-
Notifications
You must be signed in to change notification settings - Fork 0
/
about.html
569 lines (509 loc) · 35.3 KB
/
about.html
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
<!DOCTYPE html>
<html class="writer-html5" lang="ja" >
<head>
<meta charset="utf-8" /><meta name="generator" content="Docutils 0.17.1: http://docutils.sourceforge.net/" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>About — pdal.io</title>
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<link rel="stylesheet" href="_static/css/pdal.css" type="text/css" />
<link rel="stylesheet" href="_static/breathe.css" type="text/css" />
<link rel="shortcut icon" href="_static/favicon.ico"/>
<link rel="canonical" href="https://pdal.io/about.html"/>
<!--[if lt IE 9]>
<script src="_static/js/html5shiv.min.js"></script>
<![endif]-->
<script data-url_root="./" id="documentation_options" src="_static/documentation_options.js"></script>
<script src="_static/jquery.js"></script>
<script src="_static/underscore.js"></script>
<script src="_static/_sphinx_javascript_frameworks_compat.js"></script>
<script src="_static/doctools.js"></script>
<script src="_static/translations.js"></script>
<script src="_static/js/theme.js"></script>
<link rel="author" title="このドキュメントについて" href="#" />
<link rel="index" title="索引" href="genindex.html" />
<link rel="search" title="検索" href="search.html" />
<link rel="copyright" title="著作権" href="copyright.html" />
<link rel="next" title="Download" href="download.html" />
<link rel="prev" title="PDAL - Point Data Abstraction Library" href="index.html" />
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search" >
<a href="index.html" class="icon icon-home"> PDAL
</a>
<div class="version">
2.7.0
</div>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
<ul class="current">
<li class="toctree-l1 current"><a class="current reference internal" href="#">About</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#what-is-pdal">What is PDAL?</a></li>
<li class="toctree-l2"><a class="reference internal" href="#what-is-its-big-idea">What is its big idea?</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#why-would-you-want-to-do-that">Why would you want to do that?</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="#how-is-it-different-than-other-tools">How is it different than other tools?</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#lastools">LAStools</a></li>
<li class="toctree-l3"><a class="reference internal" href="#pcl">PCL</a></li>
<li class="toctree-l3"><a class="reference internal" href="#entwine">Entwine</a></li>
<li class="toctree-l3"><a class="reference internal" href="#untwine">Untwine</a></li>
<li class="toctree-l3"><a class="reference internal" href="#viewer-copc-io">viewer.copc.io</a></li>
<li class="toctree-l3"><a class="reference internal" href="#potree">Potree</a></li>
<li class="toctree-l3"><a class="reference internal" href="#others">Others</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="#where-did-pdal-come-from">Where did PDAL come from?</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#how-is-point-cloud-data-different-than-raster-or-vector-geo-data">How is point cloud data different than raster or vector geo data?</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="#what-tasks-are-pdal-good-at">What tasks are PDAL good at?</a></li>
<li class="toctree-l2"><a class="reference internal" href="#what-are-pdal-s-weak-points">What are PDAL's weak points?</a></li>
<li class="toctree-l2"><a class="reference internal" href="#high-level-overview">High Level Overview</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#core-c-software-library">Core C++ Software Library</a></li>
<li class="toctree-l3"><a class="reference internal" href="#command-line-utilities">Command Line Utilities</a></li>
<li class="toctree-l3"><a class="reference internal" href="#python-api">Python API</a></li>
<li class="toctree-l3"><a class="reference internal" href="#julia-plugin">Julia Plugin</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="#conclusion">Conclusion</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="download.html">Download</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="quickstart.html">Quickstart</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="apps/index.html">Applications</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="community.html">Community</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="pipeline.html">Pipeline</a></li>
