Open Source in Photogrammetry An Overview By: Zack Stauber, CMS
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 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 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? Open Source Geospatial Foundation (software) / 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 wants you! Can you program? Are you a math nerd? Do you like beer? 2 of 3 required (not really)