def _binary_erosion(input,
structure,
iterations,
mask,
output,
border_value,
origin,
invert,
brute_force=True):
try:
iterations = operator.index(iterations)
except TypeError:
raise TypeError('iterations parameter should be an integer')
if input.dtype.kind == 'c':
raise TypeError('Complex type not supported')
if structure is None:
structure = generate_binary_structure(input.ndim, 1)
all_weights_nonzero = input.ndim == 1
center_is_true = True
default_structure = True
else:
structure = structure.astype(dtype=bool, copy=False)
# transfer to CPU for use in determining if it is fully dense
# structure_cpu = cupy.asnumpy(structure)
default_structure = False
if structure.ndim != input.ndim:
raise RuntimeError('structure and input must have same dimensionality')
if not structure.flags.c_contiguous:
structure = cupy.ascontiguousarray(structure)
if structure.size < 1:
raise RuntimeError('structure must not be empty')
if mask is not None:
if mask.shape != input.shape:
raise RuntimeError('mask and input must have equal sizes')
if not mask.flags.c_contiguous:
mask = cupy.ascontiguousarray(mask)
masked = True
else:
masked = False
origin = _util._fix_sequence_arg(origin, input.ndim, 'origin', int)
if isinstance(output, cupy.ndarray):
if output.dtype.kind == 'c':
raise TypeError('Complex output type not supported')
else:
output = bool
output = _util._get_output(output, input)
temp_needed = cupy.shares_memory(output, input, 'MAY_SHARE_BOUNDS')
if temp_needed:
# input and output arrays cannot share memory
temp = output
output = _util._get_output(output.dtype, input)
if structure.ndim == 0:
# kernel doesn't handle ndim=0, so special case it here
if float(structure):
output[...] = cupy.asarray(input, dtype=bool)
else:
output[...] = ~cupy.asarray(input, dtype=bool)
return output
origin = tuple(origin)
int_type = _util._get_inttype(input)
offsets = _filters_core._origins_to_offsets(origin, structure.shape)
if not default_structure:
# synchronize required to determine if all weights are non-zero
nnz = int(cupy.count_nonzero(structure))
all_weights_nonzero = nnz == structure.size
if all_weights_nonzero:
center_is_true = True
else:
center_is_true = _center_is_true(structure, origin)
erode_kernel = _get_binary_erosion_kernel(
structure.shape,
int_type,
offsets,
center_is_true,
border_value,
invert,
masked,
all_weights_nonzero,
)
if iterations == 1:
if masked:
output = erode_kernel(input, structure, mask, output)
else:
output = erode_kernel(input, structure, output)
elif center_is_true and not brute_force:
raise NotImplementedError(
'only brute_force iteration has been implemented')
else:
if cupy.shares_memory(output, input, 'MAY_SHARE_BOUNDS'):
raise ValueError('output and input may not overlap in memory')
tmp_in = cupy.empty_like(input, dtype=output.dtype)
tmp_out = output
if iterations >= 1 and not iterations & 1:
tmp_in, tmp_out = tmp_out, tmp_in
if masked:
tmp_out = erode_kernel(input, structure, mask, tmp_out)
else:
tmp_out = erode_kernel(input, structure, tmp_out)
# TODO: kernel doesn't return the changed status, so determine it here
changed = not (input == tmp_out).all() # synchronize!
ii = 1
while ii < iterations or ((iterations < 1) and changed):
tmp_in, tmp_out = tmp_out, tmp_in
if masked:
tmp_out = erode_kernel(tmp_in, structure, mask, tmp_out)
else:
tmp_out = erode_kernel(tmp_in, structure, tmp_out)
changed = not (tmp_in == tmp_out).all()
ii += 1
if not changed and (not ii & 1): # synchronize!
# can exit early if nothing changed
# (only do this after even number of tmp_in/out swaps)
break
output = tmp_out
if temp_needed:
temp[...] = output
output = temp
return output
def binary_hit_or_miss(input,
structure1=None,
structure2=None,
output=None,
origin1=0,
origin2=None):
"""
Multidimensional binary hit-or-miss transform.
The hit-or-miss transform finds the locations of a given pattern
inside the input image.
