def main():
usage = '''
Usage:
------------------------------------------------
RX anomaly detection for multi- and hyperspectral images
python %s [OPTIONS] filename
Options:
-h this help
-------------------------------------------------''' % sys.argv[0]
options, args = getopt.getopt(sys.argv[1:], 'h')
for option, value in options:
if option == '-h':
print usage
return
gdal.AllRegister()
infile = args[0]
path = os.path.dirname(infile)
basename = os.path.basename(infile)
root, ext = os.path.splitext(basename)
outfile = path + '/' + root + '_rx' + ext
print '------------ RX ---------------'
print time.asctime()
print 'Input %s' % infile
start = time.time()
# input image, convert to ENVI format
inDataset = gdal.Open(infile, GA_ReadOnly)
cols = inDataset.RasterXSize
rows = inDataset.RasterYSize
projection = inDataset.GetProjection()
geotransform = inDataset.GetGeoTransform()
driver = gdal.GetDriverByName('ENVI')
enviDataset = driver.CreateCopy('imagery/entmp', inDataset)
inDataset = None
enviDataset = None
# RX-algorithm
img = envi.open('imagery/entmp.hdr')
arr = img.load()
rx = RX(background=calc_stats(arr))
res = rx(arr)
# output
driver = gdal.GetDriverByName('GTiff')
outDataset = driver.Create(outfile,cols,rows,1,\
GDT_Float32)
if geotransform is not None:
outDataset.SetGeoTransform(geotransform)
if projection is not None:
outDataset.SetProjection(projection)
outBand = outDataset.GetRasterBand(1)
outBand.WriteArray(np.asarray(res, np.float32), 0, 0)
outBand.FlushCache()
outDataset = None
os.remove('imagery/entmp')
os.remove('imagery/entmp.hdr')
print 'Result written to %s' % outfile
print 'elapsed time: %s' % str(time.time() - start)
def __call__(self, X):
'''Compute ACE detector scores for X.
Arguments:
`X` (numpy.ndarray):
For an image with shape (R, C, B), `X` can be a vector of
length B (single pixel) or an ndarray of shape (R, C, B) or
(R * C, B).
Returns numpy.ndarray or float:
The return value will be the RX detector score (squared Mahalanobis
distance) for each pixel given. If `X` is a single pixel, a float
will be returned; otherwise, the return value will be an ndarray
of floats with one less dimension than the input.
'''
from spectral.algorithms.algorithms import calc_stats
if not isinstance(X, np.ndarray):
raise TypeError('Expected a numpy.ndarray.')
shape = X.shape
if X.ndim == 1:
# Compute ACE score for single pixel
if self._background.mean is not None:
X = X - self._background.mean
z = self._background.sqrt_inv_cov.dot(X)
return z.dot(self._P).dot(z) / (z.dot(z))
if self._background is None:
self.set_background(calc_stats(X))
if self.vectorize:
# Compute all scores at once
if self._background.mean is not None:
X = X - self._background.mean
if X.ndim == 3:
X = X.reshape((-1, X.shape[-1]))
z = self._background.sqrt_inv_cov.dot(X.T).T
zP = np.dot(z, self._P)
zPz = np.einsum('ij,ij->i', zP, z)
zz = np.einsum('ij,ij->i', z, z)
return (zPz / zz).reshape(shape[:-1])
else:
# Call recursively for each pixel
return np.apply_along_axis(self, -1, X)
def __call__(self, X):
'''Compute ACE detector scores for X.
Arguments:
`X` (numpy.ndarray):
For an image with shape (R, C, B), `X` can be a vector of
length B (single pixel) or an ndarray of shape (R, C, B) or
(R * C, B).
Returns numpy.ndarray or float:
The return value will be the RX detector score (squared Mahalanobis
distance) for each pixel given. If `X` is a single pixel, a float
will be returned; otherwise, the return value will be an ndarray
of floats with one less dimension than the input.