<li class="toctree-l1"><a class="reference internal" href="stages/stages.html">Stages</a></li>
<li class="toctree-l1"><a class="reference internal" href="stages/readers.html">Readers</a></li>
<li class="toctree-l1"><a class="reference internal" href="stages/writers.html">Writers</a></li>
<li class="toctree-l1"><a class="reference internal" href="stages/filters.html">Filters</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="dimensions.html">Dimensions</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="types.html">Types</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="python.html">Python</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="java.html">Java</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="tutorial/index.html">Tutorials</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="workshop/index.html">Workshop</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="development/index.html">Development</a></li>
<li class="toctree-l1"><a class="reference internal" href="project/index.html">Project</a></li>
<li class="toctree-l1"><a class="reference internal" href="api/index.html">API</a></li>
<li class="toctree-l1"><a class="reference internal" href="faq.html">FAQ</a></li>
<li class="toctree-l1"><a class="reference internal" href="copyright.html">License</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="references.html">References</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap"><nav class="wy-nav-top" aria-label="Mobile navigation menu" >
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="index.html">PDAL</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="index.html"> Documentation </a> »</li>
<li>About</li>
<li class="wy-breadcrumbs-aside">
<a href="https://github.com/PDAL/PDAL/edit/master/doc/about.rst" class="fa fa-github"> Edit on GitHub</a>
</li>
</ul>
<div class="rst-breadcrumbs-buttons" role="navigation" aria-label="breadcrumb navigation">
<a href="download.html" class="btn btn-neutral float-right" title="Download" accesskey="n">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="index.html" class="btn btn-neutral float-left" title="PDAL - Point Data Abstraction Library" accesskey="p"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<section id="about">
<span id="id1"></span><h1>About<a class="headerlink" href="#about" title="Permalink to this heading"></a></h1>
<section id="what-is-pdal">
<h2>What is PDAL?<a class="headerlink" href="#what-is-pdal" title="Permalink to this heading"></a></h2>
<p><a class="reference external" href="https://pdal.io/">PDAL</a> is Point Data Abstraction Library. It is a C/C++ open source library
and applications for translating and processing <a class="reference external" href="https://en.wikipedia.org/wiki/Point_cloud">point cloud data</a>. It is not
limited to <a class="reference external" href="https://en.wikipedia.org/wiki/Lidar">LiDAR</a> data, although the focus and impetus for many of the
tools in the library have their origins in LiDAR.</p>
</section>
<section id="what-is-its-big-idea">
<h2>What is its big idea?<a class="headerlink" href="#what-is-its-big-idea" title="Permalink to this heading"></a></h2>
<p>PDAL allows you to compose <a class="reference internal" href="stages/filters.html#filters"><span class="std std-ref">operations</span></a> on point clouds into
<a class="reference internal" href="pipeline.html#pipeline"><span class="std std-ref">pipelines</span></a> of stages. These pipelines can
be written in a declarative JSON syntax or constructed using the available API.</p>
<section id="why-would-you-want-to-do-that">
<h3>Why would you want to do that?<a class="headerlink" href="#why-would-you-want-to-do-that" title="Permalink to this heading"></a></h3>
<p>A task might be to load some <a class="reference external" href="http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html">ASPRS LAS</a> (the most common LiDAR binary format)
data into a database, but you wanted to transform it into a common coordinate
system along the way.</p>
<p>One option would be to write a specialized monolithic
program that reads LAS data, reprojects it as necessary, and then handles the
necessary operations to insert the data in the appropriate format in the
database. This approach has a distinct disadvantage in that without careful
planning it could quickly spiral out of control as you add new little tweaks
and features to the operation. It ends up being very specific, and it
does not allow you to easily reuse the component that reads the LAS data