Args:
input (cupy.ndarray): Binary image where a pattern is to be detected.
structure1 (cupy.ndarray, optional): Part of the structuring element to
be fitted to the foreground (non-zero elements) of ``input``. If no
value is provided, a structure of square connectivity 1 is chosen.
structure2 (cupy.ndarray, optional): Second part of the structuring
element that has to miss completely the foreground. If no value is
provided, the complementary of ``structure1`` is taken.
output (cupy.ndarray, dtype or None, optional): Array of the same shape
as input, into which the output is placed. By default, a new array
is created.
origin1 (int or tuple of ints, optional): Placement of the first part
of the structuring element ``structure1``, by default 0 for a
centered structure.
origin2 (int or tuple of ints or None, optional): Placement of the
second part of the structuring element ``structure2``, by default 0
for a centered structure. If a value is provided for ``origin1``
and not for ``origin2``, then ``origin2`` is set to ``origin1``.
Returns:
cupy.ndarray: Hit-or-miss transform of ``input`` with the given
structuring element (``structure1``, ``structure2``).
.. warning::
This function may synchronize the device.
.. seealso:: :func:`scipy.ndimage.binary_hit_or_miss`
"""
if structure1 is None:
structure1 = generate_binary_structure(input.ndim, 1)
if structure2 is None:
structure2 = cupy.logical_not(structure1)
origin1 = _util._fix_sequence_arg(origin1, input.ndim, 'origin1', int)
if origin2 is None:
origin2 = origin1
else:
origin2 = _util._fix_sequence_arg(origin2, input.ndim, 'origin2', int)
tmp1 = _binary_erosion(input, structure1, 1, None, None, 0, origin1, 0,
False)
inplace = isinstance(output, cupy.ndarray)
result = _binary_erosion(input, structure2, 1, None, output, 0, origin2, 1,
False)
if inplace:
cupy.logical_not(output, output)
cupy.logical_and(tmp1, output, output)
else:
cupy.logical_not(result, result)
return cupy.logical_and(tmp1, result)
def grey_dilation(input,
size=None,
footprint=None,
structure=None,
output=None,
mode='reflect',
cval=0.0,
origin=0):
"""Calculates a greyscale dilation.
Args:
input (cupy.ndarray): The input array.
size (tuple of ints): Shape of a flat and full structuring element used
for the greyscale dilation. Optional if ``footprint`` or
``structure`` is provided.
footprint (array of ints): Positions of non-infinite elements of a flat
structuring element used for greyscale dilation. Non-zero values
give the set of neighbors of the center over which maximum is
chosen.
structure (array of ints): Structuring element used for the greyscale
dilation. ``structure`` may be a non-flat structuring element.
output (cupy.ndarray, dtype or None): The array in which to place the
output.
mode (str): The array borders are handled according to the given mode
(``'reflect'``, ``'constant'``, ``'nearest'``, ``'mirror'``,
``'wrap'``). Default is ``'reflect'``.
cval (scalar): Value to fill past edges of input if mode is
``constant``. Default is ``0.0``.
origin (scalar or tuple of scalar): The origin parameter controls the
placement of the filter, relative to the center of the current
element of the input. Default of 0 is equivalent to
``(0,)*input.ndim``.
Returns:
cupy.ndarray: The result of greyscale dilation.
.. seealso:: :func:`scipy.ndimage.grey_dilation`
"""
if size is None and footprint is None and structure is None:
raise ValueError('size, footprint or structure must be specified')
if structure is not None:
structure = cupy.array(structure)
structure = structure[tuple([slice(None, None, -1)] * structure.ndim)]
if footprint is not None:
footprint = cupy.array(footprint)
footprint = footprint[tuple([slice(None, None, -1)] * footprint.ndim)]
origin = _util._fix_sequence_arg(origin, input.ndim, 'origin', int)
for i in range(len(origin)):
origin[i] = -origin[i]
if footprint is not None:
sz = footprint.shape[i]
elif structure is not None:
sz = structure.shape[i]
elif numpy.isscalar(size):
sz = size
else:
sz = size[i]
if sz % 2 == 0:
origin[i] -= 1
return filters._min_or_max_filter(input, size, footprint, structure,
output, mode, cval, origin, 'max')
def fourier_ellipsoid(input, size, n=-1, axis=-1, output=None):
"""Multidimensional ellipsoid Fourier filter.
The array is multiplied with the fourier transform of a ellipsoid of
given sizes.
