def iFSHT(coeffs,
envmap_size,
envmap_format='latlong',
reduction_type='right'):
if reduction_type != 'right':
raise NotImplemented()
degrees = int(np.sqrt(8 * coeffs.shape[0]) / 2. - 1)
ch = coeffs.shape[1]
envmap = EnvironmentMap(np.zeros((envmap_size, envmap_size * 2, ch)),
envmap_format)
envmap.data = envmap.data.astype(np.complex128)
P, _ = _getP(envmap, degrees)
i = 0
for l in tqdm(range(degrees + 1)):
for m in range(0, l + 1):
for c in range(ch):
envmap.data[:, m, c] += P[:, i] * coeffs[i, c]
i += 1
#import pdb; pdb.set_trace()
envmap.data = np.fft.ifft(envmap.data, axis=1).real
return envmap
def inverseSphericalHarmonicTransform(coeffs,
envmap_height=512,
format_='latlong',
reduction_type='right'):
"""
Recovers an EnvironmentMap from a list of coefficients.
"""
degrees = np.asscalar(np.sqrt(coeffs.shape[0]).astype('int')) - 1
coeffs = addRedundantCoeffs(coeffs, reduction_type)[..., np.newaxis]
ch = coeffs.shape[1] if len(coeffs.shape) > 0 else 1
retval = EnvironmentMap(envmap_height, format_)
retval.data = np.zeros((retval.data.shape[0], retval.data.shape[1], ch),
dtype=np.float32)
x, y, z, valid = retval.worldCoordinates()
theta = np.arctan2(x, -z)
phi = np.arccos(y)
for l in range(degrees + 1):
for col, m in enumerate(range(-l, l + 1)):
Y = sph_harm(m, l, theta, phi)
for c in range(ch):
retval.data[..., c] += (coeffs[l**2 + col, c] * Y).real
return retval
def __call__(self, sample):
from envmap import EnvironmentMap
image = EnvironmentMap(64, 'LatLong')
image.data = sample
rotation = self.random_direction()
img_hdr = image.rotate('DCM', rotation).data.astype('float32')
sample = img_hdr
return sample