab) # Pre-calculate its inverse to avoid repeat in loop.
#--------------------------------------------------------------------------
# Apply forward/inverse model by looping over each row (=light source dim.)
# in data:
#--------------------------------------------------------------------------
N = data.shape[0]
for i in range(N):
#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# START FORWARD MODE and common part of inverse mode
#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
#-----------------------------------------------------------------------------
# Get tristimulus values for stimulus field and white point for row i:
#-----------------------------------------------------------------------------
# Note that xyzt will contain a None in case of inverse mode !!!
xyzt, xyzw, xyzw_abs = _get_absolute_xyz_xyzw(data,
dataw,
i=i,
Lw=Lw,
direction=direction,
cieobs=cieobs,
inputtype=inputtype,
relative=relative)
#---------------------------------------------------------------------
# stage 1 (white point): calculate lms values of white:
#----------------------------------------------------------------------
lmsw = np.dot(Mxyz2lms, xyzw.T).T
#------------------------------------------------------------------
# stage 2 (white): apply simple chromatic adaptation:
#------------------------------------------------------------------
lmsw_a = lmsw / lmsw
#----------------------------------------------------------------------
# stage 3 (white point): apply simple compression to lms values
#----------------------------------------------------------------------
lmsw_ac = lmsw_a**n
#----------------------------------------------------------------------
# stage 4 (white point): calculate achromatic A, and opponent signals a,b):
#----------------------------------------------------------------------
Aabw = np.dot(MAab, lmsw_ac.T).T
#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
# SPLIT CALCULATION STEPS IN FORWARD AND INVERSE MODES:
#++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
if direction == 'forward':
#------------------------------------------------------------------
# stage 1 (stimulus): calculate lms values
#------------------------------------------------------------------
lms = np.dot(Mxyz2lms, xyzt.T).T
#------------------------------------------------------------------
# stage 2 (stimulus): apply simple chromatic adaptation:
#------------------------------------------------------------------
lms_a = lms / lmsw
#------------------------------------------------------------------
# stage 3 (stimulus): apply simple compression to lms values
#------------------------------------------------------------------
lms_ac = lms_a**n
#------------------------------------------------------------------
# stage 3 (stimulus): calculate achromatic A, and opponent signals a,b:
#------------------------------------------------------------------
Aab = np.dot(MAab, lms_ac.T).T
#------------------------------------------------------------------
# stage 4 (stimulus): calculate J, C, h
#------------------------------------------------------------------
J = Aab[..., 0] / Aabw[..., 0]
C = (Aab[..., 1]**2 + Aab[..., 2]**2)**0.5
h = math.positive_arctan(Aab[..., 1], Aab[..., 2])
# # stack together:
camout[i] = np.vstack((J, Aab[..., 1], Aab[..., 2], C, h)).T
#--------------------------------------
# INVERSE MODE FROM PERCEPTUAL SIGNALS:
#--------------------------------------
elif direction == 'inverse':
pass
return _massage_output_data_to_original_shape(camout, originalshape)
if __name__ == '__main__':
#--------------------------------------------------------------------------
# Code test
#--------------------------------------------------------------------------
import luxpy as lx
from luxpy import np
# Prepare some illuminant data:
C = _CIE_ILLUMINANTS['C'].copy()
Ill1 = C
Ill2 = np.vstack(
(C, lx.cie_interp(_CIE_ILLUMINANTS['D65'], C[0],
kind='spd')[1:], C[1:, :] * 2, C[1:, :] * 3))
# Prepare some sample data:
rflM = lx._MUNSELL['R'].copy()
rflM = lx.cie_interp(rflM, C[0], kind='rfl')
# Setup some model parameters:
cieobs = '2006_10'
Lw = 400
# Create Lw normalized data:
# Normalize to Lw:
def normalize_to_Lw(Ill, Lw, cieobs, rflM):
xyzw = lx.spd_to_xyz(Ill, cieobs=cieobs, relative=False)
for i in range(Ill.shape[0] - 1):
def _massage_input_and_init_output(data,
dataw,
inputtype='xyz',
direction='forward',
n_out=3):
"""
Redimension input data to ensure most they have the appropriate sizes for easy and efficient looping.
|
| 1. Convert data and dataw to atleast_2d ndarrays
| 2. Make axis 1 of dataw have 'same' dimensions as data
| 3. Make dataw have same lights source axis size as data
| 4. Flip light source axis to axis=0 for efficient looping
| 5. Initialize output array camout to 'same' shape as data but with camout.shape[-1] == n_out
Args:
:data:
| ndarray with input tristimulus values
| or spectral data
| or input color appearance correlates
| Can be of shape: (N [, xM], x 3), whereby:
| N refers to samples and M refers to light sources.
| Note that for spectral input shape is (N x (M+1) x wl)
:dataw:
| None or ndarray, optional
| Input tristimulus values or spectral data of white point.
| None defaults to the use of CIE illuminant C.