'''
from spectral.algorithms.algorithms import calc_stats
if not isinstance(X, np.ndarray):
raise TypeError('Expected a numpy.ndarray.')
shape = X.shape
if X.ndim == 1:
# Compute ACE score for single pixel
if self._background.mean is not None:
X = X - self._background.mean
z = self._background.sqrt_inv_cov.dot(X)
return z.dot(self._P).dot(z) / (z.dot(z))
if self._background is None:
self.set_background(calc_stats(X))
if self.vectorize:
# Compute all scores at once
if self._background.mean is not None:
X = X - self._background.mean
if X.ndim == 3:
X = X.reshape((-1, X.shape[-1]))
z = self._background.sqrt_inv_cov.dot(X.T).T
zP = np.dot(z, self._P)
zPz = np.einsum('ij,ij->i', zP, z)
zz = np.einsum('ij,ij->i', z, z)
return (zPz / zz).reshape(shape[:-1])
else:
# Call recursively for each pixel
return np.apply_along_axis(self, -1, X)
def main():
gdal.AllRegister()
path = auxil.select_directory('Input directory')
if path:
os.chdir(path)
# input image, convert to ENVI format
infile = auxil.select_infile(title='Image file')
if infile:
inDataset = gdal.Open(infile, GA_ReadOnly)
cols = inDataset.RasterXSize
rows = inDataset.RasterYSize
projection = inDataset.GetProjection()
geotransform = inDataset.GetGeoTransform()
driver = gdal.GetDriverByName('ENVI')
enviDataset=driver\
.CreateCopy('entmp',inDataset)
inDataset = None
enviDataset = None
else:
return
outfile, outfmt= \
auxil.select_outfilefmt(title='Output file')
# RX-algorithm
img = envi.open('entmp.hdr')
arr = img.load()
rx = RX(background=calc_stats(arr))
res = rx(arr)
# output
driver = gdal.GetDriverByName(outfmt)
outDataset = driver.Create(outfile,cols,rows,1,\
GDT_Float32)
if geotransform is not None:
outDataset.SetGeoTransform(geotransform)
if projection is not None:
outDataset.SetProjection(projection)
outBand = outDataset.GetRasterBand(1)
outBand.WriteArray(np.asarray(res, np.float32), 0, 0)
outBand.FlushCache()
outDataset = None
print 'Result written to %s' % outfile
def __call__(self, X):
'''Applies the RX anomaly detector to X.
Arguments:
`X` (numpy.ndarray):
For an image with shape (R, C, B), `X` can be a vector of
length B (single pixel) or an ndarray of shape (R, C, B) or
(R * C, B).
Returns numpy.ndarray or float:
The return value will be the RX detector score (squared Mahalanobis
distance) for each pixel given. If `X` is a single pixel, a float
will be returned; otherwise, the return value will be an ndarray
of floats with one less dimension than the input.
'''
from spectral.algorithms.algorithms import calc_stats
if not isinstance(X, np.ndarray):
raise TypeError('Expected a numpy.ndarray.')
if self.background is None:
self.set_background(calc_stats(X))
X = (X - self.background.mean)
C_1 = self.background.inv_cov
ndim = X.ndim
shape = X.shape
if ndim == 1:
return X.dot(C_1).dot(X)
if ndim == 3:
X = X.reshape((-1, X.shape[-1]))
A = X.dot(C_1)
r = np.einsum('ij,ij->i', A, X)
return r.reshape(shape[:-1])
def __call__(self, X):
'''Applies the RX anomaly detector to X.
Arguments:
`X` (numpy.ndarray):
For an image with shape (R, C, B), `X` can be a vector of
length B (single pixel) or an ndarray of shape (R, C, B) or
(R * C, B).
Returns numpy.ndarray or float:
The return value will be the RX detector score (squared Mahalanobis
distance) for each pixel given. If `X` is a single pixel, a float
will be returned; otherwise, the return value will be an ndarray
of floats with one less dimension than the input.
