747 lines
26 KiB
Python
747 lines
26 KiB
Python
|
# Copyright (C) 2003-2005 Peter J. Verveer
|
||
|
#
|
||
|
# Redistribution and use in source and binary forms, with or without
|
||
|
# modification, are permitted provided that the following conditions
|
||
|
# are met:
|
||
|
#
|
||
|
# 1. Redistributions of source code must retain the above copyright
|
||
|
# notice, this list of conditions and the following disclaimer.
|
||
|
#
|
||
|
# 2. Redistributions in binary form must reproduce the above
|
||
|
# copyright notice, this list of conditions and the following
|
||
|
# disclaimer in the documentation and/or other materials provided
|
||
|
# with the distribution.
|
||
|
#
|
||
|
# 3. The name of the author may not be used to endorse or promote
|
||
|
# products derived from this software without specific prior
|
||
|
# written permission.
|
||
|
#
|
||
|
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
|
||
|
# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||
|
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
|
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
|
||
|
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
|
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
|
||
|
# GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||
|
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
|
||
|
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
||
|
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
||
|
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
||
|
from __future__ import division, print_function, absolute_import
|
||
|
|
||
|
import itertools
|
||
|
import numpy
|
||
|
import warnings
|
||
|
|
||
|
from . import _ni_support
|
||
|
from . import _nd_image
|
||
|
from ._ni_docstrings import docdict
|
||
|
from scipy._lib import doccer
|
||
|
|
||
|
# Change the default 'reflect' to 'constant' via modifying a copy of docdict
|
||
|
docdict_copy = docdict.copy()
|
||
|
del docdict
|
||
|
docdict_copy['mode'] = docdict_copy['mode'].replace("Default is 'reflect'",
|
||
|
"Default is 'constant'")
|
||
|
|
||
|
docfiller = doccer.filldoc(docdict_copy)
|
||
|
|
||
|
__all__ = ['spline_filter1d', 'spline_filter', 'geometric_transform',
|
||
|
'map_coordinates', 'affine_transform', 'shift', 'zoom', 'rotate']
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def spline_filter1d(input, order=3, axis=-1, output=numpy.float64,
|
||
|
mode='mirror'):
|
||
|
"""
|
||
|
Calculate a one-dimensional spline filter along the given axis.
|
||
|
|
||
|
The lines of the array along the given axis are filtered by a
|
||
|
spline filter. The order of the spline must be >= 2 and <= 5.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
order : int, optional
|
||
|
The order of the spline, default is 3.
|
||
|
axis : int, optional
|
||
|
The axis along which the spline filter is applied. Default is the last
|
||
|
axis.
|
||
|
output : ndarray or dtype, optional
|
||
|
The array in which to place the output, or the dtype of the returned
|
||
|
array. Default is ``numpy.float64``.
|
||
|
%(mode)s
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
spline_filter1d : ndarray
|
||
|
The filtered input.
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
All functions in `ndimage.interpolation` do spline interpolation of
|
||
|
the input image. If using b-splines of `order > 1`, the input image
|
||
|
values have to be converted to b-spline coefficients first, which is
|
||
|
done by applying this one-dimensional filter sequentially along all
|
||
|
axes of the input. All functions that require b-spline coefficients
|
||
|
will automatically filter their inputs, a behavior controllable with
|
||
|
the `prefilter` keyword argument. For functions that accept a `mode`
|
||
|
parameter, the result will only be correct if it matches the `mode`
|
||
|
used when filtering.
|
||
|
"""
|
||
|
if order < 0 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
output = _ni_support._get_output(output, input)
|
||
|
if order in [0, 1]:
|
||
|
output[...] = numpy.array(input)
|
||
|
else:
|
||
|
mode = _ni_support._extend_mode_to_code(mode)
|
||
|
axis = _ni_support._check_axis(axis, input.ndim)
|
||
|
_nd_image.spline_filter1d(input, order, axis, output, mode)
|
||
|
return output
|
||
|
|
||
|
|
||
|
def spline_filter(input, order=3, output=numpy.float64, mode='mirror'):
|
||
|
"""
|
||
|
Multi-dimensional spline filter.