:inputtype:
| 'xyz' or 'spd', optional
| Specifies the type of input:
| tristimulus values or spectral data for the forward mode.
:direction:
| 'forward' or 'inverse', optional
| -'forward': xyz -> cam
| -'inverse': cam -> xyz
:n_out:
| 3, optional
| output size of last dimension of camout
| (e.g. n_out=3 for j,a,b output or n_out = 5 for J,M,h,a,b output)
Returns:
:data:
| ndarray with reshaped data
:dataw:
| ndarray with reshaped dataw
:camout:
| NaN filled ndarray for output of CAMv (camout.shape[-1] == Nout)
:originalshape:
| original shape of data
Notes:
For an example on the use, see code _simple_cam() (type: _simple_cam??)
"""
# Convert data and dataw to atleast_2d ndarrays:
data = np2d(data).copy(
) # stimulus data (can be upto NxMx3 for xyz, or [N x (M+1) x wl] for spd))
dataw = np2d(dataw).copy(
) # white point (can be upto Nx3 for xyz, or [(N+1) x wl] for spd)
originalshape = data.shape # to restore output to same shape
# Make axis 1 of dataw have 'same' dimensions as data:
if (data.ndim == 2):
data = np.expand_dims(data, axis=1) # add light source axis 1
# Flip light source dim to axis 0:
data = np.transpose(data, axes=(1, 0, 2))
dataw = np.expand_dims(
dataw, axis=1) # add extra axis to move light source to axis 0
# Make dataw have same lights source dimension size as data:
if inputtype == 'xyz':
if dataw.shape[0] == 1:
dataw = np.repeat(dataw, data.shape[0], axis=0)
if (data.shape[0] == 1) & (dataw.shape[0] > 1):
data = np.repeat(data, dataw.shape[0], axis=0)
else:
dataw = np.array([
np.vstack((dataw[:1, 0, :], dataw[i + 1:i + 2, 0, :]))
for i in range(dataw.shape[0] - 1)
])
if (data.shape[0] == 1) & (dataw.shape[0] > 1):
data = np.repeat(data, dataw.shape[0], axis=0)
# Initialize output array:
if n_out is not None:
dshape = list((data).shape)
dshape[-1] = n_out # requested number of correlates: e.g. j,a,b
if (inputtype != 'xyz') & (direction == 'forward'):
dshape[-2] = dshape[
-2] - 1 # wavelength row doesn't count & only with forward can the input data be spectral
camout = np.zeros(dshape)
camout.fill(np.nan)
else:
camout = None
return data, dataw, camout, originalshape
def 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.zeros((len(dataVF), 1))
delta_SvsVF_vshift_ab_mean.fill(np.nan)
delta_SvsVF_vshift_ab_mean_normalized = delta_SvsVF_vshift_ab_mean.copy()
delta_PXvsVF_vshift_ab_mean = np.zeros((len(dataVF), 1))
delta_PXvsVF_vshift_ab_mean.fill(np.nan)
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 subsample_RFL_set(rfl, rflpath = '', samplefcn = 'rand', S = _CIE_ILLUMINANTS['E'], \
jab_ranges = None, jab_deltas = None, cieobs = _VF_CIEOBS, cspace = _VF_CSPACE, \
ax = np.arange(-_VF_MAXR,_VF_MAXR+_VF_DELTAR,_VF_DELTAR), \
bx = np.arange(-_VF_MAXR,_VF_MAXR+_VF_DELTAR,_VF_DELTAR), \
jx = None, limit_grid_radius = 0):
"""
Sub-samples a spectral reflectance set by pixelization of color space.
