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scikit-image/skimage/segmentation/boundaries.py
T

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1.5 KiB
Python

import numpy as np
from ..morphology import dilation, square
from ..util import img_as_float
from ..color import gray2rgb
from .._shared.utils import deprecated
def find_boundaries(label_img):
"""Return bool array where boundaries between labeled regions are True."""
boundaries = np.zeros(label_img.shape, dtype=np.bool)
boundaries[1:, :] += label_img[1:, :] != label_img[:-1, :]
boundaries[:, 1:] += label_img[:, 1:] != label_img[:, :-1]
return boundaries
def mark_boundaries(image, label_img, color=(1, 1, 0), outline_color=None):
"""Return image with boundaries between labeled regions highlighted.
Parameters
----------
image : (M, N[, 3]) array
Grayscale or RGB image.
label_img : (M, N) array
Label array where regions are marked by different integer values.
color : length-3 sequence
RGB color of boundaries in the output image.
outline_color : length-3 sequence
RGB color surrounding boundaries in the output image. If None, no
outline is drawn.
"""
if image.ndim == 2:
image = gray2rgb(image)
image = img_as_float(image, force_copy=True)
boundaries = find_boundaries(label_img)
if outline_color is not None:
outer_boundaries = dilation(boundaries.astype(np.uint8), square(2))
image[outer_boundaries != 0, :] = np.array(outline_color)
image[boundaries, :] = np.array(color)
return image
@deprecated('mark_boundaries')
def visualize_boundaries(*args, **kwargs):
return mark_boundaries(*args, **kwargs)