ASPRS LIDAR Data Exchange Format (LAS) Reader/Writer

Transcription

1 FME Readers and Writers 2013 SP1 ASPRS LIDAR Data Exchange Format (LAS) Reader/Writer Format Note: This format is not supported by FME Base Edition. The American Society Photogrammetry and Remote Sensing (ASPRS) LIDAR (LAS) Reader allows FME to read LIDAR (data exchange format standard) LAS specifications. Overview The LAS file is intended to contain LIDAR point records. The data will generally be put into this format from software (provided by LIDAR hardware vendors) which combines GPS, IMU, and laser pulse range data to produce X, Y, and Z point data. The intention of the data format is to provide an open format that allows different LIDAR hardware and software tools to output data in a common format. FME supports LAS versions 1.0, 1.1, and 1.2. The format contains binary data consisting of a header block, Variable Length Records (VLRs), and point data. Note: Reading and writing of VLRs is not currently supported; only defined georeferencing information VLRs are supported. About Point Clouds A point cloud is a type of geometry that is useful for storing large amounts of data, typically gathered from LIDAR applications. The use of LIDAR allows for fast and accurate collection of data, such as for forestry canopy measurements, or landscape modeling. Point cloud geometry allows for quick and efficient processing of a large collection of vertices in 3D space that represent the external surfaces of objects. Together, these vertices form a model which can be transformed, and visualized. Some operations of the point cloud geometry involve thinning, splitting, and combining to produce a more useable set of vertices. This is an example point cloud image:

2 Overview Associated with each vertex are a number of properties called components, which contain a value that describes the point. These component values can be used to classify different sections of the collection of points contained in the point cloud geometry. The specific set of components stored by the point cloud is referred to as the interpretation. The default value specifies the value that will be assigned to the component when no other information is available. For example, this could occur if writing a point cloud to a format that requires a certain component to be present, but that component does not exist on the input point cloud. Interpretation Allowed Values Default Value Description Intensity 1.7E +/- 308 (15 digits) 0 The magnitude of the intensity of the pulse return. Color 0 to 65,535 0 The color of the object at the point, in RGB color. Classification 0 to 65,535 0 The classification value categorizes the points into fields, such as ground, building, water, etc. Returns The return value is the return number from a pulse. Number of returns The total number of detected returns from a single pulse. Angle -90 to 90 0 The angle of the pulse that the point was scanned at. Flight line 0 to 4,294,967,295 0 The flight line number the point was detected in. Scan Direction 0 and 1 0 The direction in which a scanning mirror was directed when the point was detected. Point ID 1 to 65,535 0 This point ID is indicative of the point origin. POSIX time 1.7E +/- 308 (15 0 Used to express the time,

3 FME Readers and Writers 2013 SP1 Interpretation Allowed Values Default Value Description digits) as the number of seconds elapsed since UTC January 1st, User data 0 to 65,535 0 The user data value is for the user to use. GPS time and GPS week Flight line Edge GPS Week: 1.7E +/- 308 (15 digits) GPS Time: 0 to 65, for points on the edge, 0 otherwise. 0 Together, these two values express the time since January 6th, The GPS Week represents a week number, and the GPS time represents the number of seconds into a week. 0 The flight line edge value is a flag for points that lie on the edge of the scan, along the flight line. LAS Quick Facts About Quick Facts Tables Format Type Identifier Reader/Writer Licensing Level Dependencies Dataset Type Feature Type Typical File Extensions Automated Translation Support User-Defined Attributes Coordinate System Support Generic Color Support Spatial Index Schema Required Transaction Support Geometry Type Attribute Encoding Support LAS Both Professional None Reader: File, Writer: Directory LAS or <source_dataset_filename>.las.laz Yes No Yes No Never Not Applicable No las_type No