separately from the component that transforms the data.</p>
<p>The PDAL approach is to chain together a set of components,
each of which encapsulates specific functionality. The components allow for
reuse, composition, and separation of concerns. PDAL views point cloud
processing operations as a pipeline composed as a series of stages. You might
have a simple pipeline composed of a <a class="reference internal" href="stages/readers.las.html#readers-las"><span class="std std-ref">LAS Reader</span></a> stage, a
<a class="reference internal" href="stages/filters.reprojection.html#filters-reprojection"><span class="std std-ref">Reprojection</span></a> stage, and a <a class="reference internal" href="stages/writers.pgpointcloud.html#writers-pgpointcloud"><span class="std std-ref">PostgreSQL Writer</span></a>, for example. Rather than writing a single, monolithic
specialized program to perform this operation, you can dynamically compose it
as a sequence of steps or operations.</p>
<figure class="align-default" id="id7">
<img alt="_images/las-reproject-pgpointcloud.png" src="_images/las-reproject-pgpointcloud.png" />
<figcaption>
<p><span class="caption-text">A simple PDAL pipeline composed of a reader, filter, and writer
stages.</span><a class="headerlink" href="#id7" title="この画像へのパーマリンク"></a></p>
</figcaption>
</figure>
<p>A PDAL JSON <a class="reference internal" href="pipeline.html#pipeline"><span class="std std-ref">Pipeline</span></a> that composes this operation to reproject
and load the data into PostgreSQL might look something like the following:</p>
<div class="highlight-json notranslate"><div class="highlight"><pre><span></span><span class="linenos"> 1</span><span class="p">{</span>
<span class="linenos"> 2</span><span class="w"> </span><span class="nt">"pipeline"</span><span class="p">:[</span>
<span class="linenos"> 3</span><span class="w"> </span><span class="p">{</span>
<span class="hll"><span class="linenos"> 4</span><span class="w"> </span><span class="nt">"type"</span><span class="p">:</span><span class="s2">"readers.las"</span><span class="p">,</span>
</span><span class="linenos"> 5</span><span class="w"> </span><span class="nt">"filename"</span><span class="p">:</span><span class="s2">"input.las"</span>
<span class="linenos"> 6</span><span class="w"> </span><span class="p">},</span>
<span class="linenos"> 7</span><span class="w"> </span><span class="p">{</span>
<span class="hll"><span class="linenos"> 8</span><span class="w"> </span><span class="nt">"type"</span><span class="p">:</span><span class="s2">"filters.reprojection"</span><span class="p">,</span>
</span><span class="linenos"> 9</span><span class="w"> </span><span class="nt">"out_srs"</span><span class="p">:</span><span class="s2">"EPSG:3857"</span>
<span class="linenos">10</span><span class="w"> </span><span class="p">},</span>
<span class="linenos">11</span><span class="w"> </span><span class="p">{</span>
<span class="hll"><span class="linenos">12</span><span class="w"> </span><span class="nt">"type"</span><span class="p">:</span><span class="s2">"writers.pgpointcloud"</span><span class="p">,</span>
</span><span class="linenos">13</span><span class="w"> </span><span class="nt">"connection"</span><span class="p">:</span><span class="s2">"host='localhost' dbname='lidar' user='hobu'"</span><span class="p">,</span>
<span class="linenos">14</span><span class="w"> </span><span class="nt">"table"</span><span class="p">:</span><span class="s2">"output"</span><span class="p">,</span>
<span class="linenos">15</span><span class="w"> </span><span class="nt">"srid"</span><span class="p">:</span><span class="s2">"3857"</span>
<span class="linenos">16</span><span class="w"> </span><span class="p">}</span>
<span class="linenos">17</span><span class="w"> </span><span class="p">]</span>
<span class="linenos">18</span><span class="p">}</span>
</pre></div>
</div>
<p>PDAL can compose intermediate stages for operations such as filtering,
clipping, tiling, transforming into a processing pipeline and reuse as
necessary. It allows you to define these pipelines as <a class="reference external" href="https://en.wikipedia.org/wiki/JSON">JSON</a>, and it
provides a command, <a class="reference internal" href="apps/pipeline.html#pipeline-command"><span class="std std-ref">pipeline</span></a>, to allow you to execute them.</p>
<div class="admonition note">
<p class="admonition-title">注釈</p>
<p>Raster processing tools often compose operations with this approach.
