Measure region properties¶

import math
import matplotlib.pyplot as plt
import numpy as np

from skimage.draw import ellipse
from skimage.morphology import label
from skimage.measure import regionprops
from skimage.transform import rotate


image = np.zeros((600, 600))

rr, cc = ellipse(300, 350, 100, 220)
image[rr,cc] = 1

image = rotate(image, angle=15, order=0)

label_img = label(image)
regions = regionprops(label_img)

fig, ax = plt.subplots()
ax.imshow(image, cmap=plt.cm.gray)

for props in regions:
    y0, x0 = props.centroid
    orientation = props.orientation
    x1 = x0 + math.cos(orientation) * 0.5 * props.major_axis_length
    y1 = y0 - math.sin(orientation) * 0.5 * props.major_axis_length
    x2 = x0 - math.sin(orientation) * 0.5 * props.minor_axis_length
    y2 = y0 - math.cos(orientation) * 0.5 * props.minor_axis_length

    ax.plot((x0, x1), (y0, y1), '-r', linewidth=2.5)
    ax.plot((x0, x2), (y0, y2), '-r', linewidth=2.5)
    ax.plot(x0, y0, '.g', markersize=15)

    minr, minc, maxr, maxc = props.bbox
    bx = (minc, maxc, maxc, minc, minc)
    by = (minr, minr, maxr, maxr, minr)
    ax.plot(bx, by, '-b', linewidth=2.5)

ax.axis((0, 600, 600, 0))
plt.show()