`skimage.draw.draw:circle_perimeter_aa`

source: /dev/scikit-image/src/skimage/draw/draw.py :585

Signature

def circle_perimeter_aa ( r , c , radius , shape = None )

Summary

Generate anti-aliased circle perimeter coordinates.

Parameters

r, c : int: Centre coordinate of circle.
radius : int: Radius of circle.
shape : tuple, optional: Image shape which is used to determine the maximum extent of output pixel coordinates. This is useful for circles that exceed the image size. If None, the full extent of the circle is used. Must be at least length 2. Only the first two values are used to determine the extent of the input image.

Returns

rr, cc, val : (N,) ndarray (int, int, float): Indices of pixels (rr, cc) and intensity values (val). img[rr, cc] = val.

Notes

Wu's method draws anti-aliased circle. This implementation doesn't use lookup table optimization.

Use the function draw.set_color to apply circle_perimeter_aa results to color images.

Examples

from skimage.draw import circle_perimeter_aa
img = np.zeros((10, 10), dtype=np.uint8)
rr, cc, val = circle_perimeter_aa(4, 4, 3)
img[rr, cc] = val * 255
img

✓

from skimage import data, draw
image = data.chelsea()
rr, cc, val = draw.circle_perimeter_aa(r=100, c=100, radius=75)
draw.set_color(image, (rr, cc), [1, 0, 0], alpha=val)

✓

Aliases

skimage.draw.circle_perimeter_aa