diff --git a/skimage/transform/_warps.py b/skimage/transform/_warps.py index 5af3afa6..7ac3e63f 100644 --- a/skimage/transform/_warps.py +++ b/skimage/transform/_warps.py @@ -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)