-
Notifications
You must be signed in to change notification settings - Fork 7
Expand file tree
/
Copy pathfeatures.html
More file actions
913 lines (630 loc) · 32.4 KB
/
Copy pathfeatures.html
File metadata and controls
913 lines (630 loc) · 32.4 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
<!DOCTYPE html>
<html lang="en" data-content_root="./" data-theme="auto">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="viewport" content="width=device-width, initial-scale=1" />
<meta property="og:title" content="Feature Extraction and Matching" />
<meta property="og:type" content="website" />
<meta property="og:url" content="https://colmap.github.io/features.html" />
<meta property="og:site_name" content="COLMAP" />
<meta property="og:description" content="COLMAP supports multiple feature extraction and matching algorithms. This page describes how to switch between them using the command-line interface or the graphical user interface. Feature Extract..." />
<meta property="og:image" content="https://colmap.github.io/_static/og-image.png" />
<meta property="og:image:alt" content="COLMAP — Structure-from-Motion & Multi-View Stereo" />
<meta name="description" content="COLMAP supports multiple feature extraction and matching algorithms. This page describes how to switch between them using the command-line interface or the graphical user interface. Feature Extract..." />
<meta name="twitter:card" content="summary_large_image" />
<title>Feature Extraction and Matching — COLMAP</title>
<script data-cfasync="false">
document.documentElement.dataset.mode = localStorage.getItem("mode") || "auto";
document.documentElement.dataset.theme = localStorage.getItem("theme") || "auto";
</script>
<!--
this give us a css class that will be invisible only if js is disabled
-->
<noscript>
<style>
.pst-js-only { display: none !important; }
</style>
</noscript>
<!-- Loaded before other Sphinx assets -->
<link href="_static/styles/theme.css?digest=90905a2f556bf617f1a9" rel="stylesheet" />
<link href="_static/styles/pydata-sphinx-theme.css?digest=90905a2f556bf617f1a9" rel="stylesheet" />
<link rel="stylesheet" type="text/css" href="_static/pygments.css?v=03e43079" />
<link rel="stylesheet" type="text/css" href="_static/sphinx-design.min.css?v=95c83b7e" />
<link rel="stylesheet" type="text/css" href="_static/custom.css?v=f70ce231" />
<link rel="stylesheet" type="text/css" href="_static/landing.css?v=1fe38c8d" />
<!-- So that users can add custom icons -->
<script defer src="_static/scripts/fontawesome.js?digest=90905a2f556bf617f1a9"></script>
<!-- Pre-loaded scripts that we'll load fully later -->
<link rel="preload" as="script" href="_static/scripts/bootstrap.js?digest=90905a2f556bf617f1a9" />
<link rel="preload" as="script" href="_static/scripts/pydata-sphinx-theme.js?digest=90905a2f556bf617f1a9" />
<script src="_static/documentation_options.js?v=49d32299"></script>
<script src="_static/doctools.js?v=fd6eb6e6"></script>
<script src="_static/sphinx_highlight.js?v=6ffebe34"></script>
<script src="_static/design-tabs.js?v=f930bc37"></script>
<script>DOCUMENTATION_OPTIONS.pagename = 'features';</script>
<script>DOCUMENTATION_OPTIONS.search_as_you_type = false;</script>
<script src="_static/install_selector.js?v=94a4b0a5"></script>
<script src="_static/external_links.js?v=cd4e6f29"></script>
<link rel="canonical" href="https://colmap.github.io/features.html" />
<link rel="icon" href="_static/favicon.svg"/>
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
<link rel="next" title="Database Format" href="database.html" />
<link rel="prev" title="3D Viewer" href="viewer.html" />
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<meta name="docsearch:language" content="en"/>
<meta name="docsearch:version" content="4.2.0.dev0 | 7f66f79 (2026-07-22)" />
<script src="_static/searchtools.js"></script>
<script src="_static/language_data.js"></script>
<script src="searchindex.js"></script>
</head>
<body data-default-mode="auto">
<div id="pst-skip-link" class="skip-link d-print-none"><a href="#main-content">Skip to main content</a></div>
<div id="pst-scroll-pixel-helper"></div>
<button type="button" class="btn rounded-pill" id="pst-back-to-top">
<i class="fa-solid fa-arrow-up"></i>Back to top</button>
<dialog id="pst-search-dialog">
<form class="bd-search d-flex align-items-center"
action="search.html"
method="get">
<i class="fa-solid fa-magnifying-glass"></i>
<input type="search"
class="form-control"
name="q"
placeholder="Search the docs ..."