|
||
|
|
||
|
For more details, see `spline_filter1d`.
|
||
|
|
||
|
See Also
|
||
|
--------
|
||
|
spline_filter1d
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
The multi-dimensional filter is implemented as a sequence of
|
||
|
one-dimensional spline filters. The intermediate arrays are stored
|
||
|
in the same data type as the output. Therefore, for output types
|
||
|
with a limited precision, the results may be imprecise because
|
||
|
intermediate results may be stored with insufficient precision.
|
||
|
|
||
|
"""
|
||
|
if order < 2 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
output = _ni_support._get_output(output, input)
|
||
|
if order not in [0, 1] and input.ndim > 0:
|
||
|
for axis in range(input.ndim):
|
||
|
spline_filter1d(input, order, axis, output=output, mode=mode)
|
||
|
input = output
|
||
|
else:
|
||
|
output[...] = input[...]
|
||
|
return output
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def geometric_transform(input, mapping, output_shape=None,
|
||
|
output=None, order=3,
|
||
|
mode='constant', cval=0.0, prefilter=True,
|
||
|
extra_arguments=(), extra_keywords={}):
|
||
|
"""
|
||
|
Apply an arbitrary geometric transform.
|
||
|
|
||
|
The given mapping function is used to find, for each point in the
|
||
|
output, the corresponding coordinates in the input. The value of the
|
||
|
input at those coordinates is determined by spline interpolation of
|
||
|
the requested order.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
mapping : {callable, scipy.LowLevelCallable}
|
||
|
A callable object that accepts a tuple of length equal to the output
|
||
|
array rank, and returns the corresponding input coordinates as a tuple
|
||
|
of length equal to the input array rank.
|
||
|
output_shape : tuple of ints, optional
|
||
|
Shape tuple.
|
||
|
%(output)s
|
||
|
order : int, optional
|
||
|
The order of the spline interpolation, default is 3.
|
||
|
The order has to be in the range 0-5.
|
||
|
%(mode)s
|
||
|
%(cval)s
|
||
|
%(prefilter)s
|
||
|
extra_arguments : tuple, optional
|
||
|
Extra arguments passed to `mapping`.
|
||
|
extra_keywords : dict, optional
|
||
|
Extra keywords passed to `mapping`.
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
output : ndarray
|
||
|
The filtered input.
|
||
|
|
||
|
See Also
|
||
|
--------
|
||
|
map_coordinates, affine_transform, spline_filter1d
|
||
|
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
This function also accepts low-level callback functions with one
|
||
|
the following signatures and wrapped in `scipy.LowLevelCallable`:
|
||
|
|
||
|
.. code:: c
|
||
|
|
||
|
int mapping(npy_intp *output_coordinates, double *input_coordinates,
|
||
|
int output_rank, int input_rank, void *user_data)
|
||
|
int mapping(intptr_t *output_coordinates, double *input_coordinates,
|
||
|
int output_rank, int input_rank, void *user_data)
|
||
|
|
||
|
The calling function iterates over the elements of the output array,
|
||
|
calling the callback function at each element. The coordinates of the
|
||
|
current output element are passed through ``output_coordinates``. The
|
||
|
callback function must return the coordinates at which the input must
|
||
|
be interpolated in ``input_coordinates``. The rank of the input and
|
||
|
output arrays are given by ``input_rank`` and ``output_rank``
|
||
|
respectively. ``user_data`` is the data pointer provided
|
||
|
to `scipy.LowLevelCallable` as-is.
|
||
|
|
||
|
The callback function must return an integer error status that is zero
|
||
|
if something went wrong and one otherwise. If an error occurs, you should
|
||
|
normally set the python error status with an informative message
|
||
|
before returning, otherwise a default error message is set by the
|
||
|
calling function.
|
||
|
|
||
|
In addition, some other low-level function pointer specifications
|
||
|
are accepted, but these are for backward compatibility only and should
|
||
|
not be used in new code.
