The ASTM E57 File Format for 3D Imaging Data Exchange

Transcription

1 The ASTM E57 File Format for 3D Imaging Data Exchange Image courtesy Intelisum, Inc. Daniel Huber The Robotics Institute Carnegie Mellon University Gene V. Roe Managing Editor LiDAR News Members of the ASTM E57 Committee on 3D Imaging Systems Sub-committee on Data Interoperability

2 ASTM E57 (3D Imaging Systems) Formed in 2006 Initial focus - 3D imaging system specification and performance evaluation for applications Current focus medium-range systems and data interoperability 4 standards have been completed with 2 under development Challenges Much more work to be done due to the general lack of standards Need proactive support of industry 2

3 ASTM E57 Standards Development Completed E2544: Standard Terminology for 3D Imaging Systems E2611: Standard Practice for Best Practices for Safe Application of 3D Imaging Technology E2807: Standard Specification for 3D Imaging Data Exchange E2919: Evaluating the Performance of Systems that Measure Static, Six Degrees of Freedom (6DOF), Pose Under Development WK12373: Evaluation of Relative Range Error for Medium- Range 3D Imaging Systems WK43218: Evaluating the Point-to-point Distance Measurement Error for a 3D Imaging System 3

4 E2544: 3D Imaging Systems Terminology Due for renewal in 2016 A draft of revised definitions has been prepared Meetings should begin shortly to finalize the revised E2544. Anyone interested in participating in this review is welcome. 4

5 E2919: Pose Estimation Error Accepted in 2013 as E2919: Evaluating the Performance of Systems that Measure Static, Six Degrees of Freedom (6DOF), Pose Measures error in estimating the pose of an object Pose = Position + Orientation Primarily for advanced manufacturing Recently revised (2014) to improve ease of use. 5

6 ASTM E57 Working Groups Two work items currently active WK12373: Evaluation of Relative Range Error for Medium-Range 3D Imaging Systems WK 43218: Evaluating the Point-to-Point Distance Measurement Error for a 3D Imaging System Both work items are focused on medium-range (2 m to 150 m range) laser scanners Pulsed Amplitude-modulated continuous-wave (AM-CW) Frequency-modulated continuous-wave (FM-CW) NRCC and NIST are actively involved in laboratory testing to support development of these standards 6

7 WK12373: Relative Range Error Applies to medium range (2 m to 150 m) laser scanners Measures relative (not absolute) range error between flat plates Completed two rounds of balloting and we hope that it will be officially published by ASTM within a few weeks. E range = d meas - d ref 7

8 WK43218: Volumetric Range Error Draft currently under development Measures error in estimating the distance between two spheres in the environment 8

9 What have we done? Over the past 9+ years, we have developed an open standard for 3D imaging system data exchange. The E57 Format Store and exchange: 3D data (point clouds, range images) Associated images Meta-data to support downstream processing General purpose terrestrial, aerial, mobile Extendable Who is we? ASTM E57 Committee on 3D Imaging Systems, Sub-committee on Data Interoperability (E57.04) 9

10 Uses of 3D Imaging: Modeling and Visualization 10

11 Uses of 3D Imaging: Robotics 11

12 Uses of 3D Imaging: Civil Engineering Quality assurance Infrastructure inspection Reverse engineering 12

13 How Do People Store 3D Data Today? Proprietary Formats PTS PTX DXF Ad-Hoc Formats PLY homebrew Domain Specific Formats LAS 13

14 What s the Problem with the Status Quo? Proprietary Formats Data exchange combinatorial explosion Loss of information when converting Long-term stability Ad-Hoc Formats Storage efficiency Limited documentation Variations in implementations Limited use for data exchange Domain Specific Formats Limited applicability across domains 14

15 How Does the E57 Format Address These Problems? Proprietary Formats Data exchange combinatorial explosion Loss of information when converting Long-term stability Ad-Hoc Formats Storage efficiency Limited documentation Variations in implementations Limited use for data exchange Domain Specific Formats Limited applicability across domains The E57 Format Single, common format Reduced need to convert Standardized definition Binary storage and data compression Thorough, extensive documentation Reference implementation Widespread use General purpose, with domainspecific extendibility 15

16 The Road to the E57 Standard Specify requirements Design the format Write standard Vote on standard Encourage adoption Develop qualification process Begin version 2 Specify requirements Develop supporting software Testing Develop additional tools 16

17 Guiding Principles Reliable interoperability Data transferable between vendors Open Freely available, well documented, unrestricted, and vendor neutral Low barrier for adoption Development cost kept to a minimum Minimalist design Keep design as simple as possible Extensibility Allow new capabilities in the future without breaking core functionality 17