aria-label="Search the docs ..."
autocomplete="off"
autocorrect="off"
autocapitalize="off"
spellcheck="false"/>
<span class="search-button__kbd-shortcut"><kbd class="kbd-shortcut__modifier">Ctrl</kbd>+<kbd>K</kbd></span>
</form>
</dialog>
<div class="pst-async-banner-revealer d-none">
<aside id="bd-header-version-warning" class="d-none d-print-none" aria-label="Version warning"></aside>
</div>
<header id="pst-header" class="bd-header navbar navbar-expand-lg bd-navbar d-print-none">
<div class="bd-header__inner bd-page-width">
<button class="pst-navbar-icon sidebar-toggle primary-toggle" aria-label="Site navigation">
<span class="fa-solid fa-bars"></span>
</button>
<div class=" navbar-header-items__start">
<div class="navbar-item">
<a class="navbar-brand logo" href="index.html">
<img src="_static/colmap-logo.svg" class="logo__image only-light" alt=""/>
<img src="_static/colmap-logo-dark.svg" class="logo__image only-dark pst-js-only" alt=""/>
<p class="title logo__title">COLMAP</p>
</a></div>
</div>
<div class=" navbar-header-items">
<div class="me-auto navbar-header-items__center">
<div class="navbar-item">
<nav>
<ul class="bd-navbar-elements navbar-nav">
<li class="nav-item ">
<a class="nav-link nav-internal" href="install.html">
Installation
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="tutorial.html">
Tutorial
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="concepts.html">
Key Concepts
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="viewer.html">
3D Viewer
</a>
</li>
<li class="nav-item dropdown">
<button class="btn dropdown-toggle nav-item" type="button"
data-bs-toggle="dropdown" aria-expanded="false"
aria-controls="pst-nav-more-links">
More
</button>
<ul id="pst-nav-more-links" class="dropdown-menu">
<li class=" current active">
<a class="nav-link dropdown-item nav-internal" href="#">
Feature Extraction and Matching
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="database.html">
Database Format
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="cameras.html">
Camera Models
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="rigs.html">
Rig Support
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="format.html">
Output Format
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="datasets.html">
Datasets
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="gui.html">
Graphical User Interface
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="cli.html">
Command-line Interface
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="pycolmap/index.html">
PyCOLMAP
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="faq.html">
Frequently Asked Questions
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="changelog.html">
Changelog
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="contribution.html">
Contribution
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="license.html">
License
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="bibliography.html">
Bibliography
</a>
</li>
<li class=" ">
<a class="nav-link dropdown-item nav-internal" href="legacy.html">
Legacy Documentations
</a>
</li>
</ul>
</li>
</ul>
</nav></div>
</div>
<div class="navbar-header-items__end">
<div class="navbar-item navbar-persistent--container">
<button class="btn search-button-field search-button__button pst-js-only" title="Search" aria-label="Search" data-bs-placement="bottom" data-bs-toggle="tooltip">
<i class="fa-solid fa-magnifying-glass"></i>
<span class="search-button__default-text">Search</span>
<span class="search-button__kbd-shortcut"><kbd class="kbd-shortcut__modifier">Ctrl</kbd>+<kbd class="kbd-shortcut__modifier">K</kbd></span>
</button>
</div>
<div class="navbar-item">
<div class="theme-switch-container dropdown pst-js-only" data-bs-toggle="tooltip" data-bs-placement="bottom" title="Color mode">
<button class="btn btn-sm nav-link pst-navbar-icon theme-switch-button dropdown-toggle" aria-label="Color mode" data-bs-toggle="dropdown">
<i class="theme-switch fa-solid fa-sun fa-lg fa-fw" data-mode="light" title="Light"></i>