Args:
:rfl:
| ndarray or str
| Array with of str referring to a set of spectral reflectance
| functions to be subsampled.
| If str to file: file must contain data as columns, with first
| column the wavelengths.
:rflpath:
| '' or str, optional
| Path to folder with rfl-set specified in a str :rfl: filename.
:samplefcn:
| 'rand' or 'mean', optional
| -'rand': selects a random sample from the samples within each pixel
| -'mean': returns the mean spectral reflectance in each pixel.
:S:
| _CIE_ILLUMINANTS['E'], optional
| Illuminant used to calculate the color coordinates of the spectral
| reflectance samples.
: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.
:cspace:
| _VF_CSPACE or dict, optional
| Specifies color space. See _VF_CSPACE_EXAMPLE for example structure.
:cieobs:
| _VF_CIEOBS or str, optional
| Specifies CMF set used to calculate color coordinates.
:ax:
| default ndarray or user defined ndarray, optional
| default = np.arange(-_VF_MAXR,_VF_MAXR+_VF_DELTAR,_VF_DELTAR)
:bx:
| default ndarray or user defined ndarray, optional
| default = np.arange(-_VF_MAXR,_VF_MAXR+_VF_DELTAR,_VF_DELTAR)
:jx:
| None, optional
| Note that not-None :jab_ranges: override :ax:, :bx: and :jx input.
: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:
| rflsampled, jabp
| ndarrays with resp. the subsampled set of spectral reflectance
| functions and the pixel coordinate centers.
"""
# Testing effects of sample set, pixel size and gamut size:
if type(rfl) == str:
rfl = pd.read_csv(os.path.join(rflpath, rfl),
header=None).get_values().T
# Calculate Jab coordinates of samples:
xyz, xyzw = spd_to_xyz(S, cieobs=cieobs, rfl=rfl.copy(), out=2)
cspace_pars = cspace.copy()
cspace_pars.pop('type')
cspace_pars['xyzw'] = xyzw
jab = colortf(xyz, tf=cspace['type'], fwtf=cspace_pars)
# Generate grid and get samples in each grid:
gridp, idxp, jabp, pixelsamplenrs, pixelIDs = get_pixel_coordinates(
jab,
jab_ranges=jab_ranges,
jab_deltas=jab_deltas,
limit_grid_radius=limit_grid_radius)
# Get rfls from set using sampling function (mean or rand):
W = rfl[:1]
R = rfl[1:]
rflsampled = np.zeros((len(idxp), R.shape[1]))
rflsampled.fill(np.nan)
for i in range(len(idxp)):
if samplefcn == 'mean':
rfl_i = np.nanmean(rfl[pixelsamplenrs[i], :], axis=0)
else:
samplenr_i = np.random.randint(len(pixelsamplenrs[i]))
rfl_i = rfl[pixelsamplenrs[i][samplenr_i], :]
rflsampled[i, :] = rfl_i
rflsampled = np.vstack((W, rflsampled))
return rflsampled, jabp
def xyz_to_rfl(xyz, CSF = None, rfl = None, out = 'rfl_est', \
refspd = None, D = None, cieobs = _CIEOBS, \
cspace = 'xyz', cspace_tf = {},\
interp_type = 'nd', k_neighbours = 4, verbosity = 0):
"""
Approximate spectral reflectance of xyz values based on nd-dimensional linear interpolation
or k nearest neighbour interpolation of samples from a standard reflectance set.
Args:
:xyz:
| ndarray with xyz values of target points.
:CSF:
| None, optional
| RGB camera response functions.
| If None: input :xyz: contains raw rgb (float) values. Override :cspace:
| argument and perform estimation directly in raw rgb space!!!
:rfl:
| ndarray, optional
| Reflectance set for color coordinate to rfl mapping.
:out:
| 'rfl_est' or str, optional
:refspd:
| None, optional
| Refer ence spectrum for color coordinate to rfl mapping.
| None defaults to D65.
:cieobs:
| _CIEOBS, optional
| CMF set used for calculation of xyz from spectral data.
:cspace:
| 'xyz', optional
| Color space for color coordinate to rfl mapping.
| Tip: Use linear space (e.g. 'xyz', 'Yuv',...) for (interp_type == 'nd'),
| and perceptually uniform space (e.g. 'ipt') for (interp_type == 'nearest')
:cspace_tf:
| {}, optional
| Dict with parameters for xyz_to_cspace and cspace_to_xyz transform.