4 Overview Geometry Support Geometry Supported? Geometry Supported? aggregate no point no circles no point cloud yes circular arc no polygon no donut polygon no raster no elliptical arc no solid no ellipses no surface no line no text no none no z values no Point Cloud Component Data Type Notes fmepc_angle REAL64 Range: -90 to 90 fmepc_classification UINT8 fmepc_color_r UINT16 Only supported in version 1.1+ fmepc_color_g UINT16 Only supported in version 1.1+ fmepc_color_b UINT16 Only supported in version 1.1+ fmepc_flight_line_edge UINT8 Range: 0 to 1 fmepc_flight_line not supported While not directly supported, flight line will be written as point source ID if point source ID does not exist on the point cloud. fmepc_gps_time fmepc_gps_week fmepc_intensity REAL64 not supported UINT16 fmepc_number_of_returns UINT8 Range: 1 to 5 fmepc_point_source_id UINT16 Only supported in version

5 FME Readers and Writers 2013 SP1 fmepc_posix_time not supported fmepc_return UINT8 Range: 1 to 5 fmepc_scan_direction UINT8 Range: 0 to 1 fmepc_user_data UINT8 (version 1.1+) or UINT16 (version 1.0) Reader Overview FME considers a single LAS file to be a dataset. Each dataset contains a single FME point cloud feature. ASPRS Lidar Data Exchange Format (LAS) Reader Parameters Dataset Parameters Group By Filename/Dataset If you select this option, feature types are grouped by dataset, and are named using the filename of each dataset (without the path or the extension). If you do not select this option, the only feature type this reader will use is the reader type name. Schema Attributes Additional Attributes to Expose This parameter exposes Format Attributes in Workbench when you create a workspace: In a dynamic scenario, it means these attributes can be passed to the output dataset at runtime. In a non-dynamic scenario where you have multiple feature types, it is convenient to expose additional attributes from one parameter. For example, if you have ten feature types and want to expose the same attribute in each one, it is easier to define it once than it is to set each feature type individually in the workspace. Search Envelope Use Search Envelope Using the minimum and maximum x and y parameters, define a bounding box that will be used to filter the input features. Only features that interact with the bounding box are returned. If all four coordinates of the search envelope are specified as 0, the search envelope will be disabled. Clip to Search Envelope Check this box if you want to remove any portions of exported features outside the area of interest

6 Overview Writer Overview FME considers a dataset to be a directory name. The feature type of each dataset is the filename. The LAS writer distinguishes duplicate output files by appending numbers to the filenames. ASPRS Lidar Data Exchange Format (LAS) Writer Parameters ASPRS LAS Version Select the version number of ASPRS LAS from the drop-down list. Compress Files This parameter enables or disables compression when writing an LAS file. Compression significantly decreases file size; compressed files are often only 10-20% of the original size. However, compressed files take longer to read than uncompressed files. Note: This parameter applies only to machines using the Windows operating system. Feature Representation In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Attributes), this format adds the format-specific attributes described in this section. Attribute Name las_type las_file_creation_date las_file_source_id las_generating_software las_gps_time_type las_project_id Contents This will always be las_point_cloud. The date on which this file was created (LAS 1.1 and 1.2), or the date on which the data was collected (LAS 1.0). The file source ID. A value of zero is interpreted to mean that an ID has not been assigned. Description of the generating software. Specifies the meaning of GPS Time in the Point Records. Only present in LAS 1.2 or later. A value of 0 indicates that GPS time in the point record fields is GPS Week Time (the same as previous versions of LAS). A value of 1 indicates that GPS Time is standard GPS Time (satellite GPS Time) minus 1 x The offset moves the time back to near zero to improve floating point resolution. A complete Globally Unique Identifier to serve as a project ID. By assigning a Project