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> import numpy as np
|
||
|
>>> from scipy.ndimage import geometric_transform
|
||
|
>>> a = np.arange(12.).reshape((4, 3))
|
||
|
>>> def shift_func(output_coords):
|
||
|
... return (output_coords[0] - 0.5, output_coords[1] - 0.5)
|
||
|
...
|
||
|
>>> geometric_transform(a, shift_func)
|
||
|
array([[ 0. , 0. , 0. ],
|
||
|
[ 0. , 1.362, 2.738],
|
||
|
[ 0. , 4.812, 6.187],
|
||
|
[ 0. , 8.263, 9.637]])
|
||
|
|
||
|
>>> b = [1, 2, 3, 4, 5]
|
||
|
>>> def shift_func(output_coords):
|
||
|
... return (output_coords[0] - 3,)
|
||
|
...
|
||
|
>>> geometric_transform(b, shift_func, mode='constant')
|
||
|
array([0, 0, 0, 1, 2])
|
||
|
>>> geometric_transform(b, shift_func, mode='nearest')
|
||
|
array([1, 1, 1, 1, 2])
|
||
|
>>> geometric_transform(b, shift_func, mode='reflect')
|
||
|
array([3, 2, 1, 1, 2])
|
||
|
>>> geometric_transform(b, shift_func, mode='wrap')
|
||
|
array([2, 3, 4, 1, 2])
|
||
|
|
||
|
"""
|
||
|
if order < 0 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
if output_shape is None:
|
||
|
output_shape = input.shape
|
||
|
if input.ndim < 1 or len(output_shape) < 1:
|
||
|
raise RuntimeError('input and output rank must be > 0')
|
||
|
mode = _ni_support._extend_mode_to_code(mode)
|
||
|
if prefilter and order > 1:
|
||
|
filtered = spline_filter(input, order, output=numpy.float64)
|
||
|
else:
|
||
|
filtered = input
|
||
|
output = _ni_support._get_output(output, input, shape=output_shape)
|
||
|
_nd_image.geometric_transform(filtered, mapping, None, None, None, output,
|
||
|
order, mode, cval, extra_arguments,
|
||
|
extra_keywords)
|
||
|
return output
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def map_coordinates(input, coordinates, output=None, order=3,
|
||
|
mode='constant', cval=0.0, prefilter=True):
|
||
|
"""
|
||
|
Map the input array to new coordinates by interpolation.
|
||
|
|
||
|
The array of coordinates is used to find, for each point in the output,
|
||
|
the corresponding coordinates in the input. The value of the input at
|
||
|
those coordinates is determined by spline interpolation of the
|
||
|
requested order.
|
||
|
|
||
|
The shape of the output is derived from that of the coordinate
|
||
|
array by dropping the first axis. The values of the array along
|
||
|
the first axis are the coordinates in the input array at which the
|
||
|
output value is found.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
coordinates : array_like
|
||
|
The coordinates at which `input` is evaluated.
|
||
|
%(output)s
|
||
|
order : int, optional
|
||
|
The order of the spline interpolation, default is 3.
|
||
|
The order has to be in the range 0-5.
|
||
|
%(mode)s
|
||
|
%(cval)s
|
||
|
%(prefilter)s
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
map_coordinates : ndarray
|
||
|
The result of transforming the input. The shape of the output is
|
||
|
derived from that of `coordinates` by dropping the first axis.
|
||
|
|
||
|
See Also
|
||
|
--------
|
||
|
spline_filter, geometric_transform, scipy.interpolate
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> from scipy import ndimage
|
||
|
>>> a = np.arange(12.).reshape((4, 3))
|
||
|
>>> a
|
||
|
array([[ 0., 1., 2.],
|
||
|
[ 3., 4., 5.],
|
||
|
[ 6., 7., 8.],
|
||
|
[ 9., 10., 11.]])