:interp_type:
| 'nd', optional
| Options:
| - 'nd': perform n-dimensional linear interpolation using Delaunay triangulation.
| - 'nearest': perform nearest neighbour interpolation.
:k_neighbours:
| 4 or int, optional
| Number of nearest neighbours for reflectance spectrum interpolation.
| Neighbours are found using scipy.spatial.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']
wlr = rfl[0]
# get Ref spd:
if refspd is None:
refspd = _CIE_ILLUMINANTS['D65'].copy()
refspd = cie_interp(
refspd, wlr,
kind='linear') # force spd to same wavelength range as rfl
# Calculate rgb values of standard rfl set under refspd:
if CSF is None:
# Calculate lab coordinates:
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, :]
else:
# Calculate rgb coordinates from camera sensitivity functions
rgb_rr = rfl_to_rgb(rfl, spd=refspd, CSF=CSF, wl=None)
lab_rr = rgb_rr
xyz = xyz
lab_rr = np.round(lab_rr, _ROUNDING) # speed up search
# Convert xyz to lab-type values under refspd:
if CSF is None:
lab = colortf(xyz, tf=cspace, fwtf=cspace_tf_copy, bwtf=cspace_tf_copy)
else:
lab = xyz # xyz contained rgb values !!!
rgb = xyz
lab = np.round(lab, _ROUNDING) # speed up search
if interp_type == 'nearest':
# Find rfl (cfr. lab_rr) from rfl set that results in 'near' metameric
# color coordinates for each value in lab_ur (i.e. smallest DE):
# Construct cKDTree:
tree = sp.spatial.cKDTree(lab_rr, copy_data=True)
# Interpolate rfls using k nearest neightbours and inverse distance weigthing:
d, inds = tree.query(lab, k=k_neighbours)
if k_neighbours > 1:
d += _EPS
w = (1.0 / d**2)[:, :, None] # inverse distance weigthing
rfl_est = np.sum(w * rfl[inds + 1, :], axis=1) / np.sum(w, axis=1)
else:
rfl_est = rfl[inds + 1, :].copy()
elif interp_type == 'nd':
rfl_est = math.ndinterp1_scipy(lab_rr, rfl[1:], lab)
_isnan = np.isnan(rfl_est[:, 0])
if (
_isnan.any()
): #do nearest neigbour method for those that fail using Delaunay (i.e. ndinterp1_scipy)
# Find rfl (cfr. lab_rr) from rfl set that results in 'near' metameric
# color coordinates for each value in lab_ur (i.e. smallest DE):
# Construct cKDTree:
tree = sp.spatial.cKDTree(lab_rr, copy_data=True)
# Interpolate rfls using k nearest neightbours and inverse distance weigthing:
d, inds = tree.query(lab[_isnan, ...], k=k_neighbours)
if k_neighbours > 1:
d += _EPS
w = (1.0 / d**2)[:, :, None] # inverse distance weigthing
rfl_est_isnan = np.sum(w * rfl[inds + 1, :], axis=1) / np.sum(
w, axis=1)
else:
rfl_est_isnan = rfl[inds + 1, :].copy()
rfl_est[_isnan, :] = rfl_est_isnan
else:
raise Exception('xyz_to_rfl(): unsupported interp_type!')
rfl_est[
rfl_est <
0] = 0 #can occur for points outside convexhull of standard rfl set.