'''
from spectral.algorithms.algorithms import calc_stats
if not isinstance(X, np.ndarray):
raise TypeError('Expected a numpy.ndarray.')
if self.background is None:
self.set_background(calc_stats(X))
X = (X - self.background.mean)
C_1 = self.background.inv_cov
ndim = X.ndim
shape = X.shape
if ndim == 1:
return X.dot(C_1).dot(X)
if ndim == 3:
X = X.reshape((-1, X.shape[-1]))
A = X.dot(C_1)
r = np.einsum('ij,ij->i', A, X)
return r.reshape(shape[:-1])
def main():
gdal.AllRegister()
path = auxil.select_directory("Input directory")
if path:
os.chdir(path)
# input image, convert to ENVI format
infile = auxil.select_infile(title="Image file")
if infile:
inDataset = gdal.Open(infile, GA_ReadOnly)
cols = inDataset.RasterXSize
rows = inDataset.RasterYSize
projection = inDataset.GetProjection()
geotransform = inDataset.GetGeoTransform()
driver = gdal.GetDriverByName("ENVI")
enviDataset = driver.CreateCopy("entmp", inDataset)
inDataset = None
enviDataset = None
else:
return
outfile, outfmt = auxil.select_outfilefmt(title="Output file")
# RX-algorithm
img = envi.open("entmp.hdr")
arr = img.load()
rx = RX(background=calc_stats(arr))
res = rx(arr)
# output
driver = gdal.GetDriverByName(outfmt)
outDataset = driver.Create(outfile, cols, rows, 1, GDT_Float32)
if geotransform is not None:
outDataset.SetGeoTransform(geotransform)
if projection is not None:
outDataset.SetProjection(projection)
outBand = outDataset.GetRasterBand(1)
outBand.WriteArray(np.asarray(res, np.float32), 0, 0)
outBand.FlushCache()
outDataset = None
print "Result written to %s" % outfile
def matched_filter(X, target, background=None, window=None, cov=None):
r'''Computes a linear matched filter target detector score.
Usage:
y = matched_filter(X, target, background)
y = matched_filter(X, target, window=<win> [, cov=<cov>])
Given target/background means and a common covariance matrix, the matched
filter response is given by:
.. math::
y=\frac{(\mu_t-\mu_b)^T\Sigma^{-1}(x-\mu_b)}{(\mu_t-\mu_b)^T\Sigma^{-1}(\mu_t-\mu_b)}
where :math:`\mu_t` is the target mean, :math:`\mu_b` is the background
mean, and :math:`\Sigma` is the covariance.
Arguments:
`X` (numpy.ndarray):
For the first calling method shown, `X` can be an image with
shape (R, C, B) or an ndarray of shape (R * C, B). If the
`background` keyword is given, it will be used for the image
background statistics; otherwise, background statistics will be
computed from `X`.
If the `window` keyword is given, `X` must be a 3-dimensional
array and background statistics will be computed for each point
in the image using a local window defined by the keyword.
`target` (ndarray):
Length-K vector specifying the target to be detected.
`background` (`GaussianStats`):
The Gaussian statistics for the background (e.g., the result
of calling :func:`calc_stats` for an image). This argument is not
required if `window` is given.
`window` (2-tuple of odd integers):
Must have the form (`inner`, `outer`), where the two values
specify the widths (in pixels) of inner and outer windows centered
about the pixel being evaulated. Both values must be odd integers.
The background mean and covariance will be estimated from pixels
in the outer window, excluding pixels within the inner window. For
example, if (`inner`, `outer`) = (5, 21), then the number of
pixels used to estimate background statistics will be
:math:`21^2 - 5^2 = 416`. If this argument is given, `background`
is not required (and will be ignored, if given).
The window is modified near image borders, where full, centered
windows cannot be created. The outer window will be shifted, as
needed, to ensure that the outer window still has height and width
`outer` (in this situation, the pixel being evaluated will not be
at the center of the outer window). The inner window will be
clipped, as needed, near image borders. For example, assume an
image with 145 rows and columns. If the window used is
(5, 21), then for the image pixel at (0, 0) (upper left corner),
the the inner window will cover `image[:3, :3]` and the outer
window will cover `image[:21, :21]`. For the pixel at (50, 1), the
inner window will cover `image[48:53, :4]` and the outer window
will cover `image[40:51, :21]`.
`cov` (ndarray):
An optional covariance to use. If this parameter is given, `cov`
will be used for all matched filter calculations (background
covariance will not be recomputed in each window) and only the
background mean will be recomputed in each window. If the
`window` argument is specified, providing `cov` will allow the
result to be computed *much* faster.