|
||
|
>>> ndimage.map_coordinates(a, [[0.5, 2], [0.5, 1]], order=1)
|
||
|
array([ 2., 7.])
|
||
|
|
||
|
Above, the interpolated value of a[0.5, 0.5] gives output[0], while
|
||
|
a[2, 1] is output[1].
|
||
|
|
||
|
>>> inds = np.array([[0.5, 2], [0.5, 4]])
|
||
|
>>> ndimage.map_coordinates(a, inds, order=1, cval=-33.3)
|
||
|
array([ 2. , -33.3])
|
||
|
>>> ndimage.map_coordinates(a, inds, order=1, mode='nearest')
|
||
|
array([ 2., 8.])
|
||
|
>>> ndimage.map_coordinates(a, inds, order=1, cval=0, output=bool)
|
||
|
array([ True, False], dtype=bool)
|
||
|
|
||
|
"""
|
||
|
if order < 0 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
coordinates = numpy.asarray(coordinates)
|
||
|
if numpy.iscomplexobj(coordinates):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
output_shape = coordinates.shape[1:]
|
||
|
if input.ndim < 1 or len(output_shape) < 1:
|
||
|
raise RuntimeError('input and output rank must be > 0')
|
||
|
if coordinates.shape[0] != input.ndim:
|
||
|
raise RuntimeError('invalid shape for coordinate array')
|
||
|
mode = _ni_support._extend_mode_to_code(mode)
|
||
|
if prefilter and order > 1:
|
||
|
filtered = spline_filter(input, order, output=numpy.float64)
|
||
|
else:
|
||
|
filtered = input
|
||
|
output = _ni_support._get_output(output, input,
|
||
|
shape=output_shape)
|
||
|
_nd_image.geometric_transform(filtered, None, coordinates, None, None,
|
||
|
output, order, mode, cval, None, None)
|
||
|
return output
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def affine_transform(input, matrix, offset=0.0, output_shape=None,
|
||
|
output=None, order=3,
|
||
|
mode='constant', cval=0.0, prefilter=True):
|
||
|
"""
|
||
|
Apply an affine transformation.
|
||
|
|
||
|
Given an output image pixel index vector ``o``, the pixel value
|
||
|
is determined from the input image at position
|
||
|
``np.dot(matrix, o) + offset``.
|
||
|
|
||
|
This does 'pull' (or 'backward') resampling, transforming the output space
|
||
|
to the input to locate data. Affine transformations are often described in
|
||
|
the 'push' (or 'forward') direction, transforming input to output. If you
|
||
|
have a matrix for the 'push' transformation, use its inverse
|
||
|
(:func:`numpy.linalg.inv`) in this function.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
matrix : ndarray
|
||
|
The inverse coordinate transformation matrix, mapping output
|
||
|
coordinates to input coordinates. If ``ndim`` is the number of
|
||
|
dimensions of ``input``, the given matrix must have one of the
|
||
|
following shapes:
|
||
|
|
||
|
- ``(ndim, ndim)``: the linear transformation matrix for each
|
||
|
output coordinate.
|
||
|
- ``(ndim,)``: assume that the 2D transformation matrix is
|
||
|
diagonal, with the diagonal specified by the given value. A more
|
||
|
efficient algorithm is then used that exploits the separability
|
||
|
of the problem.
|
||
|
- ``(ndim + 1, ndim + 1)``: assume that the transformation is
|
||
|
specified using homogeneous coordinates [1]_. In this case, any
|
||
|
value passed to ``offset`` is ignored.
|
||
|
- ``(ndim, ndim + 1)``: as above, but the bottom row of a
|
||
|
homogeneous transformation matrix is always ``[0, 0, ..., 1]``,
|
||
|
and may be omitted.