<i class="theme-switch fa-solid fa-moon fa-lg fa-fw" data-mode="dark" title="Dark"></i>
<i class="theme-switch fa-solid fa-circle-half-stroke fa-lg fa-fw" data-mode="auto" title="System Settings"></i>
</button>
<ul class="dropdown-menu dropdown-menu-end">
<li><button class="dropdown-item d-flex align-items-center theme-change-button" data-mode="auto"><i class="fa-solid fa-circle-half-stroke fa-lg fa-fw me-1"></i>System Settings</button></li>
<li><button class="dropdown-item d-flex align-items-center theme-change-button" data-mode="light"><i class="fa-solid fa-sun fa-lg fa-fw me-1"></i>Light</button></li>
<li><button class="dropdown-item d-flex align-items-center theme-change-button" data-mode="dark"><i class="fa-solid fa-moon fa-lg fa-fw me-1"></i>Dark</button></li>
</ul>
</div></div>
<div class="navbar-item"><ul class="navbar-icon-links"
aria-label="Icon Links">
<li class="nav-item">
<a href="https://github.com/colmap/colmap" title="GitHub" class="nav-link pst-navbar-icon" rel="noopener" target="_blank" data-bs-toggle="tooltip" data-bs-placement="bottom"><i class="fa-brands fa-github fa-lg" aria-hidden="true"></i><span class="visually-hidden">GitHub</span></a>
</li>
<li class="nav-item">
<a href="https://pypi.org/project/pycolmap/" title="PyPI" class="nav-link pst-navbar-icon" rel="noopener" target="_blank" data-bs-toggle="tooltip" data-bs-placement="bottom"><i class="fa-brands fa-python fa-lg" aria-hidden="true"></i><span class="visually-hidden">PyPI</span></a>
</li>
<li class="nav-item">
<a href="https://hub.docker.com/r/colmap/colmap" title="Docker Hub" class="nav-link pst-navbar-icon" rel="noopener" target="_blank" data-bs-toggle="tooltip" data-bs-placement="bottom"><i class="fa-brands fa-docker fa-lg" aria-hidden="true"></i><span class="visually-hidden">Docker Hub</span></a>
</li>
</ul></div>
</div>
</div>
<div class="navbar-persistent--mobile">
<button class="btn search-button-field search-button__button pst-js-only" title="Search" aria-label="Search" data-bs-placement="bottom" data-bs-toggle="tooltip">
<i class="fa-solid fa-magnifying-glass"></i>
<span class="search-button__default-text">Search</span>
<span class="search-button__kbd-shortcut"><kbd class="kbd-shortcut__modifier">Ctrl</kbd>+<kbd class="kbd-shortcut__modifier">K</kbd></span>
</button>
</div>
<button class="pst-navbar-icon sidebar-toggle secondary-toggle" aria-label="On this page">
<span class="fa-solid fa-outdent"></span>
</button>
</div>
</header>
<div class="bd-container">
<div class="bd-container__inner bd-page-width">
<dialog id="pst-primary-sidebar-modal"></dialog>
<div id="pst-primary-sidebar" class="bd-sidebar-primary bd-sidebar">
<div class="sidebar-header-items sidebar-primary__section">
<div class="sidebar-header-items__center">
<div class="navbar-item">
<nav>
<ul class="bd-navbar-elements navbar-nav">
<li class="nav-item ">
<a class="nav-link nav-internal" href="install.html">
Installation
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="tutorial.html">
Tutorial
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="concepts.html">
Key Concepts
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="viewer.html">
3D Viewer
</a>
</li>
<li class="nav-item current active">
<a class="nav-link nav-internal" href="#">
Feature Extraction and Matching
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="database.html">
Database Format
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="cameras.html">
Camera Models
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="rigs.html">
Rig Support
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="format.html">
Output Format
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="datasets.html">
Datasets
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="gui.html">
Graphical User Interface
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="cli.html">
Command-line Interface
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="pycolmap/index.html">
PyCOLMAP
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="faq.html">
Frequently Asked Questions
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="changelog.html">