rfl_est = np.vstack((rfl[0], rfl_est))
if ((verbosity > 0) | ('xyz_est' in out.split(',')) |
('lab_est' in out.split(',')) | ('DEi_ab' in out.split(',')) |
('DEa_ab' in out.split(','))) & (CSF is None):
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()
elif ((verbosity > 0) | ('xyz_est' in out.split(',')) |
('rgb_est' in out.split(',')) | ('DEi_rgb' in out.split(',')) |
('DEa_rgb' in out.split(','))) & (CSF is not None):
rgb_est = rfl_to_rgb(rfl_est[1:], spd=refspd, CSF=CSF, wl=wlr)
xyz_est = rgb_est
DEi_rgb = np.sqrt(((rgb_est - rgb)**2).sum(axis=1))
DEa_rgb = DEi_rgb.mean()
if verbosity > 0:
if CSF is None:
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')
else:
n = 100 #min(rfl.shape[0]-1,rfl_est.shape[0]-1)
s = np.random.permutation(rfl.shape[0] -
1)[:min(n, rfl.shape[0] - 1)]
st = np.random.permutation(rfl_est.shape[0] -
1)[:min(n, rfl_est.shape[0] - 1)]
fig = plt.figure()
ax = np.zeros((3, ), dtype=np.object)
ax[0] = fig.add_subplot(131)
ax[1] = fig.add_subplot(132)
ax[2] = fig.add_subplot(133, projection='3d')
ax[0].plot(rfl[0], rfl[1:][s].T, linestyle='-')
ax[0].set_title('Original RFL set (random selection of all)')
ax[0].set_ylim([0, 1])
ax[1].plot(rfl_est[0], rfl_est[1:][st].T, linestyle='--')
ax[0].set_title('Estimated RFL set (random selection of targets)')
ax[1].set_ylim([0, 1])
ax[2].plot(rgb[st, 0],
rgb[st, 1],
rgb[st, 2],
'ro',
label='Original')
ax[2].plot(rgb_est[st, 0],
rgb_est[st, 1],
rgb_est[st, 2],
'bd',
label='Rendered')
ax[2].legend()
if out == 'rfl_est':
return rfl_est
elif out == 'rfl_est,xyz_est':
return rfl_est, xyz_est
else:
return eval(out)
def get_superresolution_hsi(lrhsi,
hrci,
CSF,
wl=[380, 780, 1],
interp_type='nd',
k_neighbours=4,
verbosity=0):
"""
Get a HighResolution HyperSpectral Image (super-resolution HSI) based on a LowResolution HSI and a HighResolution Color Image.
Args:
:lrhsi:
| ndarray with LowResolution HSI [m,m,L].
:hrci:
| ndarray with HighResolution HSI [M,N,3].
:CSF:
| None, optional
| ndarray with camera sensitivity functions
| If None: use Nikon D700
:wl:
| [380,780,1], optional
| Wavelength range and spacing or ndarray with wavelengths of HSI image.
:interp_type:
| 'nd', optional
| Options:
| - 'nd': perform n-dimensional linear interpolation using Delaunay triangulation.
| - 'nearest': perform nearest neighbour interpolation.
:k_neighbours:
| 4 or int, optional
| Number of nearest neighbours for reflectance spectrum interpolation.
| Neighbours are found using scipy.spatial.cKDTree
:verbosity:
| 0, optional
| Verbosity level for sub-call to render_image().
| If > 0: make a plot of the color coordinates of original and
| rendered image pixels.
Returns:
:hrhsi:
| ndarray with HighResolution HSI [M,N,L].
Procedure:
| Call render_image(hrci, rfl = lrhsi_2, CSF = ...) to estimate a hyperspectral image
| from the high-resolution color image hrci with the reflectance spectra
| in the low-resolution hyper-spectral image as database for the estimation.
| Estimation is done in raw RGB space with the lrhsi converted using the
| camera sensitivity functions in CSF.
"""
wlr = getwlr(wl)
eew = np.vstack((wlr, np.ones_like(wlr)))
lrhsi_2d = np.vstack(
(wlr,
np.reshape(lrhsi, (lrhsi.shape[0] * lrhsi.shape[1],
lrhsi.shape[2])))) # create 2D rfl database
if CSF is None: CSF = _CSF_NIKON_D700
hrhsi = render_image(
hrci,
spd=eew,
refspd=eew,
rfl=lrhsi_2d,
D=None,
interp_type=interp_type,
k_neighbours=k_neighbours,
verbosity=verbosity,
CSF=CSF) # render HR-hsi from HR-ci using LR-HSI rfls as database
return hrhsi
def spd_to_tm30(St):
"""
Calculate tm30 measures from spd.