|
||
|
|
||
|
offset : float or sequence, optional
|
||
|
The offset into the array where the transform is applied. If a float,
|
||
|
`offset` is the same for each axis. If a sequence, `offset` should
|
||
|
contain one value for each axis.
|
||
|
output_shape : tuple of ints, optional
|
||
|
Shape tuple.
|
||
|
%(output)s
|
||
|
order : int, optional
|
||
|
The order of the spline interpolation, default is 3.
|
||
|
The order has to be in the range 0-5.
|
||
|
%(mode)s
|
||
|
%(cval)s
|
||
|
%(prefilter)s
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
affine_transform : ndarray
|
||
|
The transformed input.
|
||
|
|
||
|
Notes
|
||
|
-----
|
||
|
The given matrix and offset are used to find for each point in the
|
||
|
output the corresponding coordinates in the input by an affine
|
||
|
transformation. The value of the input at those coordinates is
|
||
|
determined by spline interpolation of the requested order. Points
|
||
|
outside the boundaries of the input are filled according to the given
|
||
|
mode.
|
||
|
|
||
|
.. versionchanged:: 0.18.0
|
||
|
Previously, the exact interpretation of the affine transformation
|
||
|
depended on whether the matrix was supplied as a one-dimensional or
|
||
|
two-dimensional array. If a one-dimensional array was supplied
|
||
|
to the matrix parameter, the output pixel value at index ``o``
|
||
|
was determined from the input image at position
|
||
|
``matrix * (o + offset)``.
|
||
|
|
||
|
References
|
||
|
----------
|
||
|
.. [1] https://en.wikipedia.org/wiki/Homogeneous_coordinates
|
||
|
"""
|
||
|
if order < 0 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
if output_shape is None:
|
||
|
output_shape = input.shape
|
||
|
if input.ndim < 1 or len(output_shape) < 1:
|
||
|
raise RuntimeError('input and output rank must be > 0')
|
||
|
mode = _ni_support._extend_mode_to_code(mode)
|
||
|
if prefilter and order > 1:
|
||
|
filtered = spline_filter(input, order, output=numpy.float64)
|
||
|
else:
|
||
|
filtered = input
|
||
|
output = _ni_support._get_output(output, input,
|
||
|
shape=output_shape)
|
||
|
matrix = numpy.asarray(matrix, dtype=numpy.float64)
|
||
|
if matrix.ndim not in [1, 2] or matrix.shape[0] < 1:
|
||
|
raise RuntimeError('no proper affine matrix provided')
|
||
|
if (matrix.ndim == 2 and matrix.shape[1] == input.ndim + 1 and
|
||
|
(matrix.shape[0] in [input.ndim, input.ndim + 1])):
|
||
|
if matrix.shape[0] == input.ndim + 1:
|
||
|
exptd = [0] * input.ndim + [1]
|
||
|
if not numpy.all(matrix[input.ndim] == exptd):
|
||
|
msg = ('Expected homogeneous transformation matrix with '
|
||
|
'shape %s for image shape %s, but bottom row was '
|
||
|
'not equal to %s' % (matrix.shape, input.shape, exptd))
|
||
|
raise ValueError(msg)
|
||
|
# assume input is homogeneous coordinate transformation matrix
|
||
|
offset = matrix[:input.ndim, input.ndim]
|
||
|
matrix = matrix[:input.ndim, :input.ndim]
|
||
|
if matrix.shape[0] != input.ndim:
|
||
|
raise RuntimeError('affine matrix has wrong number of rows')
|
||
|
if matrix.ndim == 2 and matrix.shape[1] != output.ndim:
|
||
|
raise RuntimeError('affine matrix has wrong number of columns')
|
||
|
if not matrix.flags.contiguous:
|
||
|
matrix = matrix.copy()
|
||
|
offset = _ni_support._normalize_sequence(offset, input.ndim)
|
||
|
offset = numpy.asarray(offset, dtype=numpy.float64)
|
||
|
if offset.ndim != 1 or offset.shape[0] < 1:
|
||
|
raise RuntimeError('no proper offset provided')
|
||
|
if not offset.flags.contiguous:
|
||
|
offset = offset.copy()
|
||
|
if matrix.ndim == 1:
|
||
|
warnings.warn(
|
||
|
"The behaviour of affine_transform with a one-dimensional "
|
||
|
"array supplied for the matrix parameter has changed in "
|
||
|
"scipy 0.18.0."