Changelog
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="contribution.html">
Contribution
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="license.html">
License
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="bibliography.html">
Bibliography
</a>
</li>
<li class="nav-item ">
<a class="nav-link nav-internal" href="legacy.html">
Legacy Documentations
</a>
</li>
</ul>
</nav></div>
</div>
<div class="sidebar-header-items__end">
<div class="navbar-item">
<div class="theme-switch-container dropdown pst-js-only" data-bs-toggle="tooltip" data-bs-placement="bottom" title="Color mode">
<button class="btn btn-sm nav-link pst-navbar-icon theme-switch-button dropdown-toggle" aria-label="Color mode" data-bs-toggle="dropdown">
<i class="theme-switch fa-solid fa-sun fa-lg fa-fw" data-mode="light" title="Light"></i>
<i class="theme-switch fa-solid fa-moon fa-lg fa-fw" data-mode="dark" title="Dark"></i>
<i class="theme-switch fa-solid fa-circle-half-stroke fa-lg fa-fw" data-mode="auto" title="System Settings"></i>
</button>
<ul class="dropdown-menu dropdown-menu-end">
<li><button class="dropdown-item d-flex align-items-center theme-change-button" data-mode="auto"><i class="fa-solid fa-circle-half-stroke fa-lg fa-fw me-1"></i>System Settings</button></li>
<li><button class="dropdown-item d-flex align-items-center theme-change-button" data-mode="light"><i class="fa-solid fa-sun fa-lg fa-fw me-1"></i>Light</button></li>
<li><button class="dropdown-item d-flex align-items-center theme-change-button" data-mode="dark"><i class="fa-solid fa-moon fa-lg fa-fw me-1"></i>Dark</button></li>
</ul>
</div></div>
<div class="navbar-item"><ul class="navbar-icon-links"
aria-label="Icon Links">
<li class="nav-item">
<a href="https://github.com/colmap/colmap" title="GitHub" class="nav-link pst-navbar-icon" rel="noopener" target="_blank" data-bs-toggle="tooltip" data-bs-placement="bottom"><i class="fa-brands fa-github fa-lg" aria-hidden="true"></i><span class="visually-hidden">GitHub</span></a>
</li>
<li class="nav-item">
<a href="https://pypi.org/project/pycolmap/" title="PyPI" class="nav-link pst-navbar-icon" rel="noopener" target="_blank" data-bs-toggle="tooltip" data-bs-placement="bottom"><i class="fa-brands fa-python fa-lg" aria-hidden="true"></i><span class="visually-hidden">PyPI</span></a>
</li>
<li class="nav-item">
<a href="https://hub.docker.com/r/colmap/colmap" title="Docker Hub" class="nav-link pst-navbar-icon" rel="noopener" target="_blank" data-bs-toggle="tooltip" data-bs-placement="bottom"><i class="fa-brands fa-docker fa-lg" aria-hidden="true"></i><span class="visually-hidden">Docker Hub</span></a>
</li>
</ul></div>
</div>
</div>
<div class="sidebar-primary-items__start sidebar-primary__section">
<div class="sidebar-primary-item pst-sidebar-collapse"><button id="pst-collapse-sidebar-button" aria-expanded="true" aria-controls="pst-primary-sidebar">
<svg class="pst-icon" role="img" aria-hidden="true" focusable="false" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg">
<path fill="currentColor" d="M3 15.5C2.36232 15.5 1.74874 15.2564 1.28478 14.8189C0.820828 14.3815 0.541576 13.7832 0.504167 13.1467L0.5 13L0.5 3C0.499965 2.36232 0.743605 1.74874 1.18107 1.28478C1.61854 0.820828 2.21676 0.541576 2.85333 0.504167L3 0.5L13 0.5C13.6377 0.499965 14.2513 0.743605 14.7152 1.18107C15.1792 1.61854 15.4584 2.21676 15.4958 2.85333L15.5 3L15.5 13C15.5 13.6377 15.2564 14.2513 14.8189 14.7152C14.3815 15.1792 13.7832 15.4584 13.1467 15.4958L13 15.5L3 15.5ZM3 13.8333L10.5 13.8333L10.5 2.16667L3 2.16667C2.79589 2.16669 2.59889 2.24163 2.44636 2.37726C2.29383 2.5129 2.19638 2.69979 2.1725 2.9025L2.16667 3L2.16667 13C2.16669 13.2041 2.24163 13.4011 2.37726 13.5536C2.5129 13.7062 2.69979 13.8036 2.9025 13.8275L3 13.8333ZM6.65583 10.325L6.5775 10.2558L4.91083 8.58917C4.76735 8.44567 4.68116 8.25476 4.66843 8.05223C4.65569 7.84971 4.71729 7.6495 4.84167 7.48917L4.91083 7.41083L6.5775 5.74417C6.72747 5.59471 6.9287 5.50794 7.14032 5.50148C7.35194 5.49502 7.55809 5.56935 7.7169 5.70937C7.8757 5.8494 7.97525 6.04463 7.99533 6.25539C8.01541 6.46616 7.95451 6.67667 7.825 6.84417L7.75583 6.9225L6.67917 8L7.75583 9.0775C7.89931 9.22099 7.98551 9.41191 7.99824 9.61443C8.01097 9.81695 7.94938 10.0172 7.825 10.1775L7.75583 10.2558C7.61234 10.3993 7.42142 10.4855 7.2189 10.4982C7.01638 10.511 6.81617 10.4494 6.65583 10.325Z"/>
