def test_can_apply_intersection_mask_to_three_masked_arrays(self):
import numpy.ma as ma
array1 = ma.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], mask=[1, 1, 1, 0, 0, 0, 0, 0, 0, 0])
array2 = ma.array([2, 4, 5, 6, 7, 8, 4, 3, 6, 80], mask=[0, 1, 0, 0, 0, 0, 0, 1, 0, 0])
array3 = ma.array([2, 4, 5, 6, 7, 8, 4, 3, 6, 80], mask=[0, 0, 0, 0, 0, 0, 0, 0, 0, 1])
array1, array2 = apply_intersection_mask_to_two_arrays(array1, array2)
array1, array3 = apply_intersection_mask_to_two_arrays(array1, array3)
array1, array2 = apply_intersection_mask_to_two_arrays(array1, array2)
assert (ma.equal(array1.mask, [1, 1, 1, 0, 0, 0, 0, 1, 0, 1]).all())
assert (ma.equal(array2.mask, [1, 1, 1, 0, 0, 0, 0, 1, 0, 1]).all())
assert (ma.equal(array3.mask, [1, 1, 1, 0, 0, 0, 0, 1, 0, 1]).all())
def test_testUfuncs1(self):
# Test various functions such as sin, cos.
(x, y, a10, m1, m2, xm, ym, z, zm, xf, s) = self.d
assert_(eq(np.cos(x), cos(xm)))
assert_(eq(np.cosh(x), cosh(xm)))
assert_(eq(np.sin(x), sin(xm)))
assert_(eq(np.sinh(x), sinh(xm)))
assert_(eq(np.tan(x), tan(xm)))
assert_(eq(np.tanh(x), tanh(xm)))
with np.errstate(divide='ignore', invalid='ignore'):
assert_(eq(np.sqrt(abs(x)), sqrt(xm)))
assert_(eq(np.log(abs(x)), log(xm)))
assert_(eq(np.log10(abs(x)), log10(xm)))
assert_(eq(np.exp(x), exp(xm)))
assert_(eq(np.arcsin(z), arcsin(zm)))
assert_(eq(np.arccos(z), arccos(zm)))
assert_(eq(np.arctan(z), arctan(zm)))
assert_(eq(np.arctan2(x, y), arctan2(xm, ym)))
assert_(eq(np.absolute(x), absolute(xm)))
assert_(eq(np.equal(x, y), equal(xm, ym)))
assert_(eq(np.not_equal(x, y), not_equal(xm, ym)))
assert_(eq(np.less(x, y), less(xm, ym)))
assert_(eq(np.greater(x, y), greater(xm, ym)))
assert_(eq(np.less_equal(x, y), less_equal(xm, ym)))
assert_(eq(np.greater_equal(x, y), greater_equal(xm, ym)))
assert_(eq(np.conjugate(x), conjugate(xm)))
assert_(eq(np.concatenate((x, y)), concatenate((xm, ym))))
assert_(eq(np.concatenate((x, y)), concatenate((x, y))))
assert_(eq(np.concatenate((x, y)), concatenate((xm, y))))
assert_(eq(np.concatenate((x, y, x)), concatenate((x, ym, x))))
def test_testUfuncs1(self):
