.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "auto_examples/features_detection/plot_sift.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. or to run this example in your browser via Binder .. rst-class:: sphx-glr-example-title .. _sphx_glr_auto_examples_features_detection_plot_sift.py: ============================================== SIFT feature detector and descriptor extractor ============================================== This example demonstrates the SIFT feature detection and its description algorithm. The scale-invariant feature transform (SIFT) [1]_ was published in 1999 and is still one of the most popular feature detectors available, as its promises to be "invariant to image scaling, translation, and rotation, and partially in-variant to illumination changes and affine or 3D projection" [2]_. Its biggest drawback is its runtime, that's said to be "at two orders of magnitude" [3]_ slower than ORB, which makes it unsuitable for real-time applications. References ---------- .. [1] https://en.wikipedia.org/wiki/Scale-invariant_feature_transform .. [2] D.G. Lowe. "Object recognition from local scale-invariant features", Proceedings of the Seventh IEEE International Conference on Computer Vision, 1999, vol.2, pp. 1150-1157. :DOI:`10.1109/ICCV.1999.790410` .. [3] Ethan Rublee, Vincent Rabaud, Kurt Konolige and Gary Bradski "ORB: An efficient alternative to SIFT and SURF" http://www.gwylab.com/download/ORB_2012.pdf .. GENERATED FROM PYTHON SOURCE LINES 30-95 .. image-sg:: /auto_examples/features_detection/images/sphx_glr_plot_sift_001.png :alt: Original Image vs. Flipped Image (all keypoints and matches), Original Image vs. Flipped Image (subset of matches for visibility), Original Image vs. Transformed Image (all keypoints and matches), Original Image vs. Transformed Image (subset of matches for visibility) :srcset: /auto_examples/features_detection/images/sphx_glr_plot_sift_001.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out .. code-block:: none /Users/cw/baidu/code/fin_tool/github/scikit-image/doc/examples/features_detection/plot_sift.py:67: FutureWarning: `plot_matches` is deprecated since version 0.23 and will be removed in version 0.25. Use `skimage.feature.plot_matched_features` instead. /Users/cw/baidu/code/fin_tool/github/scikit-image/doc/examples/features_detection/plot_sift.py:71: FutureWarning: `plot_matches` is deprecated since version 0.23 and will be removed in version 0.25. Use `skimage.feature.plot_matched_features` instead. /Users/cw/baidu/code/fin_tool/github/scikit-image/doc/examples/features_detection/plot_sift.py:77: FutureWarning: `plot_matches` is deprecated since version 0.23 and will be removed in version 0.25. Use `skimage.feature.plot_matched_features` instead. /Users/cw/baidu/code/fin_tool/github/scikit-image/doc/examples/features_detection/plot_sift.py:85: FutureWarning: `plot_matches` is deprecated since version 0.23 and will be removed in version 0.25. Use `skimage.feature.plot_matched_features` instead. | .. code-block:: Python import matplotlib.pyplot as plt from skimage import data from skimage import transform from skimage.color import rgb2gray from skimage.feature import match_descriptors, plot_matches, SIFT img1 = rgb2gray(data.astronaut()) img2 = transform.rotate(img1, 180) tform = transform.AffineTransform(scale=(1.3, 1.1), rotation=0.5, translation=(0, -200)) img3 = transform.warp(img1, tform) descriptor_extractor = SIFT() 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, max_ratio=0.6, cross_check=True ) matches13 = match_descriptors( descriptors1, descriptors3, max_ratio=0.6, cross_check=True ) fig, ax = plt.subplots(nrows=2, ncols=2, figsize=(11, 8)) plt.gray() plot_matches(ax[0, 0], img1, img2, keypoints1, keypoints2, matches12) ax[0, 0].axis('off') ax[0, 0].set_title("Original Image vs. Flipped Image\n" "(all keypoints and matches)") plot_matches(ax[1, 0], img1, img3, keypoints1, keypoints3, matches13) ax[1, 0].axis('off') ax[1, 0].set_title( "Original Image vs. Transformed Image\n" "(all keypoints and matches)" ) plot_matches( ax[0, 1], img1, img2, keypoints1, keypoints2, matches12[::15], only_matches=True ) ax[0, 1].axis('off') ax[0, 1].set_title( "Original Image vs. Flipped Image\n" "(subset of matches for visibility)" ) plot_matches( ax[1, 1], img1, img3, keypoints1, keypoints3, matches13[::15], only_matches=True ) ax[1, 1].axis('off') ax[1, 1].set_title( "Original Image vs. Transformed Image\n" "(subset of matches for visibility)" ) plt.tight_layout() plt.show() .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 2.198 seconds) .. _sphx_glr_download_auto_examples_features_detection_plot_sift.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: binder-badge .. image:: images/binder_badge_logo.svg :target: https://mybinder.org/v2/gh/scikit-image/scikit-image/v0.24.0?filepath=notebooks/auto_examples/features_detection/plot_sift.ipynb :alt: Launch binder :width: 150 px .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_sift.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_sift.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: plot_sift.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_