</svg>
<span class="pst-collapse-sidebar-label">Collapse Sidebar</span>
<span class="pst-expand-sidebar-label">Expand Sidebar</span>
</button></div>
<div class="sidebar-primary-item">
<nav class="bd-docs-nav bd-links"
aria-label="Section Navigation">
<p class="bd-links__title" role="heading" aria-level="1">Section Navigation</p>
<div class="bd-toc-item navbar-nav"></div>
</nav></div>
</div>
<div class="sidebar-primary-items__end sidebar-primary__section">
<div class="sidebar-primary-item">
<div id="ethical-ad-placement"
class="flat"
data-ea-publisher="readthedocs"
data-ea-type="readthedocs-sidebar"
data-ea-manual="true">
</div></div>
</div>
</div>
<main id="main-content" class="bd-main" role="main">
<div class="bd-content">
<div class="bd-article-container">
<div class="bd-header-article d-print-none">
<div class="header-article-items header-article__inner">
<div class="header-article-items__start">
<div class="header-article-item">
<nav aria-label="Breadcrumb" class="d-print-none">
<ul class="bd-breadcrumbs">
<li class="breadcrumb-item breadcrumb-home">
<a href="index.html" class="nav-link" aria-label="Home">
<i class="fa-solid fa-home"></i>
</a>
</li>
<li class="breadcrumb-item active" aria-current="page"><span class="ellipsis">Feature Extraction and Matching</span></li>
</ul>
</nav>
</div>
</div>
</div>
</div>
<div id="searchbox"></div>
<article class="bd-article">
<section id="feature-extraction-and-matching">
<span id="features"></span><h1>Feature Extraction and Matching<a class="headerlink" href="#feature-extraction-and-matching" title="Link to this heading">#</a></h1>
<p>COLMAP supports multiple feature extraction and matching algorithms. This page
describes how to switch between them using the command-line interface or the
graphical user interface.</p>
<section id="feature-extractor-types">
<h2>Feature Extractor Types<a class="headerlink" href="#feature-extractor-types" title="Link to this heading">#</a></h2>
<p>The following feature extractor types are available:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">SIFT</span></code>: Scale-Invariant Feature Transform (default). The classic and most
widely tested feature extractor. Produces 128-dimensional uint8 descriptors.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">ALIKED</span></code>: A Lighter Keypoint and Descriptor Extractor. A learned feature
extractor that produces floating-point descriptors. Requires ONNX support to
be enabled at build time (<code class="docutils literal notranslate"><span class="pre">-DONNX_ENABLED=ON</span></code>).</p></li>
</ul>
<p>To select a feature extractor type via the command-line:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ colmap feature_extractor \
--database_path $DATASET_PATH/database.db \
--image_path $DATASET_PATH/images \
--FeatureExtraction.type ALIKED_N16ROT \
--AlikedExtraction.max_num_features 2048
</pre></div>
</div>
<p>For SIFT (the default), you can omit the type or explicitly set it:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ colmap feature_extractor \
--database_path $DATASET_PATH/database.db \
--image_path $DATASET_PATH/images \
--FeatureExtraction.type SIFT \
--SiftExtraction.max_num_features 8192
</pre></div>
</div>
<p>In the GUI, open <code class="docutils literal notranslate"><span class="pre">Processing</span> <span class="pre">></span> <span class="pre">Feature</span> <span class="pre">extraction</span></code> and select the desired
tab (SIFT, ALIKED, etc.) before clicking Extract.</p>
</section>
<section id="feature-matcher-types">
<h2>Feature Matcher Types<a class="headerlink" href="#feature-matcher-types" title="Link to this heading">#</a></h2>