# Test various functions such as sin, cos.
(x, y, a10, m1, m2, xm, ym, z, zm, xf, s) = self.d
assert_(eq(np.cos(x), cos(xm)))
assert_(eq(np.cosh(x), cosh(xm)))
assert_(eq(np.sin(x), sin(xm)))
assert_(eq(np.sinh(x), sinh(xm)))
assert_(eq(np.tan(x), tan(xm)))
assert_(eq(np.tanh(x), tanh(xm)))
with np.errstate(divide='ignore', invalid='ignore'):
assert_(eq(np.sqrt(abs(x)), sqrt(xm)))
assert_(eq(np.log(abs(x)), log(xm)))
assert_(eq(np.log10(abs(x)), log10(xm)))
assert_(eq(np.exp(x), exp(xm)))
assert_(eq(np.arcsin(z), arcsin(zm)))
assert_(eq(np.arccos(z), arccos(zm)))
assert_(eq(np.arctan(z), arctan(zm)))
assert_(eq(np.arctan2(x, y), arctan2(xm, ym)))
assert_(eq(np.absolute(x), absolute(xm)))
assert_(eq(np.equal(x, y), equal(xm, ym)))
assert_(eq(np.not_equal(x, y), not_equal(xm, ym)))
assert_(eq(np.less(x, y), less(xm, ym)))
assert_(eq(np.greater(x, y), greater(xm, ym)))
assert_(eq(np.less_equal(x, y), less_equal(xm, ym)))
assert_(eq(np.greater_equal(x, y), greater_equal(xm, ym)))
assert_(eq(np.conjugate(x), conjugate(xm)))
assert_(eq(np.concatenate((x, y)), concatenate((xm, ym))))
assert_(eq(np.concatenate((x, y)), concatenate((x, y))))
assert_(eq(np.concatenate((x, y)), concatenate((xm, y))))
assert_(eq(np.concatenate((x, y, x)), concatenate((x, ym, x))))
def test_can_apply_intersection_mask_to_three_masked_arrays(self):
import numpy.ma as ma
array1 = ma.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
mask=[1, 1, 1, 0, 0, 0, 0, 0, 0, 0])
array2 = ma.array([2, 4, 5, 6, 7, 8, 4, 3, 6, 80],
mask=[0, 1, 0, 0, 0, 0, 0, 1, 0, 0])
array3 = ma.array([2, 4, 5, 6, 7, 8, 4, 3, 6, 80],
mask=[0, 0, 0, 0, 0, 0, 0, 0, 0, 1])
array1, array2 = apply_intersection_mask_to_two_arrays(array1, array2)
array1, array3 = apply_intersection_mask_to_two_arrays(array1, array3)
array1, array2 = apply_intersection_mask_to_two_arrays(array1, array2)
assert (ma.equal(array1.mask, [1, 1, 1, 0, 0, 0, 0, 1, 0, 1]).all())
assert (ma.equal(array2.mask, [1, 1, 1, 0, 0, 0, 0, 1, 0, 1]).all())
assert (ma.equal(array3.mask, [1, 1, 1, 0, 0, 0, 0, 1, 0, 1]).all())
def log_linear_vinterp(T,P,levs):
'''
# Author Charles Doutriaux
# Version 1.1
# Expect 2D field here so there''s no reorder which I suspect to do a memory leak
# email: [email protected]
# Converts a field from sigma levels to pressure levels
# Log linear interpolation
# Input
# T : temperature on sigma levels
# P : pressure field from TOP (level 0) to BOTTOM (last level)
# levs : pressure levels to interplate to (same units as P)
# Output
# t : temperature on pressure levels (levs)
# External: Numeric'''
import numpy.ma as MA
## from numpy.oldnumeric.ma import ones,Float,greater,less,logical_and,where,equal,log,asarray,Float16
sh=P.shape
nsigma=sh[0] # Number of sigma levels
try:
nlev=len(levs) # Number of pressure levels
except:
nlev=1 # if only one level len(levs) would breaks
t=[]
for ilv in range(nlev): # loop through pressure levels
try:
lev=levs[ilv] # get value for the level
except:
lev=levs # only 1 level passed