18 Information to Store in an E57 File Unorganized point clouds or gridded data Multiple return data Multiple data sets (but in one coordinate system) Associated images and pose information Intended for data exchange and archiving Not intended as a working format. Limit meta-information and derived information Image courtesy Intelisum, Inc. 18

19 Secondary Goals Support for internationalization Support for extremely large file sizes Self-describing e.g., should not require external lookup tables Computer readable i.e., allow automatic verification of syntax Speed and storage efficient smaller and faster than ASCII Memory efficient Allow microcontroller implementation LAS compatibility Superset of LAS functionality 19

20 Common file format types E57 Design Basics Fixed sized fields and records Flexible, self-documenting Rigid, but compact and efficient Flexible, but inefficient and more verbose E57 Format A hybrid of the two Flexible, self-documenting framework Fixed sized, user-defined records for large, repeating structures (e.g., point clouds) 20

21 E57 Hierarchical File Structure points points (PointRecord) points (PointRecord) (PointRecord) data3d (Data3D) bar bar pose (RigidBodyTransform) e57root (E57Root) pointgroupingschemes (PointGroupingSchemes) pose (RigidBodyTransform) groupingbyline (GroupingByLine) groups groups (LineGroupRecord) groups (LineGroupRecord) (LineGroupRecord) images2d (Image2D) bar bar visualreferencerepresentation (VisualReferenceRepresentation) sphericalrepresentation (SphericalRepresentation) 21

22 Parts of an E57 File Header Binary section (points) Binary section (points) Binary section (image) XML section 22

23 Error Checking Header Binary section (points) Binary section (points) Logical data stream Binary section (image) XML section 1020 byte logical block 4 byte checksum Physical data stream 23

24 Image Storage Images stored in blobs (jpg or png format) Image distortion removed Mask to handle non-rectangular images Four camera models Visual reference Pinhole Spherical Cylindrical x image y image principal point imaging plane scene center of projection z y x focal length 24

25 Extensions Extend format to add new capabilities Examples: Mobile and data archiving extension Define new element types Example las:edgeofflightline Support backward and limited forward compatibility 25

26 Implementation The libe57 software Reference implementation is critical to rapid adoption Goals Cross-platform Open source Foundation API Comprehensive Simple API Easy to use, designed for common use cases 26

27 Ongoing Work Continuing to develop, enhance and support libe57 Working with companies to help with adoption and extension of standard Beginning to work on next version the standard Advanced compression Representing uncertainty Mobile scanning Improved representation of intensity Need your help proactive volunteers 27

28 Supporting Partners Partial List ASTM International Autodesk Bechtel Corporation Bentley Systems Carnegie Mellon University Robotics Institute Course Six, Inc. FARO Technologies Inc. InteliSum, Inc. Inovx, Inc. kubit, GmbH Leica Geosystems LiDAR News Optech, Inc. PCL Quantapoint, Inc. Riegl Laser Measurement Systems GmbH Trimble Navigation Limited University of California Davis Zoller+Fröhlich GmbH and more every week 28

29 Summary E57 format A standard format for storing data from 3D imaging systems libe57 A free reference implementation of the E57 standard ( Interested in helping out? Contact me: Gene V. Roe (gene.roe@lidarnews.com) 29

30 ASTM E57 Working Groups Two work items currently active WK12373: Evaluation of Relative Range Error for Medium-Range 3D Imaging Systems WK 43218: Evaluating the Point-to-Point Distance Measurement Error for a 3D Imaging System Both work items are focused on medium-range (2 m to 150 m range) laser scanners Pulsed Amplitude-modulated continuous-wave (AM-CW) Frequency-modulated continuous-wave (FM-CW) NRCC and NIST are actively involved in laboratory testing to support development of these standards 30

31 E2544: 3D Imaging Systems Terminology Due for renewal in 2016 A draft of revised definitions has been prepared Meetings should begin shortly to finalize the revised E2544. Anyone interested in participating in this review is welcome. 31

32 E2919: Pose Estimation Error Accepted in 2013 as E2919: Evaluating the Performance of Systems that Measure Static, Six Degrees of Freedom (6DOF), Pose Measures error in estimating the pose of an object Pose = Position + Orientation Primarily for advanced manufacturing Recently revised (2014) to improve ease of use. 32

33 WK12373: Relative Range Error Applies to medium range (2 m to 150 m) laser scanners Measures relative (not absolute) range error between flat plates Completed two rounds of balloting and we hope that it will be officially published by ASTM within a few weeks. E range = d meas - d ref 33

34 WK43218: Volumetric Range Error Draft currently under development Measures error in estimating the distance between two spheres in the environment 34