<p>The following feature matcher types are available:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">SIFT_BRUTEFORCE</span></code>: Brute-force matching optimized for SIFT descriptors
(default). Uses L2 distance with ratio test.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">ALIKED_BRUTEFORCE</span></code>: Brute-force matching for ALIKED descriptors. Uses
cosine similarity. Requires ONNX support to be enabled at build time.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">SIFT_LIGHTGLUE</span></code>: Neural network-based matching using the LightGlue model
for SIFT descriptors. This typically produces more matches and higher inlier
ratios than brute-force matching, especially for challenging image pairs with
large viewpoint or illumination changes. Requires ONNX support to be enabled
at build time.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">ALIKED_LIGHTGLUE</span></code>: Neural network-based matching using the LightGlue model
for ALIKED descriptors. Requires ONNX support to be enabled at build time.</p></li>
</ul>
<p>To select a feature matcher type via the command-line:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ colmap exhaustive_matcher \
--database_path $DATASET_PATH/database.db \
--FeatureMatching.type ALIKED_BRUTEFORCE \
--AlikedMatching.min_cossim 0.85
</pre></div>
</div>
<p>For SIFT matching (the default):</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ colmap exhaustive_matcher \
--database_path $DATASET_PATH/database.db \
--FeatureMatching.type SIFT_BRUTEFORCE \
--SiftMatching.max_ratio 0.8
</pre></div>
</div>
<p>In the GUI, open <code class="docutils literal notranslate"><span class="pre">Processing</span> <span class="pre">></span> <span class="pre">Feature</span> <span class="pre">matching</span></code>, select any matching tab
(Exhaustive, Sequential, etc.), and choose the matcher type from the “Type”
dropdown in the shared options section.</p>
</section>
<section id="compatible-extractor-and-matcher-types">
<h2>Compatible Extractor and Matcher Types<a class="headerlink" href="#compatible-extractor-and-matcher-types" title="Link to this heading">#</a></h2>
<p>The feature extractor and matcher types should be compatible:</p>
<ul class="simple">
<li><p>Use <code class="docutils literal notranslate"><span class="pre">SIFT</span></code> extraction with <code class="docutils literal notranslate"><span class="pre">SIFT_BRUTEFORCE</span></code> or <code class="docutils literal notranslate"><span class="pre">SIFT_LIGHTGLUE</span></code> matching.</p></li>
<li><p>Use <code class="docutils literal notranslate"><span class="pre">ALIKED_*</span></code> extraction with <code class="docutils literal notranslate"><span class="pre">ALIKED_BRUTEFORCE</span></code> or <code class="docutils literal notranslate"><span class="pre">ALIKED_LIGHTGLUE</span></code> matching.</p></li>
</ul>
<p>Mixing incompatible types (e.g., SIFT features with ALIKED matcher) will
result in a runtime error. Do not mix different feature extractor types
(e.g., SIFT and ALIKED) in the same database.</p>
</section>
<section id="aliked-model-variants">
<h2>ALIKED Model Variants<a class="headerlink" href="#aliked-model-variants" title="Link to this heading">#</a></h2>
<p>ALIKED requires an ONNX model file. Several model variants are available with
different trade-offs between speed and accuracy:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">aliked-n16rot</span></code>: Faster and trained for some viewpoint invariance. 128-dim descriptors.</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">aliked-n32</span></code>: More expensive but not explicitly trained for viewpoint invariance, 128-dim descriptors.</p></li>
</ul>
<p>Specify the model path using <code class="docutils literal notranslate"><span class="pre">--AlikedExtraction.*_model_path</span></code>. If the path is
a URL, COLMAP will automatically download and cache the model. You can download
different ALIKED models from the release page at <a class="github reference external" href="https://github.com/colmap/colmap/releases/">colmap/colmap</a></p>
</section>
<section id="iterative-runs">
