ORB feature detector and binary descriptorΒΆ

This example demonstrates the ORB feature detection and binary description algorithm. It uses an oriented FAST detection method and the rotated BRIEF descriptors.

Unlike BRIEF, ORB is comparatively scale and rotation invariant while still employing the very efficient Hamming distance metric for matching. As such, it is preferred for real-time applications.

../../_images/sphx_glr_plot_orb_001.png

Out:

/home/travis/venv/lib/python3.7/site-packages/skimage/feature/orb.py:142: FutureWarning: Until the version 0.16, threshold_rel was set to 0.1 by default.Starting from version 0.16, the default value is set to None.Until version 0.18, a None value corresponds to a threshold value of 0.1.The default behavior will match skimage.feature.peak_local_max.
  keypoints = corner_peaks(fast_response, min_distance=1)

from skimage import data
from skimage import transform as tf
from skimage.feature import (match_descriptors, corner_harris,
                             corner_peaks, ORB, plot_matches)
from skimage.color import rgb2gray
import matplotlib.pyplot as plt


img1 = rgb2gray(data.astronaut())
img2 = tf.rotate(img1, 180)
tform = tf.AffineTransform(scale=(1.3, 1.1), rotation=0.5,
                           translation=(0, -200))
img3 = tf.warp(img1, tform)

descriptor_extractor = ORB(n_keypoints=200)

descriptor_extractor.detect_and_extract(img1)
keypoints1 = descriptor_extractor.keypoints
descriptors1 = descriptor_extractor.descriptors

descriptor_extractor.detect_and_extract(img2)
keypoints2 = descriptor_extractor.keypoints
descriptors2 = descriptor_extractor.descriptors

descriptor_extractor.detect_and_extract(img3)
keypoints3 = descriptor_extractor.keypoints
descriptors3 = descriptor_extractor.descriptors

matches12 = match_descriptors(descriptors1, descriptors2, cross_check=True)
matches13 = match_descriptors(descriptors1, descriptors3, cross_check=True)

fig, ax = plt.subplots(nrows=2, ncols=1)

plt.gray()

plot_matches(ax[0], img1, img2, keypoints1, keypoints2, matches12)
ax[0].axis('off')
ax[0].set_title("Original Image vs. Transformed Image")

plot_matches(ax[1], img1, img3, keypoints1, keypoints3, matches13)
ax[1].axis('off')
ax[1].set_title("Original Image vs. Transformed Image")


plt.show()

Total running time of the script: ( 0 minutes 1.820 seconds)

Gallery generated by Sphinx-Gallery