def shearlet_inpainting(self, masked_img, mask):
"""
Inpaint a patch using iterative thresholding and pyshearlab
:param masked_img: image that has been masked : void regions set to 0
:type masked_img: numpy array
:param mask: mask that is 0 in void regions and 1 otherwise
:type mask: numpy array
:return: tuple of inpainted image patch and patch coordinates
"""
normalized_coeffs = psl.SLnormalizeCoefficients2D(
psl.SLsheardec2D(masked_img, self.shearlet_system),
self.shearlet_system)
delta = np.max(np.abs(normalized_coeffs))
decay = self.stop_factor**(1 / (max(1, self.iterations - 1)))
inpainted_img = np.zeros(masked_img.shape)
for i in range(self.iterations):
res = mask * (masked_img - inpainted_img)
coeffs = psl.SLsheardec2D(inpainted_img + res,
self.shearlet_system)
coeffs = coeffs * (np.abs(
psl.SLnormalizeCoefficients2D(coeffs, self.shearlet_system)) >
delta)
inpainted_img = psl.SLshearrec2D(coeffs, self.shearlet_system)
delta = delta * decay
return inpainted_img
def shearlets(matrix):
# hyperparameter settings (including level at which to threshold)
sigma = 30
scales = 2
thresholdingFactor = shearletThresholdFactor
# Converting 2D matrix into flaot
matrix = matrix.astype(float)
X = matrix
## create shearlets system
shearletSystem = pyshearlab.SLgetShearletSystem2D(0, X.shape[0],
X.shape[1], scales)
# decomposition, produces shearlet coefficients
coeffs = pyshearlab.SLsheardec2D(X, shearletSystem)
# calculating Root Mean Square value of each coeficient vector that is assosiated with a pixel
# i.e for sherlet system made out of scales = 2, produces coeficient vector of length 17 for each pixel
# RMS value is worked out on each of these vectors and the multiplied by the vector
# A 1xnShearlets array containing the root mean squares (L2-norm divided by
# sqrt(X*Y)) of all shearlets stored in shearletSystem["shearlets"]. These values can be used to normalize
# shearlet coefficients to make them comparable.
oldCoeffs = coeffs.copy()
weights = np.ones(coeffs.shape)
for j in range(len(shearletSystem["RMS"])):
weights[:, :, j] = shearletSystem["RMS"][j] * np.ones(
(X.shape[0], X.shape[1]))
# Thresholding the coefficients based on the setting in the hyperparameters and RMS weights
# Setting coefficients to 0 for value that do not pass the threshold
coeffs = np.real(coeffs)
zero_indices = np.abs(coeffs) / (thresholdingFactor * weights * sigma) < 1
coeffs[zero_indices] = 0
# reconstruction of the signal thresholded coefficients, returning the reconsturcted signal
Xrec = pyshearlab.SLshearrec2D(coeffs, shearletSystem)
return Xrec
def shearlet_frame_thresh(frame, fraction_coeff):
n, _ = frame.shape
frame_wt = pyshearlab.SLsheardec2D(frame, shearletSystem)
sorted_wt = np.sort(np.ravel(abs(frame_wt)))[::-1]
n_pix, = sorted_wt.shape
treshold_value = sorted_wt[int(n_pix * fraction_coeff)]
frame_wt_T = np.multiply(frame_wt, (abs(frame_wt) > treshold_value))
frame_T = pyshearlab.SLshearrec2D(frame_wt_T, shearletSystem)
return frame_T
def test_inverse(dtype, shearletSystem):
"""Validate the inverse."""
X = np.random.randn(*shearletSystem['size']).astype(dtype)
# decomposition
coeffs = pyshearlab.SLsheardec2D(X, shearletSystem)
# reconstruction
Xrec = pyshearlab.SLshearrec2D(coeffs, shearletSystem)
assert Xrec.dtype == X.dtype
assert Xrec.shape == X.shape
assert np.linalg.norm(X - Xrec) < 1e-5 * np.linalg.norm(X)
def test_adjoint_of_inverse(dtype, shearletSystem):
"""Validate the adjoint of the inverse."""
X = np.random.randn(*shearletSystem['size']).astype(dtype)
# decomposition
coeffs = pyshearlab.SLsheardec2D(X, shearletSystem)
# reconstruction
Xrec = pyshearlab.SLshearrec2D(coeffs, shearletSystem)
Xrecadj = pyshearlab.SLshearrecadjoint2D(Xrec, shearletSystem)
assert Xrecadj.dtype == X.dtype
assert Xrecadj.shape == coeffs.shape
# <A^-1x, A^-1x> = <A^-* A^-1 x, x>.
assert (pytest.approx(np.vdot(Xrec, Xrec), rel=1e-3, abs=0) ==
np.vdot(Xrecadj, coeffs))
toc()
tic()
print("decomposition, thresholding and reconstruction...")
# decomposition
coeffs = pyshearlab.SLsheardec2D(Xnoisy, shearletSystem)
# thresholding
oldCoeffs = coeffs.copy()
weights = np.ones(coeffs.shape)
for j in range(len(shearletSystem["RMS"])):
weights[:, :, j] = shearletSystem["RMS"][j] * np.ones(
(X.shape[0], X.shape[1]))
coeffs = np.real(coeffs)
j = np.abs(coeffs) / (thresholdingFactor * weights * sigma) < 1
coeffs[j] = 0
# reconstruction
Xrec = pyshearlab.SLshearrec2D(coeffs, shearletSystem)
toc()
PSNR = pyshearlab.SLcomputePSNR(X, Xrec)
print("PSNR: " + str(PSNR))
#sio.savemat("PyShearLab_DenoisingExample.mat", {"weights": weights, "XPyNoisy": Xnoisy,
# "XPyDenoised": Xrec, "PyPSNR": PSNR, "coeffThrPy": coeffs, "oldCoeffs": oldCoeffs})
plt.gray()
plt.imshow(Xrec)
plt.colorbar()
plt.show()
def _call(self, x):
"""Return ``self(x)``."""
with self.op.mutex:
x = np.moveaxis(x, 0, -1)
return pyshearlab.SLshearrec2D(x, self.op.shearlet_system)