|
||
|
)
|
||
|
_nd_image.zoom_shift(filtered, matrix, offset/matrix, output, order,
|
||
|
mode, cval)
|
||
|
else:
|
||
|
_nd_image.geometric_transform(filtered, None, None, matrix, offset,
|
||
|
output, order, mode, cval, None, None)
|
||
|
return output
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def shift(input, shift, output=None, order=3, mode='constant', cval=0.0,
|
||
|
prefilter=True):
|
||
|
"""
|
||
|
Shift an array.
|
||
|
|
||
|
The array is shifted using spline interpolation of the requested order.
|
||
|
Points outside the boundaries of the input are filled according to the
|
||
|
given mode.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
shift : float or sequence
|
||
|
The shift along the axes. If a float, `shift` is the same for each
|
||
|
axis. If a sequence, `shift` should contain one value for each axis.
|
||
|
%(output)s
|
||
|
order : int, optional
|
||
|
The order of the spline interpolation, default is 3.
|
||
|
The order has to be in the range 0-5.
|
||
|
%(mode)s
|
||
|
%(cval)s
|
||
|
%(prefilter)s
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
shift : ndarray
|
||
|
The shifted input.
|
||
|
|
||
|
"""
|
||
|
if order < 0 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
if input.ndim < 1:
|
||
|
raise RuntimeError('input and output rank must be > 0')
|
||
|
mode = _ni_support._extend_mode_to_code(mode)
|
||
|
if prefilter and order > 1:
|
||
|
filtered = spline_filter(input, order, output=numpy.float64)
|
||
|
else:
|
||
|
filtered = input
|
||
|
output = _ni_support._get_output(output, input)
|
||
|
shift = _ni_support._normalize_sequence(shift, input.ndim)
|
||
|
shift = [-ii for ii in shift]
|
||
|
shift = numpy.asarray(shift, dtype=numpy.float64)
|
||
|
if not shift.flags.contiguous:
|
||
|
shift = shift.copy()
|
||
|
_nd_image.zoom_shift(filtered, None, shift, output, order, mode, cval)
|
||
|
return output
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def zoom(input, zoom, output=None, order=3, mode='constant', cval=0.0,
|
||
|
prefilter=True):
|
||
|
"""
|
||
|
Zoom an array.
|
||
|
|
||
|
The array is zoomed using spline interpolation of the requested order.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
zoom : float or sequence
|
||
|
The zoom factor along the axes. If a float, `zoom` is the same for each
|
||
|
axis. If a sequence, `zoom` should contain one value for each axis.
|
||
|
%(output)s
|
||
|
order : int, optional
|
||
|
The order of the spline interpolation, default is 3.
|
||
|
The order has to be in the range 0-5.
|
||
|
%(mode)s
|
||
|
%(cval)s
|
||
|
%(prefilter)s
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
zoom : ndarray
|
||
|
The zoomed input.
