Remove old implementation if TV filter

This commit is contained in:
Johannes Schönberger
2012-11-02 20:18:28 +01:00
parent cda03cfba4
commit dd34097fe4
3 changed files with 4 additions and 247 deletions
+1 -2
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@@ -3,7 +3,6 @@ from .ctmf import median_filter
from ._canny import canny
from .edges import (sobel, hsobel, vsobel, scharr, hscharr, vscharr, prewitt,
hprewitt, vprewitt)
from .denoise import tv_denoise
from ._denoise import denoise_bilateral, denoise_tv
from ._denoise import denoise_bilateral, denoise_tv, tv_denoise
from ._rank_order import rank_order
from .thresholding import threshold_otsu, threshold_adaptive
+3
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@@ -10,6 +10,7 @@ from libc.stdlib cimport malloc, free
from libc.float cimport DBL_MAX
from skimage._shared.interpolation cimport get_pixel3d
from skimage.util import img_as_float
from skimage._shared.utils import deprecated
cdef inline double _gaussian_weight(double sigma, double value):
@@ -342,3 +343,5 @@ def denoise_tv(image, double weight, int max_iter=100, double eps=1e-3):
i += 1
return np.squeeze(u[1:-1, 1:-1])
tv_denoise = deprecated('skimage.filter.denoise_tv')(denoise_tv)
-245
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@@ -1,245 +0,0 @@
import numpy as np
from skimage import img_as_float
from skimage._shared.utils import deprecated
def _denoise_tv_3d(im, weight=100, eps=2.e-4, n_iter_max=200):
"""Perform total-variation denoising on 3-D arrays.
Parameters
----------
im: ndarray
3-D input data to be denoised.
weight: float, optional
Denoising weight. The greater ``weight``, the more denoising (at
the expense of fidelity to ``input``).
eps: float, optional
Relative difference of the value of the cost function that determines
the stop criterion. The algorithm stops when:
(E_(n-1) - E_n) < eps * E_0
n_iter_max: int, optional
Maximal number of iterations used for the optimization.
Returns
-------
out: ndarray
Denoised array of floats.
Notes
-----
Rudin, Osher and Fatemi algorithm.
Examples
---------
First build synthetic noisy data
>>> x, y, z = np.ogrid[0:40, 0:40, 0:40]
>>> mask = (x -22)**2 + (y - 20)**2 + (z - 17)**2 < 8**2
>>> mask = mask.astype(np.float)
>>> mask += 0.2*np.random.randn(*mask.shape)
>>> res = denoise_tv_3d(mask, weight=100)
"""
px = np.zeros_like(im)
py = np.zeros_like(im)
pz = np.zeros_like(im)
gx = np.zeros_like(im)
gy = np.zeros_like(im)
gz = np.zeros_like(im)
d = np.zeros_like(im)
i = 0
while i < n_iter_max:
d = - px - py - pz
d[1:] += px[:-1]
d[:, 1:] += py[:, :-1]
d[:, :, 1:] += pz[:, :, :-1]
out = im + d
E = (d**2).sum()
gx[:-1] = np.diff(out, axis=0)
gy[:, :-1] = np.diff(out, axis=1)
gz[:, :, :-1] = np.diff(out, axis=2)
norm = np.sqrt(gx**2 + gy**2 + gz**2)
E += weight * norm.sum()
norm *= 0.5 / weight
norm += 1.
px -= 1. / 6. * gx
px /= norm
py -= 1. / 6. * gy
py /= norm
pz -= 1 / 6. * gz
pz /= norm
E /= float(im.size)
if i == 0:
E_init = E
E_previous = E
else:
if np.abs(E_previous - E) < eps * E_init:
break
else:
E_previous = E
i += 1
return out
def _denoise_tv_2d(im, weight=50, eps=2.e-4, n_iter_max=200):
"""Perform total-variation denoising.
Parameters
----------
im: ndarray
Input data to be denoised.
weight: float, optional
Denoising weight. The greater ``weight``, the more denoising (at
the expense of fidelity to ``input``)
eps: float, optional
Relative difference of the value of the cost function that determines
the stop criterion. The algorithm stops when:
(E_(n-1) - E_n) < eps * E_0
n_iter_max: int, optional
Maximal number of iterations used for the optimization.