PDAL conceptually steals its pipeline modeling from <a class="reference external" href="http://gdal.org/">GDAL</a>'s
<a class="reference external" href="http://www.gdal.org/gdal_vrttut.html">Virtual Raster Format</a>.</p>
</div>
</section>
</section>
<section id="how-is-it-different-than-other-tools">
<h2>How is it different than other tools?<a class="headerlink" href="#how-is-it-different-than-other-tools" title="Permalink to this heading"></a></h2>
<section id="lastools">
<h3>LAStools<a class="headerlink" href="#lastools" title="Permalink to this heading"></a></h3>
<p id="index-0">One of the most common open source processing tool suites available for LiDAR
processing is <a class="reference external" href="http://lastools.org">LAStools</a> from <a class="reference external" href="https://www.cs.unc.edu/~isenburg/">Martin Isenburg</a>. PDAL is different in
philosophy in a number of important ways:</p>
<ol class="arabic simple">
<li><p>All components of PDAL are released as open source software under an
<a class="reference external" href="https://opensource.org/licenses">OSI</a>-approved license.</p></li>
<li><p>PDAL allows application developers to provide proprietary extensions that
act as stages in processing pipelines. These might be things like custom
format readers, specialized exploitation algorithms, or entire processing
pipelines.</p></li>
<li><p>PDAL can operate on point cloud data of any format
-- not just <a class="reference external" href="http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html">ASPRS LAS</a>. <a class="reference external" href="http://lastools.org">LAStools</a> can read and write formats other than
LAS, but relates all data to its internal handling of LAS data, limiting
it to <a class="reference internal" href="dimensions.html#dimensions"><span class="std std-ref">dimension</span></a> types provided by the LAS format.</p></li>
<li><p>PDAL is coordinated by users with its declarative <a class="reference internal" href="pipeline.html#pipeline"><span class="std std-ref">JSON</span></a>
syntax. LAStools is coordinated by linking lots of small, specialized
command line utilities together with intricate arguments.</p></li>
<li><p>PDAL is an open source project, with all of its development activities
available online at <a class="reference external" href="https://github.com/PDAL/PDAL">https://github.com/PDAL/PDAL</a></p></li>
</ol>
</section>
<section id="pcl">
<span id="about-pcl"></span><h3>PCL<a class="headerlink" href="#pcl" title="Permalink to this heading"></a></h3>
<p id="index-1"><a class="reference external" href="http://pointclouds.org">PCL</a> is a complementary, rather than substitute, open source software
processing suite for point cloud data. The developer community of the PCL
library is focused on algorithm development, robotic and computer vision, and
real-time laser scanner processing. PDAL can read and write PCL's PCD format.</p>
</section>
<section id="entwine">
<h3>Entwine<a class="headerlink" href="#entwine" title="Permalink to this heading"></a></h3>
<p id="index-2"><a class="reference external" href="https://entwine.io">Entwine</a> is open source software from Hobu, Inc. that organizes massive point
cloud collections into streamable data services. These two software projects
allow province-scale LiDAR collections to be organized and served via HTTP
clients over the internet. PDAL provides <a class="reference internal" href="stages/readers.ept.html#readers-ept"><span class="std std-ref">readers.ept</span></a> to allow users to
read data from those <a class="reference external" href="https://entwine.io/entwine-point-tile.html">Entwine Point Tile</a> collections that Entwine produces..</p>
</section>
<section id="untwine">
<h3>Untwine<a class="headerlink" href="#untwine" title="Permalink to this heading"></a></h3>
<p><a class="reference external" href="https://github.com/hobuinc/untwine">Untwine</a> is open source software from Hobu, Inc. that organizes massive point
just like Entwine, but it does so in a bottom-up rather than top-down way.</p>
</section>
<section id="viewer-copc-io">
<span id="index-3"></span><h3>viewer.copc.io<a class="headerlink" href="#viewer-copc-io" title="Permalink to this heading"></a></h3>
<p>The Eptium viewer from Hobu, Inc. is a commercial lidar exploitation and
visualization platform based on Cesium that can be used to visualize <a class="reference external" href="https://copc.io">COPC</a>
and <a class="reference external" href="https://entwine.io/entwine-point-tile.html">Entwine Point Tile</a> content.</p>
</section>
<section id="potree">
<h3>Potree<a class="headerlink" href="#potree" title="Permalink to this heading"></a></h3>
<p><a class="reference external" href="http://potree.org">Potree</a> is a <a class="reference external" href="https://en.wikipedia.org/wiki/WebGL">WebGL</a> HTML5 point cloud renderer that speaks <a class="reference external" href="http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html">ASPRS LAS</a> and