# print ' ......... level:',lev
Pabv=MA.ones(P[0].shape,Numeric.Float)
Tabv=-Pabv # Temperature on sigma level Above
Tbel=-Pabv # Temperature on sigma level Below
Pbel=-Pabv # Pressure on sigma level Below
Pabv=-Pabv # Pressure on sigma level Above
for isg in range(1,nsigma): # loop from second sigma level to last one
## print 'Sigma level #',isg
a = MA.greater(P[isg], lev) # Where is the pressure greater than lev
b = MA.less(P[isg-1],lev) # Where is the pressure less than lev
# Now looks if the pressure level is in between the 2 sigma levels
# If yes, sets Pabv, Pbel and Tabv, Tbel
Pabv=MA.where(MA.logical_and(a,b),P[isg],Pabv) # Pressure on sigma level Above
Tabv=MA.where(MA.logical_and(a,b),T[isg],Tabv) # Temperature on sigma level Above
Pbel=MA.where(MA.logical_and(a,b),P[isg-1],Pbel) # Pressure on sigma level Below
Tbel=MA.where(MA.logical_and(a,b),T[isg-1],Tbel) # Temperature on sigma level Below
# end of for isg in range(1,nsigma)
# val=where(equal(Pbel,-1.),Pbel.missing_value,lev) # set to missing value if no data below lev if there is
tl=MA.masked_where(MA.equal(Pbel,-1.),MA.log(lev/MA.absolute(Pbel))/MA.log(Pabv/Pbel)*(Tabv-Tbel)+Tbel) # Interpolation
t.append(tl) # add a level to the output
# end of for ilv in range(nlev)
return asMA(t).astype(Numeric.Float32) # convert t to an array
def GroupData(x, y):
"""
This function takes 2 variables, x (a grouping / dummy variable), and
y (the actual data). Returned are a list of vectors for each condition.
"""
uniques, freqs = UniqueVals(x)
data = []
for idx in zip(uniques, freqs):
indices = ma.equal(x, idx[0])
data.append(y[indices])
return data
def GroupData(x, y):
"""
This function takes 2 variables, x (a grouping / dummy variable), and
y (the actual data). Returned are a list of vectors for each condition.
"""
uniques, freqs = UniqueVals(x)
data = []
for idx in zip(uniques, freqs):
indices = ma.equal(x, idx[0])
data.append(y[indices])
return data
def corr_proba(r, ndata, ndataset=2, dof=False):
"""Probability of rejecting correlations
- **r**: Correlation coefficient
- **ndata**: Number of records use for correlations
- **ndataset**, optional: Number of datasets (1 for autocorrelations, else 2) [default: 2]
.. todo::
This must be rewritten using :mod:`scipy.stats`
"""
# TODO: use scipy for betai and _gamma?
from genutil.salstat import betai,_gammaln
# Basic tests
ndata = MA.masked_equal(ndata,0,copy=0)
r = MV2.masked_where(MA.equal(MA.absolute(r),1.),r,copy=0)
# Degree of freedom
if dof:
df = ndata
else:
df = ndata-2-ndataset
# Advanced test: prevent extreme values by locally decreasing the dof
reduc = N.ones(r.shape)
z = None
while z is None or MA.count(MA.masked_greater(z,-600.)):
if z is not None:
imax = MA.argmin(z.ravel())
reduc.flat[imax] += 1
dfr = df/reduc
t = r*MV2.sqrt(dfr/((1.0-r)* (1.0+r)))
a = 0.5*dfr
b = 0.5
x = df/(dfr+t**2)
z = _gammaln(a+b)-_gammaln(a)-_gammaln(b)+a*MA.log(x)+b*MA.log(1.0-x)
# Perfom the test and format the variable
prob = MV2.masked_array(betai(a,b,x),axes=r.getAxisList())*100