Args:
input (cupy.ndarray): The input array.
size (float or sequence of float): The size of the box used for
filtering. If a float, `size` is the same for all axes. If a
sequence, `size` has to contain one value for each axis.
n (int, optional): If `n` is negative (default), then the input is
assumed to be the result of a complex fft. If `n` is larger than or
equal to zero, the input is assumed to be the result of a real fft,
and `n` gives the length of the array before transformation along
the real transform direction.
axis (int, optional): The axis of the real transform (only used when
``n > -1``).
output (cupy.ndarray, optional):
If given, the result of shifting the input is placed in this array.
Returns:
output (cupy.ndarray): The filtered output.
"""
ndim = input.ndim
if ndim == 1:
return fourier_uniform(input, size, n, axis, output)
if ndim > 3:
# Note: SciPy currently does not do any filtering on >=4d inputs, but
# does not warn about this!
raise NotImplementedError('Only 1d, 2d and 3d inputs are supported')
output = _get_output_fourier(output, input)
axis = internal._normalize_axis_index(axis, ndim)
sizes = _util._fix_sequence_arg(size, ndim, 'size')
_core.elementwise_copy(input, output)
# compute the distance from the origin for all samples in Fourier space
distance = 0
for ax, (size, ax_size) in enumerate(zip(sizes, output.shape)):
# compute the frequency grid in Hz
if ax == axis and n > 0:
arr = cupy.arange(ax_size, dtype=output.real.dtype)
arr *= numpy.pi * size / n
else:
arr = cupy.fft.fftfreq(ax_size)
arr *= numpy.pi * size
arr = arr.astype(output.real.dtype, copy=False)
arr *= arr
arr = _reshape_nd(arr, ndim=ndim, axis=ax)
distance = distance + arr
cupy.sqrt(distance, out=distance)
if ndim == 2:
special.j1(distance, out=output)
output *= 2
output /= distance
elif ndim == 3:
cupy.sin(distance, out=output)
output -= distance * cupy.cos(distance)
output *= 3
output /= distance**3
output[(0, ) * ndim] = 1.0 # avoid NaN in corner at frequency=0 location
output *= input
return output
def zoom(input,
zoom,
output=None,
order=3,
mode='constant',
cval=0.0,
prefilter=True,
*,
grid_mode=False):
"""Zoom an array.
The array is zoomed using spline interpolation of the requested order.
Args:
input (cupy.ndarray): The input array.
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 (cupy.ndarray or ~cupy.dtype): The array in which to place the
output, or the dtype of the returned array.
order (int): The order of the spline interpolation, default is 3. Must
be in the range 0-5.
mode (str): Points outside the boundaries of the input are filled
according to the given mode (``'constant'``, ``'nearest'``,
``'mirror'``, ``'reflect'``, ``'wrap'``, ``'grid-mirror'``,
``'grid-wrap'``, ``'grid-constant'`` or ``'opencv'``).
cval (scalar): Value used for points outside the boundaries of
the input if ``mode='constant'`` or ``mode='opencv'``. Default is
0.0
prefilter (bool): It is not used yet. It just exists for compatibility
with :mod:`scipy.ndimage`.
grid_mode (bool, optional): If False, the distance from the pixel
centers is zoomed. Otherwise, the distance including the full pixel
extent is used. For example, a 1d signal of length 5 is considered
to have length 4 when ``grid_mode`` is False, but length 5 when
``grid_mode`` is True. See the following visual illustration:
.. code-block:: text
| pixel 1 | pixel 2 | pixel 3 | pixel 4 | pixel 5 |
|<-------------------------------------->|
vs.
|<----------------------------------------------->|
The starting point of the arrow in the diagram above corresponds to
coordinate location 0 in each mode.
Returns:
cupy.ndarray or None:
The zoomed input.
.. seealso:: :func:`scipy.ndimage.zoom`
"""
_check_parameter('zoom', order, mode)
zoom = _util._fix_sequence_arg(zoom, input.ndim, 'zoom', float)
output_shape = []
for s, z in zip(input.shape, zoom):
output_shape.append(int(round(s * z)))
output_shape = tuple(output_shape)
if mode == 'opencv':
zoom = []
offset = []
for in_size, out_size in zip(input.shape, output_shape):
if out_size > 1:
zoom.append(float(in_size) / out_size)
offset.append((zoom[-1] - 1) / 2.0)
else:
zoom.append(0)
offset.append(0)
mode = 'nearest'
output = affine_transform(
input,
cupy.asarray(zoom),
offset,
output_shape,
output,
order,
mode,
cval,
prefilter,
)
else:
if grid_mode:
# warn about modes that may have surprising behavior
suggest_mode = None
if mode == 'constant':
suggest_mode = 'grid-constant'
elif mode == 'wrap':
suggest_mode = 'grid-wrap'
if suggest_mode is not None:
warnings.warn(
f'It is recommended to use mode = {suggest_mode} instead '
f'of {mode} when grid_mode is True.')