<a class="reference external" href="http://laszip.org">LASzip</a> compressed LAS. You can find the software at
<a class="reference external" href="https://github.com/potree/potree/">https://github.com/potree/potree/</a></p>
<div class="admonition note">
<p class="admonition-title">注釈</p>
<p>See Potree in action using the USGS 3DEP AWS Public Dataset at
<a class="reference external" href="https://usgs.entwine.io">https://usgs.entwine.io</a></p>
</div>
</section>
<section id="others">
<h3>Others<a class="headerlink" href="#others" title="Permalink to this heading"></a></h3>
<p id="index-4">Other open source point cloud softwares tend to be Desktop GUI, rather than
library, focused. They include some processing operations, and sometimes they
even embed tools such as PDAL. We're obviously biased toward PDAL, but you
might find useful bits of functionality in them. These other tools include:</p>
<ul class="simple">
<li><p><a class="reference external" href="http://liblas.org">libLAS</a></p></li>
<li><p><a class="reference external" href="http://www.danielgm.net/cc/">CloudCompare</a></p></li>
<li><p><a class="reference external" href="http://www.idaholidar.org/tools/fusion-ldv/">Fusion</a></p></li>
<li><p><a class="reference external" href="https://www.orfeo-toolbox.org/">OrfeoToolbox</a></p></li>
</ul>
<div class="admonition note">
<p class="admonition-title">注釈</p>
<p>The <a class="reference external" href="http://liblas.org">libLAS</a> project is an open source project that predates PDAL, and
provides some of the processing capabilities provided by PDAL. It is
currently in maintenance mode due to its dependence on LAS, the release of
relevant LAStools capabilities as open source, and the completion of
<a class="reference external" href="https://pypi.python.org/pypi/laspy/1.4.1">Python LAS</a> software.</p>
</div>
</section>
</section>
<section id="where-did-pdal-come-from">
<h2>Where did PDAL come from?<a class="headerlink" href="#where-did-pdal-come-from" title="Permalink to this heading"></a></h2>
<p>PDAL takes its cue from another very popular open source project -- <a class="reference external" href="http://gdal.org/">GDAL</a>.
GDAL is Geospatial Data Abstraction Library, and it is used throughout the
geospatial software industry to provide translation and processing support for
a variety of raster and vector formats. PDAL provides the same capability for
point cloud data types.</p>
<p>PDAL evolved out of the development of database storage and access capabilities
for the U.S. Army Corps of Engineers <a class="reference external" href="http://www.erdc.usace.army.mil/Media/Fact-Sheets/Fact-Sheet-Article-View/Article/476649/remote-sensinggeographic-information-systems-center/">CRREL</a> <a class="reference external" href="http://lidar.io/">GRiD</a> project. Functionality that was creeping into <a class="reference external" href="http://liblas.org/">libLAS</a>
was pulled into a new library, and it was designed from the ground up to mimic
successful extract, transform, and load libraries in the geospatial software
domain. PDAL has steadily attracted more contributors as other software
developers use it to provide point cloud data translation and processing
capability to their software.</p>
<section id="how-is-point-cloud-data-different-than-raster-or-vector-geo-data">
<h3>How is point cloud data different than raster or vector geo data?<a class="headerlink" href="#how-is-point-cloud-data-different-than-raster-or-vector-geo-data" title="Permalink to this heading"></a></h3>
<p>Point cloud data are indeed very much like the typical vector point data type
of which many geospatial practitioners are familiar, but their volume causes
some significant challenges. Besides their <cite>X</cite>, <cite>Y</cite>, and <cite>Z</cite> locations, each
point often has full attribute information of other things like <cite>Intensity</cite>,
<cite>Time</cite>, <cite>Red</cite>, <cite>Green</cite>, and <cite>Blue</cite>.</p>
<p>Typical vector coverages of point data might max out at a million or so
features. Point clouds quickly get into the billions and even trillions, and
because of this specialized processing and management techniques must be used
to handle so much data efficiently.</p>
<p>The algorithms used to extract and exploit point cloud data are also
significantly different than typical vector GIS work flows, and data
organization is extremely important to be able to efficiently leverage the
available computing. These characteristics demand a library oriented toward
these approaches and PDAL achieves it.</p>
<div class="admonition note">
<p class="admonition-title">注釈</p>
<p>Possible point cloud dimension types provided and supported by PDAL
can be found at <a class="reference internal" href="dimensions.html#dimensions"><span class="std std-ref">Dimensions</span></a>.</p>
