`skimage.measure.profile:profile_line`

source: /dev/scikit-image/src/skimage/measure/profile.py :7

Signature

   def     profile_line (    image    ,    src    ,    dst    ,    linewidth    =  1   ,    order    =  None   ,    mode    =  reflect   ,    cval    =  0.0   ,  * ,     reduce_func    =  <function mean at 0x0000>     )

Summary

Return the intensity profile of an image measured along a scan line.

Parameters

image : ndarray, shape (M, N[, C]): The image, either grayscale (2D array) or multichannel (3D array, where the final axis contains the channel information).
src : array_like, shape (2,): The coordinates of the start point of the scan line.
dst : array_like, shape (2,): The coordinates of the end point of the scan line. The destination point is included in the profile, in contrast to standard numpy indexing.
linewidth : int, optional: Width of the scan, perpendicular to the line
order : {0, 1, 2, 3, 4, 5}, optional: The order of the spline interpolation, default is 0 if image.dtype is bool and 1 otherwise. The order has to be in the range 0-5. See skimage.transform.warp for detail.
mode : {'constant', 'nearest', 'reflect', 'mirror', 'wrap'}, optional: How to compute any values falling outside of the image.
cval : float, optional: If mode is 'constant', what constant value to use outside the image.
reduce_func : callable, optional: Function used to calculate the aggregation of pixel values perpendicular to the profile_line direction when linewidth > 1. If set to None the unreduced array will be returned.

Returns

return_value : array: The intensity profile along the scan line. The length of the profile is the ceil of the computed length of the scan line.

Examples

x = np.array([[1, 1, 1, 2, 2, 2]])
img = np.vstack([np.zeros_like(x), x, x, x, np.zeros_like(x)])
img
profile_line(img, (2, 1), (2, 4))
profile_line(img, (1, 0), (1, 6), cval=4)

✓

The destination point is included in the profile, in contrast to standard numpy indexing. For example:

profile_line(img, (1, 0), (1, 6))  # The final point is out of bounds
profile_line(img, (1, 0), (1, 5))  # This accesses the full first row

✓

For different reduce_func inputs:

profile_line(img, (1, 0), (1, 3), linewidth=3, reduce_func=np.mean)
profile_line(img, (1, 0), (1, 3), linewidth=3, reduce_func=np.max)
profile_line(img, (1, 0), (1, 3), linewidth=3, reduce_func=np.sum)

✓

The unreduced array will be returned when `reduce_func` is None or when `reduce_func` acts on each pixel value individually.

profile_line(img, (1, 2), (4, 2), linewidth=3, order=0,
    reduce_func=None)
profile_line(img, (1, 0), (1, 3), linewidth=3, reduce_func=np.sqrt)

✓

Aliases

skimage.measure.profile_line