zoom = []
for in_size, out_size in zip(input.shape, output_shape):
if grid_mode and out_size > 0:
zoom.append(in_size / out_size)
elif out_size > 1:
zoom.append((in_size - 1) / (out_size - 1))
else:
zoom.append(0)
output = _util._get_output(output, input, shape=output_shape)
if input.dtype.kind in 'iu':
input = input.astype(cupy.float32)
filtered, nprepad = _filter_input(input, prefilter, mode, cval, order)
integer_output = output.dtype.kind in 'iu'
_util._check_cval(mode, cval, integer_output)
large_int = max(_prod(input.shape), _prod(output_shape)) > 1 << 31
kern = _interp_kernels._get_zoom_kernel(input.ndim,
large_int,
output_shape,
mode,
order=order,
integer_output=integer_output,
grid_mode=grid_mode,
nprepad=nprepad)
zoom = cupy.asarray(zoom, dtype=cupy.float64)
kern(filtered, zoom, output)
return output
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.
Args:
input (cupy.ndarray): The input array.
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 (cupy.ndarray or ~cupy.dtype): The array in which to place the
output, or the dtype of the returned array.
order (int): The order of the spline interpolation, default is 3. Must
be in the range 0-5.
mode (str): Points outside the boundaries of the input are filled
according to the given mode (``'constant'``, ``'nearest'``,
``'mirror'``, ``'reflect'``, ``'wrap'``, ``'grid-mirror'``,
``'grid-wrap'``, ``'grid-constant'`` or ``'opencv'``).
cval (scalar): Value used for points outside the boundaries of
the input if ``mode='constant'`` or ``mode='opencv'``. Default is
0.0
prefilter (bool): It is not used yet. It just exists for compatibility
with :mod:`scipy.ndimage`.
Returns:
cupy.ndarray or None:
The shifted input.
.. seealso:: :func:`scipy.ndimage.shift`
"""
_check_parameter('shift', order, mode)
shift = _util._fix_sequence_arg(shift, input.ndim, 'shift', float)
if mode == 'opencv':
mode = '_opencv_edge'
output = affine_transform(
input,
cupy.ones(input.ndim, input.dtype),
cupy.negative(cupy.asarray(shift)),
None,
output,
order,
mode,
cval,
prefilter,
)
else:
output = _util._get_output(output, input)
if input.dtype.kind in 'iu':
input = input.astype(cupy.float32)
filtered, nprepad = _filter_input(input, prefilter, mode, cval, order)
integer_output = output.dtype.kind in 'iu'
_util._check_cval(mode, cval, integer_output)
large_int = _prod(input.shape) > 1 << 31
kern = _interp_kernels._get_shift_kernel(input.ndim,
large_int,
input.shape,
mode,
cval=cval,
order=order,
integer_output=integer_output,
nprepad=nprepad)
shift = cupy.asarray(shift, dtype=cupy.float64, order='C')
if shift.ndim != 1:
raise ValueError('shift must be 1d')
if shift.size != filtered.ndim:
raise ValueError('len(shift) must equal input.ndim')
kern(filtered, shift, output)
return output
def affine_transform(input,
matrix,
offset=0.0,
output_shape=None,
output=None,
order=3,
mode='constant',
cval=0.0,
prefilter=True,
*,
texture_memory=False):
"""Apply an affine transformation.
Given an output image pixel index vector ``o``, the pixel value is
determined from the input image at position
``cupy.dot(matrix, o) + offset``.
Args:
input (cupy.ndarray): The input array.
matrix (cupy.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.