prob.id = 'corr_proba' ; prob.name = prob.id
prob.long_name = 'Probability of rejection'
prob.units = '%'
return prob
def corr_proba(r, ndata, ndataset=2, dof=False):
"""Probability of rejecting correlations
- **r**: Correlation coefficient
- **ndata**: Number of records use for correlations
- **ndataset**, optional: Number of datasets (1 for autocorrelations, else 2) [default: 2]
.. todo::
This must be rewritten using :mod:`scipy.stats`
"""
# Basic tests
ndata = MA.masked_equal(ndata,0,copy=0)
r = MV2.masked_where(MA.equal(MA.absolute(r),1.),r,copy=0)
# Degree of freedom
if dof:
df = ndata
else:
df = ndata-2-ndataset
# Advanced test: prevent extreme values by locally decreasing the dof
reduc = N.ones(r.shape)
z = None
while z is None or MA.count(MA.masked_greater(z,-600.)):
if z is not None:
imax = MA.argmin(z.ravel())
reduc.flat[imax] += 1
dfr = df/reduc
t = r*MV2.sqrt(dfr/((1.0-r)* (1.0+r)))
a = 0.5*dfr
b = 0.5
x = df/(dfr+t**2)
z = _gammaln(a+b)-_gammaln(a)-_gammaln(b)+a*MA.log(x)+b*MA.log(1.0-x)
# Perfom the test and format the variable
prob = MV2.masked_array(betai(a,b,x),axes=r.getAxisList())*100
prob.id = 'corr_proba' ; prob.name = prob.id
prob.long_name = 'Probability of rejection'
prob.units = '%'
return prob
def log_linear_vinterp(T, P, levs):
'''
# Author Charles Doutriaux
# Version 1.1
# Expect 2D field here so there''s no reorder which I suspect to do a memory leak
# email: [email protected]
# Converts a field from sigma levels to pressure levels
# Log linear interpolation
# Input
# T : temperature on sigma levels
# P : pressure field from TOP (level 0) to BOTTOM (last level)
# levs : pressure levels to interplate to (same units as P)
# Output
# t : temperature on pressure levels (levs)
# External: Numeric'''
import numpy.ma as MA
## from numpy.oldnumeric.ma import ones,Float,greater,less,logical_and,where,equal,log,asarray,Float16
sh = P.shape
nsigma = sh[0] # Number of sigma levels
try:
nlev = len(levs) # Number of pressure levels
except:
nlev = 1 # if only one level len(levs) would breaks
t = []
for ilv in range(nlev): # loop through pressure levels
try:
lev = levs[ilv] # get value for the level
except:
lev = levs # only 1 level passed
# print ' ......... level:',lev
Pabv = MA.ones(P[0].shape, Numeric.Float)
Tabv = -Pabv # Temperature on sigma level Above
Tbel = -Pabv # Temperature on sigma level Below
Pbel = -Pabv # Pressure on sigma level Below
Pabv = -Pabv # Pressure on sigma level Above
for isg in range(1,
nsigma): # loop from second sigma level to last one
## print 'Sigma level #',isg
a = MA.greater(P[isg],
lev) # Where is the pressure greater than lev
b = MA.less(P[isg - 1], lev) # Where is the pressure less than lev
# Now looks if the pressure level is in between the 2 sigma levels
# If yes, sets Pabv, Pbel and Tabv, Tbel
Pabv = MA.where(MA.logical_and(a, b), P[isg],
Pabv) # Pressure on sigma level Above
Tabv = MA.where(MA.logical_and(a, b), T[isg],
Tabv) # Temperature on sigma level Above
Pbel = MA.where(MA.logical_and(a, b), P[isg - 1],