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> from scipy import ndimage, misc
|
||
|
>>> import matplotlib.pyplot as plt
|
||
|
|
||
|
>>> fig = plt.figure()
|
||
|
>>> ax1 = fig.add_subplot(121) # left side
|
||
|
>>> ax2 = fig.add_subplot(122) # right side
|
||
|
>>> ascent = misc.ascent()
|
||
|
>>> result = ndimage.zoom(ascent, 3.0)
|
||
|
>>> ax1.imshow(ascent)
|
||
|
>>> ax2.imshow(result)
|
||
|
>>> plt.show()
|
||
|
|
||
|
>>> print(ascent.shape)
|
||
|
(512, 512)
|
||
|
|
||
|
>>> print(result.shape)
|
||
|
(1536, 1536)
|
||
|
"""
|
||
|
if order < 0 or order > 5:
|
||
|
raise RuntimeError('spline order not supported')
|
||
|
input = numpy.asarray(input)
|
||
|
if numpy.iscomplexobj(input):
|
||
|
raise TypeError('Complex type not supported')
|
||
|
if input.ndim < 1:
|
||
|
raise RuntimeError('input and output rank must be > 0')
|
||
|
mode = _ni_support._extend_mode_to_code(mode)
|
||
|
if prefilter and order > 1:
|
||
|
filtered = spline_filter(input, order, output=numpy.float64)
|
||
|
else:
|
||
|
filtered = input
|
||
|
zoom = _ni_support._normalize_sequence(zoom, input.ndim)
|
||
|
output_shape = tuple(
|
||
|
[int(round(ii * jj)) for ii, jj in zip(input.shape, zoom)])
|
||
|
|
||
|
zoom_div = numpy.array(output_shape, float) - 1
|
||
|
# Zooming to infinite values is unpredictable, so just choose
|
||
|
# zoom factor 1 instead
|
||
|
zoom = numpy.divide(numpy.array(input.shape) - 1, zoom_div,
|
||
|
out=numpy.ones_like(input.shape, dtype=numpy.float64),
|
||
|
where=zoom_div != 0)
|
||
|
|
||
|
output = _ni_support._get_output(output, input,
|
||
|
shape=output_shape)
|
||
|
zoom = numpy.ascontiguousarray(zoom)
|
||
|
_nd_image.zoom_shift(filtered, zoom, None, output, order, mode, cval)
|
||
|
return output
|
||
|
|
||
|
|
||
|
@docfiller
|
||
|
def rotate(input, angle, axes=(1, 0), reshape=True, output=None, order=3,
|
||
|
mode='constant', cval=0.0, prefilter=True):
|
||
|
"""
|
||
|
Rotate an array.
|
||
|
|
||
|
The array is rotated in the plane defined by the two axes given by the
|
||
|
`axes` parameter using spline interpolation of the requested order.
|
||
|
|
||
|
Parameters
|
||
|
----------
|
||
|
%(input)s
|
||
|
angle : float
|
||
|
The rotation angle in degrees.
|
||
|
axes : tuple of 2 ints, optional
|
||
|
The two axes that define the plane of rotation. Default is the first
|
||
|
two axes.
|
||
|
reshape : bool, optional
|
||
|
If `reshape` is true, the output shape is adapted so that the input
|
||
|
array is contained completely in the output. Default is True.
|
||
|
%(output)s
|
||
|
order : int, optional
|
||
|
The order of the spline interpolation, default is 3.
|
||
|
The order has to be in the range 0-5.
|
||
|
%(mode)s
|
||
|
%(cval)s
|
||
|
%(prefilter)s
|
||
|
|
||
|
Returns
|
||
|
-------
|
||
|
rotate : ndarray
|
||
|
The rotated input.