"""
# calculate CIE 1931 2° white point xyz:
xyzw_cct, _ = spd_to_xyz(St, cieobs='1931_2', relative=True, out=2)
# calculate cct, duv:
cct, duv = xyz_to_cct(xyzw_cct, cieobs='1931_2', out='cct,duv')
# calculate ref illuminant:
Sr = _cri_ref(cct, mix_range=[4000, 5000], cieobs='1931_2', wl3=St[0])
# calculate CIE 1964 10° sample and white point xyz under test and ref. illuminants:
xyz, xyzw = spd_to_xyz(np.vstack((St, Sr[1:])),
cieobs='1964_10',
rfl=_TM30_SAMPLE_SET,
relative=True,
out=2)
N = St.shape[0] - 1
xyzt, xyzr = xyz[:, :N, :], xyz[:, N:, :]
xyzwt, xyzwr = xyzw[:N, :], xyzw[N:, :]
# calculate CAM02-UCS coordinates
# (standard conditions = {'La':100.0,'Yb':20.0,'surround':'avg','D':1.0):
jabt = _xyz_to_jab_cam02ucs(xyzt, xyzw=xyzwt)
jabr = _xyz_to_jab_cam02ucs(xyzr, xyzw=xyzwr)
# calculate DEi, Rfi:
DEi = (((jabt - jabr)**2).sum(axis=-1, keepdims=True)**0.5)[..., 0]
Rfi = log_scale(DEi, scale_factor=[6.73])
# calculate Rf
DEa = DEi.mean(axis=0, keepdims=True)
Rf = log_scale(DEa, scale_factor=[6.73])
# calculate hue-bin data:
hue_bin_data = _get_hue_bin_data(jabt, jabr, start_hue=0, nhbins=16)
# calculate Rg:
Rg = _hue_bin_data_to_rg(hue_bin_data)
# calculate local color fidelity values, Rfhj,
# local hue shift, Rhshj and local chroma shifts, Rcshj:
Rcshj, Rhshj, Rfhj, DEhj = _hue_bin_data_to_Rxhj(hue_bin_data,
scale_factor=[6.73])
# Fit ellipse to gamut shape of samples under test source:
gamut_ellipse_fit = _hue_bin_data_to_ellipsefit(hue_bin_data)
hue_bin_data['gamut_ellipse_fit'] = gamut_ellipse_fit
# return output dict:
return {
'St': St,
'Sr': Sr,
'xyzw_cct': xyzw_cct,
'xyzwt': xyzwt,
'xyzwr': xyzwr,
'xyzt': xyzt,
'xyzr': xyzr,
'cct': cct.T,
'duv': duv.T,
'jabt': jabt,
'jabr': jabr,
'DEi': DEi,
'DEa': DEa,
'Rfi': Rfi,
'Rf': Rf,
'hue_bin_data': hue_bin_data,
'Rg': Rg,
'DEhj': DEhj,
'Rfhj': Rfhj,
'Rcshj': Rcshj,
'Rhshj': Rhshj,
'hue_bin_data': hue_bin_data
}
def render_image(img = None, spd = None, rfl = None, out = 'img_hyp', \
refspd = None, D = None, cieobs = _CIEOBS, \
cspace = 'xyz', cspace_tf = {}, CSF = None,\
interp_type = 'nd', k_neighbours = 4, show = True,
verbosity = 0, show_ref_img = True,\
stack_test_ref = 12,\
write_to_file = None):
"""
Render image under specified light source spd.
Args:
:img:
| None or str or ndarray with float (max = 1) rgb image.
| None load a default image.
:spd:
| ndarray, optional
| Light source spectrum for rendering
| If None: use CIE illuminant F4
:rfl:
| ndarray, optional
| Reflectance set for color coordinate to rfl mapping.
:out:
| 'img_hyp' or str, optional
| (other option: 'img_ren': rendered image under :spd:)
:refspd:
| None, optional
| Reference spectrum for color coordinate to rfl mapping.
| None defaults to D65 (srgb has a D65 white point)
:D:
| None, optional
| Degree of (von Kries) adaptation from spd to refspd.
:cieobs:
| _CIEOBS, optional
| CMF set for calculation of xyz from spectral data.
:cspace:
| 'xyz', optional
| Color space for color coordinate to rfl mapping.
| Tip: Use linear space (e.g. 'xyz', 'Yuv',...) for (interp_type == 'nd'),
| and perceptually uniform space (e.g. 'ipt') for (interp_type == 'nearest')
:cspace_tf:
| {}, optional
| Dict with parameters for xyz_to_cspace and cspace_to_xyz transform.
:CSF:
| None, optional
| RGB camera response functions.
| If None: input :xyz: contains raw rgb values. Override :cspace:
| argument and perform estimation directly in raw rgb space!!!