Returns
-------
out: ndarray
Denoised array of floats.
Notes
-----
The principle of total variation denoising is explained in
http://en.wikipedia.org/wiki/Total_variation_denoising.
This code is an implementation of the algorithm of Rudin, Fatemi and Osher
that was proposed by Chambolle in [1]_.
References
----------
.. [1] A. Chambolle, An algorithm for total variation minimization and
applications, Journal of Mathematical Imaging and Vision,
Springer, 2004, 20, 89-97.
Examples
---------
>>> import scipy
>>> lena = scipy.lena()
>>> import scipy
>>> lena = scipy.lena().astype(np.float)
>>> lena += 0.5 * lena.std()*np.random.randn(*lena.shape)
>>> denoised_lena = denoise_tv(lena, weight=60.0)
"""
px = np.zeros_like(im)
py = np.zeros_like(im)
gx = np.zeros_like(im)
gy = np.zeros_like(im)
d = np.zeros_like(im)
i = 0
while i < n_iter_max:
d = -px - py
d[1:] += px[:-1]
d[:, 1:] += py[:, :-1]
out = im + d
E = (d**2).sum()
gx[:-1] = np.diff(out, axis=0)
gy[:, :-1] = np.diff(out, axis=1)
norm = np.sqrt(gx**2 + gy**2)
E += weight * norm.sum()
norm *= 0.5 / weight
norm += 1
px -= 0.25 * gx
px /= norm
py -= 0.25 * gy
py /= norm
E /= float(im.size)
if i == 0:
E_init = E
E_previous = E
else:
if np.abs(E_previous - E) < eps * E_init:
break
else:
E_previous = E
i += 1
return out
def denoise_tv(im, weight=50, eps=2.e-4, n_iter_max=200):
"""Perform total-variation denoising on 2-d and 3-d images.
Parameters
----------
im: ndarray (2d or 3d) of ints, uints or floats
Input data to be denoised. `im` can be of any numeric type,
but it is cast into an ndarray of floats for the computation
of the denoised image.
weight: float, optional
Denoising weight. The greater ``weight``, the more denoising (at
the expense of fidelity to ``input``).
eps: float, optional
Relative difference of the value of the cost function that
determines the stop criterion. The algorithm stops when:
(E_(n-1) - E_n) < eps * E_0
n_iter_max: int, optional
Maximal number of iterations used for the optimization.
Returns
-------
out: ndarray
Denoised array of floats.
Notes
-----
The principle of total variation denoising is explained in
http://en.wikipedia.org/wiki/Total_variation_denoising
The principle of total variation denoising is to minimize the
total variation of the image, which can be roughly described as
the integral of the norm of the image gradient. Total variation
denoising tends to produce "cartoon-like" images, that is,
piecewise-constant images.
This code is an implementation of the algorithm of Rudin, Fatemi and Osher
that was proposed by Chambolle in [1]_.
References
----------
.. [1] A. Chambolle, An algorithm for total variation minimization and
applications, Journal of Mathematical Imaging and Vision,
Springer, 2004, 20, 89-97.
Examples
---------
>>> import scipy
>>> # 2D example using lena
>>> lena = scipy.lena()
>>> import scipy
>>> lena = scipy.lena().astype(np.float)
>>> lena += 0.5 * lena.std()*np.random.randn(*lena.shape)
>>> denoised_lena = denoise_tv(lena, weight=60)
>>> # 3D example on synthetic data
>>> x, y, z = np.ogrid[0:40, 0:40, 0:40]
>>> mask = (x -22)**2 + (y - 20)**2 + (z - 17)**2 < 8**2
>>> mask = mask.astype(np.float)
>>> mask += 0.2*np.random.randn(*mask.shape)
>>> res = denoise_tv_3d(mask, weight=100)
"""
im_type = im.dtype
if not im_type.kind == 'f':
im = img_as_float(im)
if im.ndim == 2:
out = _denoise_tv_2d(im, weight, eps, n_iter_max)
elif im.ndim == 3:
out = _denoise_tv_3d(im, weight, eps, n_iter_max)
else:
raise ValueError('only 2-d and 3-d images may be denoised with this '
'function')
return out
tv_denoise = deprecated('skimage.filter.denoise_tv')(denoise_tv)