Open Source in Photogrammetry

An Overview By:Zack Stauber, CMS

zachary@stauber.org

What is open source software?

Software whose source code can be viewed by the public For more detailed list of requirements, see Open Source on

http://www.wikipedia.org/) Often there is a compiled executable available for free download Often the licensing allows the source to be modified or even sold by

third parties For all the possible licenses, see http://www.opensource.org/ The most liberal is the MIT License

Open source is based on Open Standards (i.e. file formats, modalities, practices) Open standards must be free Not patented Not derived from or dependent on another commercial product

What is so great about it? Theory

Free, no risk in trying it out (take note, small businesses) Downloadable, available without red tape (take note, government) Flexible: you can tear it apart and change it to suit your needs Open: You can verify that the source code correctly implements

industry standard practices. No black boxes, essential under “Daubert” guidelines Often several ways to implement things in evolving fields Third parties can correct software and submit patches

What is so great about it? Practice

Better technical support Very few layers between you and the programmers Releases are as-fixed rather than on an annual or semiannual

schedule as with commercial software You can fix it yourself if you have to

Better operating systems support Often written on open source compilers so the code is already

cross platform Better international support

Programming groups for larger software applications often extend to many nations so they have built in support for other languages, currencies, time-zones, etc.

Examples: PostgreSQL

What is so great about it? Practice

Stable Programmers are often the first and most demanding users, so it

has to work, or else the programmer wouldn't bother making it Spreads by web searches or word-of-mouth, so overwhelming

advertising money cannot spread useless products by brute force Examples: Linux, Firefox, OpenOffice, GDAL

Generic Decentralized international programming groups and a wider

variety of users often incorporates more and more varied user requests

Examples: Linux, GDAL, PostgreSQL

What kind of idiots would give away all that effort for free?

Originally: universities and other government agencies Many commercial software applications originated as university

projects (e.g. GRASS). More than a few became commercial businesses in the early days (e.g. Khoros). Boo!

Also, software was ruled patentable (may be about to overturn) and universities could hold and make money on patents (thank you Strom Thurmond) so it decreased

What kind of idiots would give away all that effort for free?

Later: innovative businesses Only cheap software with many users can be sold as a product

(e.g. ArcGIS, TatukGIS, IDRISI) Mashups vs. GIS analysis vs. data production = exponential Market model shows hyper expensive software cannot be sold

as a product at a net gain (e.g. Autodesk's MapGuide) Rather than selling 200 copies worldwide and providing terrible

support and no improvements, software was given away for free and services such as customizations were sold (e.g. OSSIM)

Finally the commercial trend is reversing: everyone Some companies go under and release their software for free

(e.g. Ingres, Dynamix, Netscape) or change their profit making model and release their software for free or parts of it for free (ILWIS, OpenOffice). Yay!

What about OS mapping software?

http://www.osgeo.org/ Open Source Geospatial Foundation (software)

http://www.opengeospatial.org/ Open Geospatial Consortium (standards)

Web MapServer WorldWind MapGuide MapBender MapBuilder

Desktop GRASS QGis uDig gvSIG

Industrial strength PostgreSQL/PostGIS FWTools

Programming Tools GDAL GEOS FDO GeoTools

What about photogrammetry OS?

T'aint None No seriously, there is only OSSIM GDAL is a great platform to build on

http://www.nmosgeo.org/ wants you! Can you program? Are you a math nerd? Do you like beer? 2 of 3 required (not really)