:interp_type:
| 'nd', optional
| Options:
| - 'nd': perform n-dimensional linear interpolation using Delaunay triangulation.
| - 'nearest': perform nearest neighbour interpolation.
:k_neighbours:
| 4 or int, optional
| Number of nearest neighbours for reflectance spectrum interpolation.
| Neighbours are found using scipy.spatial.cKDTree
:show:
| True, optional
| Show images.
:verbosity:
| 0, optional
| If > 0: make a plot of the color coordinates of original and
rendered image pixels.
:show_ref_img:
| True, optional
| True: shows rendered image under reference spd. False: shows
| original image.
:write_to_file:
| None, optional
| None: do nothing, else: write to filename(+path) in :write_to_file:
:stack_test_ref:
| 12, optional
| - 12: left (test), right (ref) format for show and imwrite
| - 21: top (test), bottom (ref)
| - 1: only show/write test
| - 2: only show/write ref
| - 0: show both, write test
Returns:
:returns:
| img_hyp, img_ren,
| ndarrays with float hyperspectral image and rendered images
"""
# Get image:
#imread = lambda x: plt.imread(x) #matplotlib.pyplot
if img is not None:
if isinstance(img, str):
img = plt.imread(img) # use matplotlib.pyplot's imread
else:
img = plt.imread(_HYPSPCIM_DEFAULT_IMAGE)
if isinstance(img, np.uint8):
img = img / 255
elif isinstance(img, np.uint16):
img = img / (2**16 - 1)
# Convert to 2D format:
rgb = img.reshape(img.shape[0] * img.shape[1], 3) # *1.0: make float
rgb[rgb == 0] = _EPS # avoid division by zero for pure blacks.
# Get unique rgb values and positions:
rgb_u, rgb_indices = np.unique(rgb, return_inverse=True, axis=0)
# get rfl set:
if rfl is None: # use IESTM30['4880'] set
rfl = _CRI_RFL['ies-tm30']['4880']['5nm']
wlr = rfl[
0] # spectral reflectance set determines wavelength range for estimation (xyz_to_rfl())
# get Ref spd:
if refspd is None:
refspd = _CIE_ILLUMINANTS['D65'].copy()
refspd = cie_interp(
refspd, wlr,
kind='linear') # force spd to same wavelength range as rfl
# Convert rgb_u to xyz and lab-type values under assumed refspd:
if CSF is None:
xyz_wr = spd_to_xyz(refspd, cieobs=cieobs, relative=True)
xyz_ur = colortf(rgb_u * 255, tf='srgb>xyz')
else:
xyz_ur = rgb_u # for input in xyz_to_rfl (when CSF is not None: this functions assumes input is indeed rgb !!!)
# Estimate rfl's for xyz_ur:
rfl_est, xyzri = xyz_to_rfl(xyz_ur, rfl = rfl, out = 'rfl_est,xyz_est', \
refspd = refspd, D = D, cieobs = cieobs, \
cspace = cspace, cspace_tf = cspace_tf, CSF = CSF,\
interp_type = interp_type, k_neighbours = k_neighbours,
verbosity = verbosity)
# Get default test spd if none supplied:
if spd is None:
spd = _CIE_ILLUMINANTS['F4']
if CSF is None:
# calculate xyz values under test spd:
xyzti, xyztw = spd_to_xyz(spd, rfl=rfl_est, cieobs=cieobs, out=2)
# Chromatic adaptation from test spd to refspd:
if D is not None:
xyzti = cat.apply(xyzti, xyzw1=xyztw, xyzw2=xyz_wr, D=D)
# Convert xyzti under test spd to srgb:
rgbti = colortf(xyzti, tf='srgb') / 255
else:
# Calculate rgb coordinates from camera sensitivity functions under spd:
rgbti = rfl_to_rgb(rfl_est, spd=spd, CSF=CSF, wl=None)
# Chromatic adaptation from test spd to refspd:
if D is not None:
white = np.ones_like(spd)
white[0] = spd[0]
rgbwr = rfl_to_rgb(white, spd=refspd, CSF=CSF, wl=None)
rgbwt = rfl_to_rgb(white, spd=spd, CSF=CSF, wl=None)
rgbti = cat.apply_vonkries2(rgbti,
rgbwt,
rgbwr,
xyzw0=np.array([[1.0, 1.0, 1.0]]),
in_='rgb',
out_='rgb',
D=1)
# Reconstruct original locations for rendered image rgbs:
img_ren = rgbti[rgb_indices]
img_ren.shape = img.shape # reshape back to 3D size of original
img_ren = img_ren
# For output:
if show_ref_img == True:
rgb_ref = colortf(xyzri, tf='srgb') / 255 if (
CSF is None
) else xyzri # if CSF not None: xyzri contains rgbri !!!