|
||
|
|
||
|
Examples
|
||
|
--------
|
||
|
>>> from scipy import ndimage, misc
|
||
|
>>> import matplotlib.pyplot as plt
|
||
|
>>> fig = plt.figure(figsize=(10, 3))
|
||
|
>>> ax1, ax2, ax3 = fig.subplots(1, 3)
|
||
|
>>> img = misc.ascent()
|
||
|
>>> img_45 = ndimage.rotate(img, 45, reshape=False)
|
||
|
>>> full_img_45 = ndimage.rotate(img, 45, reshape=True)
|
||
|
>>> ax1.imshow(img, cmap='gray')
|
||
|
>>> ax1.set_axis_off()
|
||
|
>>> ax2.imshow(img_45, cmap='gray')
|
||
|
>>> ax2.set_axis_off()
|
||
|
>>> ax3.imshow(full_img_45, cmap='gray')
|
||
|
>>> ax3.set_axis_off()
|
||
|
>>> fig.set_tight_layout(True)
|
||
|
>>> plt.show()
|
||
|
>>> print(img.shape)
|
||
|
(512, 512)
|
||
|
>>> print(img_45.shape)
|
||
|
(512, 512)
|
||
|
>>> print(full_img_45.shape)
|
||
|
(724, 724)
|
||
|
|
||
|
"""
|
||
|
input_arr = numpy.asarray(input)
|
||
|
ndim = input_arr.ndim
|
||
|
|
||
|
if ndim < 2:
|
||
|
raise ValueError('input array should be at least two-dimensional')
|
||
|
|
||
|
axes = list(axes)
|
||
|
|
||
|
if len(axes) != 2:
|
||
|
raise ValueError('axes should contain exactly two values')
|
||
|
|
||
|
if not all([float(ax).is_integer() for ax in axes]):
|
||
|
raise ValueError('axes should contain only integer values')
|
||
|
|
||
|
if axes[0] < 0:
|
||
|
axes[0] += ndim
|
||
|
if axes[1] < 0:
|
||
|
axes[1] += ndim
|
||
|
if axes[0] < 0 or axes[1] < 0 or axes[0] >= ndim or axes[1] >= ndim:
|
||
|
raise ValueError('invalid rotation plane specified')
|
||
|
|
||
|
axes.sort()
|
||
|
|
||
|
angle_rad = numpy.deg2rad(angle)
|
||
|
c, s = numpy.cos(angle_rad), numpy.sin(angle_rad)
|
||
|
|
||
|
rot_matrix = numpy.array([[c, s],
|
||
|
[-s, c]])
|
||
|
|
||
|
img_shape = numpy.asarray(input_arr.shape)
|
||
|
in_plane_shape = img_shape[axes]
|
||
|
if reshape:
|
||
|
# Compute transformed input bounds
|
||
|
iy, ix = in_plane_shape
|
||
|
out_bounds = rot_matrix @ [[0, 0, iy, iy],
|
||
|
[0, ix, 0, ix]]
|
||
|
# Compute the shape of the transformed input plane
|
||
|
out_plane_shape = (out_bounds.ptp(axis=1) + 0.5).astype(int)
|
||
|
else:
|
||
|
out_plane_shape = img_shape[axes]
|
||
|
|
||
|
out_center = rot_matrix @ ((out_plane_shape - 1) / 2)
|
||
|
in_center = (in_plane_shape - 1) / 2
|
||
|
offset = in_center - out_center
|
||
|
|
||
|
output_shape = img_shape
|
||
|
output_shape[axes] = out_plane_shape
|
||
|
output_shape = tuple(output_shape)
|
||
|
|
||
|
output = _ni_support._get_output(output, input_arr, shape=output_shape)
|
||
|
|
||
|
if ndim <= 2:
|
||
|
affine_transform(input_arr, rot_matrix, offset, output_shape, output,
|
||
|
order, mode, cval, prefilter)
|
||
|
else:
|
||
|
# If ndim > 2, the rotation is applied over all the planes
|
||
|
# parallel to axes
|
||
|
planes_coord = itertools.product(
|
||
|
*[[slice(None)] if ax in axes else range(img_shape[ax])
|
||
|
for ax in range(ndim)])
|
||
|
|
||
|
out_plane_shape = tuple(out_plane_shape)
|
||
|
|
||
|
for coordinates in planes_coord:
|
||
|
ia = input_arr[coordinates]
|
||
|
oa = output[coordinates]
|
||
|
affine_transform(ia, rot_matrix, offset, out_plane_shape,
|
||
|
oa, order, mode, cval, prefilter)
|
||
|
|
||
|
return output
|