Pbel) # Pressure on sigma level Below
Tbel = MA.where(MA.logical_and(a, b), T[isg - 1],
Tbel) # Temperature on sigma level Below
# end of for isg in range(1,nsigma)
# val=where(equal(Pbel,-1.),Pbel.missing_value,lev) # set to missing value if no data below lev if there is
tl = MA.masked_where(
MA.equal(Pbel, -1.),
MA.log(lev / MA.absolute(Pbel)) / MA.log(Pabv / Pbel) *
(Tabv - Tbel) + Tbel) # Interpolation
t.append(tl) # add a level to the output
# end of for ilv in range(nlev)
return asMA(t).astype(Numeric.Float32) # convert t to an array
def test_testOddFeatures(self):
# Test of other odd features
x = arange(20)
x = x.reshape(4, 5)
x.flat[5] = 12
assert_(x[1, 0] == 12)
z = x + 10j * x
assert_(eq(z.real, x))
assert_(eq(z.imag, 10 * x))
assert_(eq((z * conjugate(z)).real, 101 * x * x))
z.imag[...] = 0.0
x = arange(10)
x[3] = masked
assert_(str(x[3]) == str(masked))
c = x >= 8
assert_(count(where(c, masked, masked)) == 0)
assert_(shape(where(c, masked, masked)) == c.shape)
z = where(c, x, masked)
assert_(z.dtype is x.dtype)
assert_(z[3] is masked)
assert_(z[4] is masked)
assert_(z[7] is masked)
assert_(z[8] is not masked)
assert_(z[9] is not masked)
assert_(eq(x, z))
z = where(c, masked, x)
assert_(z.dtype is x.dtype)
assert_(z[3] is masked)
assert_(z[4] is not masked)
assert_(z[7] is not masked)
assert_(z[8] is masked)
assert_(z[9] is masked)
z = masked_where(c, x)
assert_(z.dtype is x.dtype)
assert_(z[3] is masked)
assert_(z[4] is not masked)
assert_(z[7] is not masked)
assert_(z[8] is masked)
assert_(z[9] is masked)
assert_(eq(x, z))
x = array([1., 2., 3., 4., 5.])
c = array([1, 1, 1, 0, 0])
x[2] = masked
z = where(c, x, -x)
assert_(eq(z, [1., 2., 0., -4., -5]))
c[0] = masked
z = where(c, x, -x)
assert_(eq(z, [1., 2., 0., -4., -5]))
assert_(z[0] is masked)
assert_(z[1] is not masked)
assert_(z[2] is masked)
assert_(eq(masked_where(greater(x, 2), x), masked_greater(x, 2)))
assert_(eq(masked_where(greater_equal(x, 2), x),
masked_greater_equal(x, 2)))
assert_(eq(masked_where(less(x, 2), x), masked_less(x, 2)))
assert_(eq(masked_where(less_equal(x, 2), x), masked_less_equal(x, 2)))
assert_(eq(masked_where(not_equal(x, 2), x), masked_not_equal(x, 2)))
assert_(eq(masked_where(equal(x, 2), x), masked_equal(x, 2)))
assert_(eq(masked_where(not_equal(x, 2), x), masked_not_equal(x, 2)))
assert_(eq(masked_inside(list(range(5)), 1, 3), [0, 199, 199, 199, 4]))
assert_(eq(masked_outside(list(range(5)), 1, 3), [199, 1, 2, 3, 199]))
assert_(eq(masked_inside(array(list(range(5)),
mask=[1, 0, 0, 0, 0]), 1, 3).mask,
[1, 1, 1, 1, 0]))
assert_(eq(masked_outside(array(list(range(5)),
mask=[0, 1, 0, 0, 0]), 1, 3).mask,
[1, 1, 0, 0, 1]))
assert_(eq(masked_equal(array(list(range(5)),
mask=[1, 0, 0, 0, 0]), 2).mask,
[1, 0, 1, 0, 0]))
assert_(eq(masked_not_equal(array([2, 2, 1, 2, 1],
mask=[1, 0, 0, 0, 0]), 2).mask,
[1, 0, 1, 0, 1]))
assert_(eq(masked_where([1, 1, 0, 0, 0], [1, 2, 3, 4, 5]),
[99, 99, 3, 4, 5]))
atest = ones((10, 10, 10), dtype=np.float32)