<h2>Iterative Runs<a class="headerlink" href="#iterative-runs" title="Link to this heading">#</a></h2>
<p>When re-running matching on an existing database, image pairs that already have
a two-view geometry are skipped, so changing <code class="docutils literal notranslate"><span class="pre">--FeatureMatching.type</span></code> on such
a database leaves previously matched pairs untouched. To force re-matching, first
clear the existing results with <code class="docutils literal notranslate"><span class="pre">database_cleaner</span></code>:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$ colmap database_cleaner \
--database_path $DATASET_PATH/database.db \
--type two_view_geometries \
--type matches
</pre></div>
</div>
<p>When re-extracting with a different <code class="docutils literal notranslate"><span class="pre">--FeatureExtraction.type</span></code>, use
<code class="docutils literal notranslate"><span class="pre">--type</span> <span class="pre">features</span></code> to additionally clear the extracted keypoints and descriptors.</p>
</section>
</section>
</article>
<footer class="prev-next-footer d-print-none">
<div class="prev-next-area">
<a class="left-prev"
href="viewer.html"
title="previous page">
<i class="fa-solid fa-angle-left"></i>
<div class="prev-next-info">
<p class="prev-next-subtitle">previous</p>
<p class="prev-next-title">3D Viewer</p>
</div>
</a>
<a class="right-next"
href="database.html"
title="next page">
<div class="prev-next-info">
<p class="prev-next-subtitle">next</p>
<p class="prev-next-title">Database Format</p>
</div>
<i class="fa-solid fa-angle-right"></i>
</a>
</div>
</footer>
</div>
<dialog id="pst-secondary-sidebar-modal"></dialog>
<div id="pst-secondary-sidebar" class="bd-sidebar-secondary bd-toc"><div class="sidebar-secondary-items sidebar-secondary__inner">
<div class="sidebar-secondary-item">
<div
id="pst-page-navigation-heading-2"
class="page-toc tocsection onthispage">
<i class="fa-solid fa-list"></i> On this page
</div>
<nav id="pst-page-toc-nav" class="page-toc" aria-labelledby="pst-page-navigation-heading-2">
<ul class="pst-show_toc_level nav section-nav flex-column">
<li class="toc-h2 nav-item toc-entry"><a class="reference internal nav-link" href="#feature-extractor-types">Feature Extractor Types</a></li>
<li class="toc-h2 nav-item toc-entry"><a class="reference internal nav-link" href="#feature-matcher-types">Feature Matcher Types</a></li>
<li class="toc-h2 nav-item toc-entry"><a class="reference internal nav-link" href="#compatible-extractor-and-matcher-types">Compatible Extractor and Matcher Types</a></li>
<li class="toc-h2 nav-item toc-entry"><a class="reference internal nav-link" href="#aliked-model-variants">ALIKED Model Variants</a></li>
<li class="toc-h2 nav-item toc-entry"><a class="reference internal nav-link" href="#iterative-runs">Iterative Runs</a></li>
</ul>
</nav></div>
<div class="sidebar-secondary-item">
<div class="tocsection sourcelink">
<a href="_sources/features.rst.txt">
<i class="fa-solid fa-file-lines"></i> Show Source
</a>
</div>
</div>
</div></div>
</div>
<footer class="bd-footer-content">
</footer>
</main>
</div>
</div>
<!-- Scripts loaded after <body> so the DOM is not blocked -->
<script defer src="_static/scripts/bootstrap.js?digest=90905a2f556bf617f1a9"></script>
<script defer src="_static/scripts/pydata-sphinx-theme.js?digest=90905a2f556bf617f1a9"></script>
<footer class="bd-footer">
<div class="bd-footer__inner bd-page-width">
<div class="footer-items__start">
<div class="footer-item">
<p class="copyright">
© Copyright 2026, COLMAP Team.
<br/>
</p>
</div>
</div>
<div class="footer-items__center">
<div class="footer-item">
<p class="footer-version">COLMAP 4.2.0.dev0 | 7f66f79 (2026-07-22)</p></div>
</div>
<div class="footer-items__end">
<div class="footer-item">
<p class="theme-version">
<!-- # L10n: Setting the PST URL as an argument as this does not need to be localized -->
Built with the <a href="https://pydata-sphinx-theme.readthedocs.io/en/stable/index.html">PyData Sphinx Theme</a> 0.20.0.
</p></div>
</div>
</div>
</footer>
</body>
</html>