- ``(ndim + 1, ndim + 1)``: assume that the transformation is
specified using homogeneous coordinates. 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): 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): Shape tuple.
output (cupy.ndarray or ~cupy.dtype): The array in which to place the
output, or the dtype of the returned array.
order (int): The order of the spline interpolation, default is 3. Must
be in the range 0-5.
mode (str): Points outside the boundaries of the input are filled
according to the given mode (``'constant'``, ``'nearest'``,
``'mirror'``, ``'reflect'``, ``'wrap'``, ``'grid-mirror'``,
``'grid-wrap'``, ``'grid-constant'`` or ``'opencv'``).
cval (scalar): Value used for points outside the boundaries of
the input if ``mode='constant'`` or ``mode='opencv'``. Default is
0.0
prefilter (bool): It is not used yet. It just exists for compatibility
with :mod:`scipy.ndimage`.
texture_memory (bool): If True, uses GPU texture memory. Supports only:
- 2D and 3D float32 arrays as input
- ``(ndim + 1, ndim + 1)`` homogeneous float32 transformation
matrix
- ``mode='constant'`` and ``mode='nearest'``
- ``order=0`` (nearest neighbor) and ``order=1`` (linear
interpolation)
- NVIDIA CUDA GPUs
Returns:
cupy.ndarray or None:
The transformed input. If ``output`` is given as a parameter,
``None`` is returned.
.. seealso:: :func:`scipy.ndimage.affine_transform`
"""
if texture_memory:
if runtime.is_hip:
raise RuntimeError(
'HIP currently does not support texture acceleration')
tm_interp = 'linear' if order > 0 else 'nearest'
return _texture.affine_transformation(data=input,
transformation_matrix=matrix,
output_shape=output_shape,
output=output,
interpolation=tm_interp,
mode=mode,
border_value=cval)
_check_parameter('affine_transform', order, mode)
offset = _util._fix_sequence_arg(offset, input.ndim, 'offset', float)
if matrix.ndim not in [1, 2] or matrix.shape[0] < 1:
raise RuntimeError('no proper affine matrix provided')
if matrix.ndim == 2:
if matrix.shape[0] == matrix.shape[1] - 1:
offset = matrix[:, -1]
matrix = matrix[:, :-1]
elif matrix.shape[0] == input.ndim + 1:
offset = matrix[:-1, -1]
matrix = matrix[:-1, :-1]
if matrix.shape != (input.ndim, input.ndim):
raise RuntimeError('improper affine shape')
if mode == 'opencv':
m = cupy.zeros((input.ndim + 1, input.ndim + 1))
m[:-1, :-1] = matrix
m[:-1, -1] = offset
m[-1, -1] = 1
m = cupy.linalg.inv(m)
m[:2] = cupy.roll(m[:2], 1, axis=0)
m[:2, :2] = cupy.roll(m[:2, :2], 1, axis=1)
matrix = m[:-1, :-1]
offset = m[:-1, -1]
if output_shape is None:
output_shape = input.shape
if mode == 'opencv' or mode == '_opencv_edge':
if matrix.ndim == 1:
matrix = cupy.diag(matrix)
coordinates = cupy.indices(output_shape, dtype=cupy.float64)
coordinates = cupy.dot(matrix, coordinates.reshape((input.ndim, -1)))
coordinates += cupy.expand_dims(cupy.asarray(offset), -1)
ret = _util._get_output(output, input, shape=output_shape)
ret[:] = map_coordinates(input, coordinates, ret.dtype, order, mode,
cval, prefilter).reshape(output_shape)
return ret
matrix = matrix.astype(cupy.float64, copy=False)
ndim = input.ndim
output = _util._get_output(output, input, shape=output_shape)
if input.dtype.kind in 'iu':
input = input.astype(cupy.float32)
filtered, nprepad = _filter_input(input, prefilter, mode, cval, order)
integer_output = output.dtype.kind in 'iu'
_util._check_cval(mode, cval, integer_output)
large_int = max(_prod(input.shape), _prod(output_shape)) > 1 << 31
if matrix.ndim == 1:
offset = cupy.asarray(offset, dtype=cupy.float64)
offset = -offset / matrix
kern = _interp_kernels._get_zoom_shift_kernel(
ndim,
large_int,
output_shape,
mode,
cval=cval,
order=order,
integer_output=integer_output,
nprepad=nprepad)
kern(filtered, offset, matrix, output)
else:
kern = _interp_kernels._get_affine_kernel(
ndim,
large_int,
output_shape,
mode,
cval=cval,
order=order,
integer_output=integer_output,
nprepad=nprepad)
m = cupy.zeros((ndim, ndim + 1), dtype=cupy.float64)
m[:, :-1] = matrix
m[:, -1] = cupy.asarray(offset, dtype=cupy.float64)
kern(filtered, m, output)
return output