btest = zeros(atest.shape, MaskType)
ctest = masked_where(btest, atest)
assert_(eq(atest, ctest))
z = choose(c, (-x, x))
assert_(eq(z, [1., 2., 0., -4., -5]))
assert_(z[0] is masked)
assert_(z[1] is not masked)
assert_(z[2] is masked)
x = arange(6)
x[5] = masked
y = arange(6) * 10
y[2] = masked
c = array([1, 1, 1, 0, 0, 0], mask=[1, 0, 0, 0, 0, 0])
cm = c.filled(1)
z = where(c, x, y)
zm = where(cm, x, y)
assert_(eq(z, zm))
assert_(getmask(zm) is nomask)
assert_(eq(zm, [0, 1, 2, 30, 40, 50]))
z = where(c, masked, 1)
assert_(eq(z, [99, 99, 99, 1, 1, 1]))
z = where(c, 1, masked)
assert_(eq(z, [99, 1, 1, 99, 99, 99]))
def test_testOddFeatures(self):
# Test of other odd features
x = arange(20)
x = x.reshape(4, 5)
x.flat[5] = 12
assert_(x[1, 0] == 12)
z = x + 10j * x
assert_(eq(z.real, x))
assert_(eq(z.imag, 10 * x))
assert_(eq((z * conjugate(z)).real, 101 * x * x))
z.imag[...] = 0.0
x = arange(10)
x[3] = masked
assert_(str(x[3]) == str(masked))
c = x >= 8
assert_(count(where(c, masked, masked)) == 0)
assert_(shape(where(c, masked, masked)) == c.shape)
z = where(c, x, masked)
assert_(z.dtype is x.dtype)
assert_(z[3] is masked)
assert_(z[4] is masked)
assert_(z[7] is masked)
assert_(z[8] is not masked)
assert_(z[9] is not masked)
assert_(eq(x, z))
z = where(c, masked, x)
assert_(z.dtype is x.dtype)
assert_(z[3] is masked)
assert_(z[4] is not masked)
assert_(z[7] is not masked)
assert_(z[8] is masked)
assert_(z[9] is masked)
z = masked_where(c, x)
assert_(z.dtype is x.dtype)
assert_(z[3] is masked)
assert_(z[4] is not masked)
assert_(z[7] is not masked)
assert_(z[8] is masked)
assert_(z[9] is masked)
assert_(eq(x, z))
x = array([1., 2., 3., 4., 5.])
c = array([1, 1, 1, 0, 0])
x[2] = masked
z = where(c, x, -x)
assert_(eq(z, [1., 2., 0., -4., -5]))
c[0] = masked
z = where(c, x, -x)
assert_(eq(z, [1., 2., 0., -4., -5]))
assert_(z[0] is masked)
assert_(z[1] is not masked)
assert_(z[2] is masked)
assert_(eq(masked_where(greater(x, 2), x), masked_greater(x, 2)))
assert_(eq(masked_where(greater_equal(x, 2), x),
masked_greater_equal(x, 2)))
assert_(eq(masked_where(less(x, 2), x), masked_less(x, 2)))
assert_(eq(masked_where(less_equal(x, 2), x), masked_less_equal(x, 2)))
assert_(eq(masked_where(not_equal(x, 2), x), masked_not_equal(x, 2)))
assert_(eq(masked_where(equal(x, 2), x), masked_equal(x, 2)))
assert_(eq(masked_where(not_equal(x, 2), x), masked_not_equal(x, 2)))
assert_(eq(masked_inside(list(range(5)), 1, 3), [0, 199, 199, 199, 4]))
assert_(eq(masked_outside(list(range(5)), 1, 3), [199, 1, 2, 3, 199]))
assert_(eq(masked_inside(array(list(range(5)),
mask=[1, 0, 0, 0, 0]), 1, 3).mask,
[1, 1, 1, 1, 0]))
assert_(eq(masked_outside(array(list(range(5)),
mask=[0, 1, 0, 0, 0]), 1, 3).mask,
[1, 1, 0, 0, 1]))
assert_(eq(masked_equal(array(list(range(5)),
mask=[1, 0, 0, 0, 0]), 2).mask,
[1, 0, 1, 0, 0]))
assert_(eq(masked_not_equal(array([2, 2, 1, 2, 1],
mask=[1, 0, 0, 0, 0]), 2).mask,
[1, 0, 1, 0, 1]))
assert_(eq(masked_where([1, 1, 0, 0, 0], [1, 2, 3, 4, 5]),
[99, 99, 3, 4, 5]))