Returns numpy.ndarray:
The return value will be the matched filter scores distance) for each
pixel given. If `X` has shape (R, C, K), the returned ndarray will
have shape (R, C).
'''
if background is not None and window is not None:
raise ValueError('`background` and `window` are mutually ' \
'exclusive arguments.')
if window is not None:
from .spatial import map_outer_window_stats
def mf_wrapper(bg, x):
return MatchedFilter(bg, target)(x)
return map_outer_window_stats(mf_wrapper, X, window[0], window[1],
dim_out=1, cov=cov)
else:
from spectral.algorithms.algorithms import calc_stats
if background is None:
background = calc_stats(X)
return MatchedFilter(background, target)(X)
def matched_filter(X, target, background=None, window=None, cov=None):
r'''Computes a linear matched filter target detector score.
Usage:
y = matched_filter(X, target, background)
y = matched_filter(X, target, window=<win> [, cov=<cov>])
Given target/background means and a common covariance matrix, the matched
filter response is given by:
.. math::
y=\frac{(\mu_t-\mu_b)^T\Sigma^{-1}(x-\mu_b)}{(\mu_t-\mu_b)^T\Sigma^{-1}(\mu_t-\mu_b)}
where :math:`\mu_t` is the target mean, :math:`\mu_b` is the background
mean, and :math:`\Sigma` is the covariance.
Arguments:
`X` (numpy.ndarray):
For the first calling method shown, `X` can be an image with
shape (R, C, B) or an ndarray of shape (R * C, B). If the
`background` keyword is given, it will be used for the image
background statistics; otherwise, background statistics will be
computed from `X`.
If the `window` keyword is given, `X` must be a 3-dimensional
array and background statistics will be computed for each point
in the image using a local window defined by the keyword.
`target` (ndarray):
Length-K vector specifying the target to be detected.
`background` (`GaussianStats`):
The Gaussian statistics for the background (e.g., the result
of calling :func:`calc_stats` for an image). This argument is not
required if `window` is given.
`window` (2-tuple of odd integers):
Must have the form (`inner`, `outer`), where the two values
specify the widths (in pixels) of inner and outer windows centered
about the pixel being evaulated. Both values must be odd integers.
The background mean and covariance will be estimated from pixels
in the outer window, excluding pixels within the inner window. For
example, if (`inner`, `outer`) = (5, 21), then the number of
pixels used to estimate background statistics will be
:math:`21^2 - 5^2 = 416`. If this argument is given, `background`
is not required (and will be ignored, if given).
The window is modified near image borders, where full, centered
windows cannot be created. The outer window will be shifted, as
needed, to ensure that the outer window still has height and width
`outer` (in this situation, the pixel being evaluated will not be
at the center of the outer window). The inner window will be
clipped, as needed, near image borders. For example, assume an
image with 145 rows and columns. If the window used is
(5, 21), then for the image pixel at (0, 0) (upper left corner),
the the inner window will cover `image[:3, :3]` and the outer
window will cover `image[:21, :21]`. For the pixel at (50, 1), the
inner window will cover `image[48:53, :4]` and the outer window
will cover `image[40:51, :21]`.
`cov` (ndarray):
An optional covariance to use. If this parameter is given, `cov`
will be used for all matched filter calculations (background
covariance will not be recomputed in each window). Only the
background mean will be recomputed in each window). If the
`window` argument is specified, providing `cov` will allow the
result to be computed *much* faster.
Returns numpy.ndarray:
The return value will be the matched filter scores distance) for each
pixel given. If `X` has shape (R, C, K), the returned ndarray will
have shape (R, C).
'''
if background is not None and window is not None:
raise ValueError('`background` and `window` are mutually ' \
'exclusive arguments.')
if window is not None:
from .spatial import map_outer_window_stats
def mf_wrapper(bg, x):
return MatchedFilter(bg, target)(x)
return map_outer_window_stats(mf_wrapper,
X,
window[0],
window[1],
dim_out=1,
cov=cov)
else:
from spectral.algorithms.algorithms import calc_stats
if background is None:
background = calc_stats(X)
return MatchedFilter(background, target)(X)