</div>
</section>
</section>
<section id="what-tasks-are-pdal-good-at">
<h2>What tasks are PDAL good at?<a class="headerlink" href="#what-tasks-are-pdal-good-at" title="Permalink to this heading"></a></h2>
<p>PDAL is great at point cloud data translation work flows. It allows users to
apply algorithms to data by providing an abstract API to the content -- freeing
users from worrying about many data format issues. PDAL's format-free worry
does come with a bit of overhead cost. In most cases this is not significant,
but for specific processing work flows with specific data, specialized tools
will certainly outperform it.</p>
<p>In exchange for possible performance penalty or data model impedance,
developers get the freedom to access data over an abstract API, a multitude of
algorithms to apply to data within easy reach, and the most complete set of
point cloud format drivers in the industry. PDAL also provides a
straightforward command line, and it extends simple generic Python processing
through Numpy. These features make it attractive to software developers, data
managers, and scientists.</p>
</section>
<section id="what-are-pdal-s-weak-points">
<h2>What are PDAL's weak points?<a class="headerlink" href="#what-are-pdal-s-weak-points" title="Permalink to this heading"></a></h2>
<p>PDAL doesn't provide a friendly GUI interface, it expects that you have the
confidence to dig into the options of <a class="reference internal" href="stages/filters.html#filters"><span class="std std-ref">Filters</span></a>, <a class="reference internal" href="stages/readers.html#readers"><span class="std std-ref">Readers</span></a>, and
<a class="reference internal" href="stages/writers.html#writers"><span class="std std-ref">Writers</span></a>. We sometimes forget that you don't always want to read source
code to figure out how things work. PDAL is an open source project in active
development, and because of that, we're always working to improve it. Please
visit <a class="reference internal" href="community.html#community"><span class="std std-ref">Community</span></a> to find out how you can participate if you are
interested. The project is always looking for contribution, and the mailing
list is the place to ask for help if you are stuck.</p>
</section>
<section id="high-level-overview">
<h2>High Level Overview<a class="headerlink" href="#high-level-overview" title="Permalink to this heading"></a></h2>
<p>PDAL is first and foremost a software library. A successful software library
must meet the needs of software developers who use it to provide its software
capabilities to their own software. In addition to its use as a software
library, PDAL provides some <a class="reference internal" href="apps/index.html#apps"><span class="std std-ref">command line applications</span></a> users can
leverage to conveniently translate, filter, and process data with PDAL.
Finally, PDAL provides <a class="reference external" href="http://python.org/">Python</a> support in the form of embedded operations
and Python extensions.</p>
<section id="core-c-software-library">
<h3>Core C++ Software Library<a class="headerlink" href="#core-c-software-library" title="Permalink to this heading"></a></h3>
<p>PDAL provides a <a class="reference internal" href="api/index.html#api"><span class="std std-ref">C++ API</span></a> software developers can use to provide
point cloud processing capabilities in their own software. PDAL is
cross-platform C++, and it can compile and run on Linux, OS X, and Windows. The
best place to learn how to use PDAL's C++ API is the <a class="reference internal" href="project/testing.html#pdal-test"><span class="std std-ref">test suite</span></a> and its <a class="reference external" href="https://github.com/PDAL/PDAL/tree/master/test/unit">source code</a>.</p>
<div class="admonition seealso">
<p class="admonition-title">参考</p>
<p>PDAL <a class="reference internal" href="tutorial/reading.html#reading"><span class="std std-ref">software</span></a> <a class="reference internal" href="development/writing.html#writing"><span class="std std-ref">development</span></a>
<a class="reference internal" href="development/writing-reader.html#writing-reader"><span class="std std-ref">tutorials</span></a> have more information on how to
use the library from a software developer's perspective.</p>
</div>
</section>
<section id="command-line-utilities">
<h3>Command Line Utilities<a class="headerlink" href="#command-line-utilities" title="Permalink to this heading"></a></h3>
<p id="index-5">PDAL provides a number of <a class="reference internal" href="apps/index.html#apps"><span class="std std-ref">applications</span></a> that allow users to
coordinate and construct point cloud processing work flows. Some key tasks
users can achieve with these applications include:</p>
<ul class="simple">
<li><p>Print <a class="reference internal" href="apps/info.html#info-command"><span class="std std-ref">info</span></a> about a data set</p></li>