atest = ones((10, 10, 10), dtype=np.float32)
btest = zeros(atest.shape, MaskType)
ctest = masked_where(btest, atest)
assert_(eq(atest, ctest))
z = choose(c, (-x, x))
assert_(eq(z, [1., 2., 0., -4., -5]))
assert_(z[0] is masked)
assert_(z[1] is not masked)
assert_(z[2] is masked)
x = arange(6)
x[5] = masked
y = arange(6) * 10
y[2] = masked
c = array([1, 1, 1, 0, 0, 0], mask=[1, 0, 0, 0, 0, 0])
cm = c.filled(1)
z = where(c, x, y)
zm = where(cm, x, y)
assert_(eq(z, zm))
assert_(getmask(zm) is nomask)
assert_(eq(zm, [0, 1, 2, 30, 40, 50]))
z = where(c, masked, 1)
assert_(eq(z, [99, 99, 99, 1, 1, 1]))
z = where(c, 1, masked)
assert_(eq(z, [99, 1, 1, 99, 99, 99]))
def compute_photometric_stereo_impl(lights, images):
"""
Given a set of images taken from the same viewpoint and a corresponding set
of directions for light sources, this function computes the albedo and
normal map of a Lambertian scene.
If the computed albedo for a pixel has an L2 norm less than 1e-7, then set
the albedo to black and set the normal to the 0 vector.
Normals should be unit vectors.
Input:
lights -- 3 x N array. Columns are normalized and are to be
interpreted as lighting directions.
images -- list of N images. Each image is of the same scene from the
same viewpoint, but under the lighting condition specified in
lights. Images are height x width x channels arrays, all
with identical dimensions.
Output:
albedo -- float32 height x width x channels image with dimensions
matching the input images.
normals -- float32 height x width x 3 image with dimensions matching
the input images.
"""
# Calculate dimensions for inputs & outputs.
(height, width, channel) = images[0].shape
N = len(images)
# Initialize arrays for albedo & normals; dtype='float32'.
albedo = np.zeros((height,width,channel),dtype='float32')
normals = np.zeros((height,width,3),dtype='float32')
# Accumulator to hold G of each RGB color channel.
G = np.zeros((height*width,3,channel),dtype='float32')
for ch in xrange(channel):
# Stack images in a (pixel x num_images) array.
I = np.zeros((height*width, N),dtype='float32')
for img_idx in xrange(N):
I[:,img_idx] = images[img_idx][:,:,ch].reshape(height*width,)
# Store G_RGB in G_Accumulator.
G[:,:,ch] = I.dot(lights.T).dot(np.linalg.inv(lights.dot(lights.T)))
# Calculate the albedo.
G_norm = np.linalg.norm(G,axis=1)
G_norm = G_norm[:,np.newaxis]
G_norm[G_norm < 1.0e-7] = 0.0
albedo = G_norm.reshape(height,width,channel)
# Calculate G_grey matrix.
G_grey = (np.sum(G, axis=2)/3.0)
# Calculate ||G_grey||; set entries less than 1e-7 to 0.
G_grey_norm = np.linalg.norm(G_grey, axis=1).astype(dtype='float32')
G_grey_norm = G_grey_norm[:,np.newaxis]
G_grey_norm[G_grey_norm < 1e-7] = 0.0
# Mask for ||G_grey||; True for index containing 0-values.
mask = ma.equal(G_grey_norm, 0.0)
# Replace 0-values with 1.0 temporarily in ||G_grey||.
G_grey_norm[mask] = 1.0
# Calculate normals.
N_matrix = (G_grey/G_grey_norm)
N_matrix[mask] = 0.0
normals = N_matrix.reshape(height,width,3)
return albedo, normals
