Wednesday, May 13, 2015

LIDAR In the Clouds - ASPRS wants ESRI's “LAZ clone” to fade away?


Five Myths about “ESRI Optimized LAS”

The Open Letter by OSGeo was delivered to ESRI, OGC, and the ASPRS last week and the initial reponses – including an email from ESRI’s founder and president Jack Dangermond – are very encouraging. Attendees of last weeks’ ASPRS conference were discussing how to respond to ESRI’s proprietary “Optimized LAS” that threatens the achievements of the open LiDAR formats LAS and LAZ that the community is using for many years already. Below five clarifications to five wrong statements overheard at these meetings:

1) Martin’s “LAZ” format is also proprietary.

Wrong. LAZ – just like LAS – is an open format. LAZ is defined by a well commented open reference implentation in C/C++ and described in a PE&RS paper published in February 2013. LAS is defined via a specification documentbut has no reference implementation. Both can be freely used by anyone and (re-)implemented on any operating system and in any programming language. For example, there is now a javascript version of LAZ that someone else created.

2) We have no argument because ESRI provides a free API for “Optimized LAS”.

Wrong. “Optimized LAS” can only be used via the mechanism, the programming language, and the operating system of ESRI’s choosing. This is the very definition of “proprietary format”. Here is what Wikipedia says:

A proprietary format is a file format of a company, organization, or individual that contains data that is ordered and stored according to a particular encoding-scheme, designed by the company or organization to be secret, such that the decoding and interpretation of this stored data is only easily accomplished with particular software or hardware that the company itself has developed. The specification of the data encoding format is not released, or underlies non-disclosure agreements.

In contrast an open format is a file format that is published and free to be used by everybody.

3) Martin’s “LAZ” format is only used by LAStools.

Wrong. Large parts of the LiDAR industry embrace LAZ and have added read & write support for the LAZ format using the open source code or the DLL. Examples are QT Modeler, Globalmapper, FME, Fugroviewer, ERDAS IMAGINE, ENVI LiDAR, Bentley Pointools, TopoDOT, FUSION, CloudCompare, Gexel R3, Pointfuse, …and many more. Notable exceptions are ArcGIS and the product line offered by Lewis Graham’s GeoCue group. We maintain an (incomplete) list of software with native LAZ support here.

4) ESRI has engineered “Optimized LAS” for the cloud and “LAZ” cannot compete.

Wrong. The extra functionality in “Optimized LAS” is a simple mash-up of LAZ with spatial indexing LAX, an optional spatial sort, and a few extra statistics. This is why ESRI’s format is also known as the “LAZ clone”. We were able to feature-match these minor engineering changes in an afternoon which – a few days later – resulted in this April Fools’ Day prank. In fact, LAZ has been used “in the cloud” for well over 4 years on OpenTopography – the first and probably the premier Web accessible LiDAR cloud service of our industry. It is also used by many other LiDAR download servers. We maintain an (incomplete) list of portals offering compressed LAZ is here.

5) ESRI’s “Optimized LAS” does not prevent people from using LAS.

ESRI is one of the largest GIS training organizations. If they teach hundreds of LiDAR novices to “optimize” their “unoptimized LAS” files while simultaneously lobbying large LiDAR providers into switching from LAS or LAZ to zLAS they will effectively destroy the current success of our open formats. Their command of the GIS market can – little by little – turn their own proprietry format into the dominant way in which LiDAR point clouds are exchanged. Then we loose our open exchange formats. Hence, ESRI’s proprietary “Optimized LAS” format “threatens” what we have achieved with LAS (and LAZ): open LiDAR data exchange and incredible LiDAR software interoperability.

This is by no means anti-ESRI campaign. We hope to work with ESRI to resolve this situation. Below an image from ESRI’s ArcNews Spring 2011 news letter about the importance of open formats, standards, and specifications …

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What all this means to me, MM, is a users' question.  LiDAR makes 3D illustration measurements in new ways. The emerging 3D-ization to support geographic curiosity is magical and will only improve in its ability to "teleport/telepresense" ourselves. Light detection and rangin is complex to begin with, required hundreds of millions if not billions of our tax dollars for its DoD and DHS purposes, has a large cost in instrumentation and collection, and involves not just singular scientists but literally teams necessary to extract value from the data investment;  should a dominating player of spatial analysis be able to intellectually capture this essence by small but proprietary schema?  Suddenly you have a new partner in "your" data a sort of implicit taking of ownership or license?  The dominate player is caught-up in how open is their open or my open in more open?    

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