<li><p>Data <a class="reference internal" href="apps/translate.html#translate-command"><span class="std std-ref">translation</span></a> from one point cloud format to
another</p></li>
<li><p>Application of exploitation algorithms</p>
<ul>
<li><p>Generate a DTM</p></li>
<li><p>Remove noise</p></li>
<li><p>Reproject from one coordinate system to another</p></li>
<li><p>Classify points as <a class="reference internal" href="apps/ground.html#ground-command"><span class="std std-ref">ground/not ground</span></a></p></li>
</ul>
</li>
<li><p><a class="reference internal" href="apps/merge.html#merge-command"><span class="std std-ref">Merge</span></a> or <a class="reference internal" href="apps/split.html#split-command"><span class="std std-ref">split</span></a> data</p></li>
<li><p><a class="reference internal" href="apps/tindex.html#tindex-command"><span class="std std-ref">Catalog</span></a> collections of data</p></li>
</ul>
<div class="admonition note">
<p class="admonition-title">注釈</p>
<p>The command line utilities are often simply <a class="reference internal" href="apps/pipeline.html#pipeline-command"><span class="std std-ref">pipeline</span></a> and
<a class="reference internal" href="pipeline.html#pipeline"><span class="std std-ref">Pipeline</span></a> collected into a convenient application. In
many cases you can replicate the functionality of an application
entirely within a single pipeline.</p>
</div>
</section>
<section id="python-api">
<h3>Python API<a class="headerlink" href="#python-api" title="Permalink to this heading"></a></h3>
<p id="index-6">PDAL supports both embedding <a class="reference external" href="http://python.org/">Python</a> and extending with <a class="reference external" href="http://python.org/">Python</a>. These
allow you to dynamically interact with point cloud data in a more
comfortable and familiar language environment for geospatial practitioners.</p>
<div class="admonition seealso">
<p class="admonition-title">参考</p>
<p>The <a class="reference internal" href="python.html#python"><span class="std std-ref">Python</span></a> document contains information on how to
install and use the PDAL Python extension.</p>
</div>
</section>
<section id="julia-plugin">
<h3>Julia Plugin<a class="headerlink" href="#julia-plugin" title="Permalink to this heading"></a></h3>
<p id="index-7">PDAL supports embedding <a class="reference external" href="https://julialand.org">Julia</a> filters. These allow you to dynamically
interact with point cloud data in a more comfortable and familiar language
environment for geospatial practitioners, while still maintaining high
performance.</p>
<p>Additionally the TypedTables.jl, RoamesGeometry.jl and AcceleratedArrays.jl
libraries provide some very high-level interfaces for writing efficient
filters.</p>
<div class="admonition seealso">
<p class="admonition-title">参考</p>
<p>The github repo at <a class="reference external" href="https://github.com/cognitive-earth/PDAL-julia">https://github.com/cognitive-earth/PDAL-julia</a> contains
a docker image, build instructions and some sample filters.</p>
<p>Documentation for the stage <a class="reference internal" href="stages/filters.julia.html#filters-julia"><span class="std std-ref">filters.julia</span></a></p>
</div>
</section>
</section>
<section id="conclusion">
<h2>Conclusion<a class="headerlink" href="#conclusion" title="Permalink to this heading"></a></h2>
<p>PDAL is an open source project for translating, filtering, and processing
point cloud data. It provides a C++ API, command line utilities, and Python
extensions. There are many open source software projects for interacting
with point cloud data, and PDAL's niche is in processing, translation,
and automation.</p>
</section>
</section>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="download.html" class="btn btn-neutral float-right" title="Download" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="index.html" class="btn btn-neutral float-left" title="PDAL - Point Data Abstraction Library" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<div class="info">
<a class="logo-link" href="https://hobu.co">
<div class="hobu-logo"></div>
</a>
<div class="copyright">
© 2024
<a href="https://github.com/abellgithub">Andrew Bell</a>,
<a href="https://github.com/chambbj">Brad Chambers</a>,
<a href="http://github.com/hobu">Howard Butler</a>,
and
<a href="https://github.com/PDAL/PDAL/graphs/contributors">others</a>.
最終更新: 8月 04, 2024
</div>
</div>
</footer>
</div>
</div>
</section>
</div>
<script>
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
<div class="footer">
<div class="container">
© 2024
<a href="http://github.com/hobu">Howard Butler</a>,
<a href="http://github.com/mpgerlek">Michael Gerlek</a>,
and
<a href="https://github.com/PDAL/PDAL/graphs/contributors">others</a>,
Last updated
on 8月 04, 2024.
</div>
</div>
</body>
</html>