"""
=========================
Measure region properties
=========================

This example shows how to measure properties of labelled image regions.
"""

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

from skimage.util import img_as_ubyte
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)
props = regionprops(label_img, [
    'BoundingBox',
    'Centroid',
    'Orientation',
    'MajorAxisLength',
    'MinorAxisLength'
])

plt.imshow(image)

for prop in props:
    x0 = prop['Centroid'][1]
    y0 = prop['Centroid'][0]
    x1 = x0 + math.cos(prop['Orientation']) * 0.5 * prop['MajorAxisLength']
    y1 = y0 - math.sin(prop['Orientation']) * 0.5 * prop['MajorAxisLength']
    x2 = x0 - math.sin(prop['Orientation']) * 0.5 * prop['MinorAxisLength']
    y2 = y0 - math.cos(prop['Orientation']) * 0.5 * prop['MinorAxisLength']

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

    minr, minc, maxr, maxc = prop['BoundingBox']
    bx = (minc, maxc, maxc, minc, minc)
    by = (minr, minr, maxr, maxr, minr)
    plt.plot(bx, by, '-b', linewidth=2.5)

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