img_ref = rgb_ref[rgb_indices]
img_ref.shape = img.shape # reshape back to 3D size of original
img_str = 'Rendered (under ref. spd)'
img = img_ref
else:
img_str = 'Original'
img = img
if (stack_test_ref > 0) | show == True:
if stack_test_ref == 21:
img_original_rendered = np.vstack(
(img_ren, np.ones((4, img.shape[1], 3)), img))
img_original_rendered_str = 'Rendered (under test spd)\n ' + img_str
elif stack_test_ref == 12:
img_original_rendered = np.hstack(
(img_ren, np.ones((img.shape[0], 4, 3)), img))
img_original_rendered_str = 'Rendered (under test spd) | ' + img_str
elif stack_test_ref == 1:
img_original_rendered = img_ren
img_original_rendered_str = 'Rendered (under test spd)'
elif stack_test_ref == 2:
img_original_rendered = img
img_original_rendered_str = img_str
elif stack_test_ref == 0:
img_original_rendered = img_ren
img_original_rendered_str = 'Rendered (under test spd)'
if write_to_file is not None:
# Convert from RGB to BGR formatand write:
#print('Writing rendering results to image file: {}'.format(write_to_file))
with warnings.catch_warnings():
warnings.simplefilter("ignore")
imsave(write_to_file, img_original_rendered)
if show == True:
# show images using pyplot.show():
plt.figure()
plt.imshow(img_original_rendered)
plt.title(img_original_rendered_str)
plt.gca().get_xaxis().set_ticklabels([])
plt.gca().get_yaxis().set_ticklabels([])
if stack_test_ref == 0:
plt.figure()
plt.imshow(img)
plt.title(img_str)
plt.axis('off')
if 'img_hyp' in out.split(','):
# Create hyper_spectral image:
rfl_image_2D = rfl_est[
rgb_indices +
1, :] # create array with all rfls required for each pixel
img_hyp = rfl_image_2D.reshape(img.shape[0], img.shape[1],
rfl_image_2D.shape[1])
# Setup output:
if out == 'img_hyp':
return img_hyp
elif out == 'img_ren':
return img_ren
else:
return eval(out)
_HYPSPCIM_PATH = _PKG_PATH + _SEP + 'hypspcim' + _SEP
_HYPSPCIM_DEFAULT_IMAGE = _PKG_PATH + _SEP + 'toolboxes' + _SEP + 'hypspcim' + _SEP + 'data' + _SEP + 'testimage1.jpg'
_ROUNDING = 6 # to speed up xyz_to_rfl search algorithm
# Nikon D700 camera sensitivity functions:
_CSF_NIKON_D700 = np.vstack(
(np.arange(400, 710, 10),
np.array([[
0.005, 0.007, 0.012, 0.015, 0.023, 0.025, 0.030, 0.026, 0.024, 0.019,
0.010, 0.004, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
0.000
],
[
0.000, 0.000, 0.000, 0.000, 0.000, 0.001, 0.002, 0.003,
0.005, 0.007, 0.012, 0.013, 0.015, 0.016, 0.017, 0.020,
0.013, 0.011, 0.009, 0.005, 0.001, 0.001, 0.001, 0.001,
0.001, 0.001, 0.001, 0.001, 0.002, 0.002, 0.003
],
[
0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
0.001, 0.003, 0.010, 0.012, 0.013, 0.022, 0.020, 0.020,
0.018, 0.017, 0.016, 0.016, 0.014, 0.014, 0.013
]])[::-1]))
def xyz_to_rfl(xyz, CSF = None, rfl = None, out = 'rfl_est', \
refspd = None, D = None, cieobs = _CIEOBS, \
cspace = 'xyz', cspace_tf = {},\
interp_type = 'nd', k_neighbours = 4, verbosity = 0):