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Remove deprecated homography function

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Johannes Schönberger
2013-02-26 12:22:13 +01:00
parent c2023e9975
commit 72e1d20a29
1 changed files with 0 additions and 95 deletions
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skimage/transform/_warps.py
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@@ -253,98 +253,3 @@ def swirl(image, center=None, strength=1, radius=100, rotation=0,
return warp(image, _swirl_mapping, map_args=warp_args,
output_shape=output_shape,
order=order, mode=mode, cval=cval)
def homography(image, H, output_shape=None, order=1,
mode='constant', cval=0.):
"""
.. note:: Deprecated in skimage 0.7
`homography` will be removed in skimage 0.8, it is replaced by
`warp` because the latter provides the same functionality::
warp(image, ProjectiveTransform(H))
Perform a projective transformation (homography) on an image.
For each pixel, given its homogeneous coordinate :math:`\mathbf{x}
= [x, y, 1]^T`, its target position is calculated by multiplying
with the given matrix, :math:`H`, to give :math:`H \mathbf{x}`.
E.g., to rotate by theta degrees clockwise, the matrix should be
::
[[cos(theta) -sin(theta) 0]
[sin(theta) cos(theta) 0]
[0 0 1]]
or, to translate x by 10 and y by 20,
::
[[1 0 10]
[0 1 20]
[0 0 1 ]].
Parameters
----------
image : 2-D array
Input image.
H : array of shape ``(3, 3)``
Transformation matrix H that defines the homography.
output_shape : tuple (rows, cols)
Shape of the output image generated.
order : int
Order of splines used in interpolation.
mode : string
How to handle values outside the image borders. Passed as-is
to ndimage.
cval : string
Used in conjunction with mode 'constant', the value outside
the image boundaries.
Examples
--------
>>> # rotate by 90 degrees around origin and shift down by 2
>>> x = np.arange(9, dtype=np.uint8).reshape((3, 3)) + 1
>>> x
array([[1, 2, 3],
[4, 5, 6],
[7, 8, 9]], dtype=uint8)
>>> theta = -np.pi/2
>>> M = np.array([[np.cos(theta),-np.sin(theta),0],
... [np.sin(theta), np.cos(theta),2],
... [0, 0, 1]])
>>> x90 = homography(x, M, order=1)
>>> x90
array([[3, 6, 9],
[2, 5, 8],
[1, 4, 7]], dtype=uint8)
>>> # translate right by 2 and down by 1
>>> y = np.zeros((5,5), dtype=np.uint8)
>>> y[1, 1] = 255
>>> y
array([[ 0, 0, 0, 0, 0],
[ 0, 255, 0, 0, 0],
[ 0, 0, 0, 0, 0],
[ 0, 0, 0, 0, 0],
[ 0, 0, 0, 0, 0]], dtype=uint8)
>>> M = np.array([[ 1., 0., 2.],
... [ 0., 1., 1.],
... [ 0., 0., 1.]])
>>> y21 = homography(y, M, order=1)
>>> y21
array([[ 0, 0, 0, 0, 0],
[ 0, 0, 0, 0, 0],
[ 0, 0, 0, 255, 0],
[ 0, 0, 0, 0, 0],
[ 0, 0, 0, 0, 0]], dtype=uint8)
"""
import warnings
warnings.warn('the homography function is deprecated; '
'use the `warp` and `ProjectiveTransform` class instead',
category=DeprecationWarning)
tform = ProjectiveTransform(H)
return warp(image, inverse_map=tform.inverse, output_shape=output_shape,
order=order, mode=mode, cval=cval)