7 FME Readers and Writers 2013 SP1 ID and using a File Source ID (defined above) every file within a project and every point within a file can be uniquely identified, globally. las_system_identifier las_version las_vertical_coordsys_code las_vertical_datum_code las_vertical_units_code A string identifying the hardware system or operation that generated the data. The version of the LAS file. The GeoTIFF code identifying the vertical coordinate system. The GeoTIFF code identifying the vertical datum. The GeoTIFF code identifying the units of the vertical coordinate system. Format Mapping File Directives Note: FME translations were originally based entirely on Mapping Files. Mapping files still exist under the surface but the interface has been almost entirely replaced by Workbench's graphical interface. Information on mapping files is included in this manual for technical reference purposes. Mapping Files are ASCII text files that contain a series of rules that specify the FME readers, writers, and transformations (in Workbench, these are represented by transformers). A mapping file (.fme) is a series of commands for FME to perform. Mapping files use functions and factories to transform the data. They also contain the definition and parameters for the readers and writers. A mapping file can be run through the FME Quick Translator. Before FME Workbench was designed and developed (about 2001), this was the only way to configure a translation process. You can create a mapping file either by manually programming it or by using FME Workbench. In Workbench, there is still an Export as.fme tool on the toolbar. The Workbench file format itself (.fmw file) is partially a mapping file with an XML header. When FME runs a workspace it is converted into a mapping file. Since mapping files are written in a plain ASCII format, so you can use any text editor to edit them. To see what a mapping file looks like: select one or more transformers in Workbench, copy them, and then paste them in a text editor. The mapping file equivalent of those transformers will be pasted. Directives and Reader/Writer Keywords Directives are processed by the reader or writer. Directives are prefixed by the current <ReaderKeyword> or <WriterKeyword> in a mapping file. By default, the keywords for formats are the format shortname (viewable in the Formats Gallery, or in the Format Quick Facts tables

8 Overview Reader Directives The directives listed below are processed by the LAS reader. The suffixes shown are prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the LAS reader is LAS. DATASET The value for this directive is the LAS file to be read. Required LAS_DATASET /usr/data/test.las Source ASPRS LAS File(s) GROUP_BY_DATASET The value for this directive can be either Yes or No. When the value is set to No, the only feature type this reader will use is the reader type name, which in this case is LAS. When the value is set to Yes, the feature type of each dataset is the filename (without the path or the extension) of the dataset. The default value for this directive is No. Required LAS_DATASET /usr/data/test.las Source ASPRS LAS File(s) SEARCH_ENVELOPE This directive specifies a bounding box used to filter the input features. Only features that interact with the bounding box are returned. If this directive is not specified, then all features are returned.this directive is only honoured by the MITAB-based MapInfo reader in FME. This is the only MapInfo reader available on the UNIX platforms supported by FME, and can optionally be enabled on Windows platforms by renaming the mitab.dll in the FME home directory to mapinfo.dll. <ReaderKeyword>_SEARCH_ENVELOPE <minx> <miny> <maxx> <maxy>

9 FME Readers and Writers 2013 SP1 Note: If all four coordinates of the search envelope are specified as zero, the search envelope will be disabled. Optional Minimum X, Minimum Y, Maximum X, Maximum Y SEARCH_ENVELOPE_COORDINATE_SYSTEM This directive specifies the coordinate system of the search envelope if it is different than the coordinate system of the data. The COORDINATE_SYSTEM directive, which specifies the coordinate system associated with the data to be read, must always be set if the SEARCH_ENVELOPE_COORDINATE_ SYSTEM directive is set. If this directive is set, the minimum and maximum points of the search envelope are reprojected from the SEARCH_ENVELOPE_COORDINATE_SYSTEM to the reader COORDINATE_SYSTEM prior to applying the envelope. Optional <ReaderKeyword>_SEARCH_ENVELOPE_COORDINATE_SYSTEM <coordinate system> Search Envelope Coordinate System CLIP_TO_ENVELOPE This directive specifies whether or not FME should clip features to the envelope specified in the SEARCH_ENVELOPE directive. Values YES NO (default) <ReaderKeyword>_CLIP_TO_ENVELOPE [yes no] Clip To Envelope

10 Overview EXPOSED_ATTRS This directive allows the selection of format attributes to be explicitly added to the reader feature type. This is similar to exposing format attributes on a reader feature type once it has been generated; however, it is even more powerful because it enables schema-driven applications other than Workbench to access and leverage these attributes as if they were explicitly on the schema as user attributes. The result of picking a list of attributes is a comma-separated list of attribute names and types that will be added to the schema features. Currently all reader feature types will receive the same set of additional schema attributes for a given instance of the reader. Optional Not applicable. While it is possible for FME Objects applications to invoke this directive, the required format is not documented. This directive is intended for use in our GUI applications (for example, Workbench) only. Additional Attributes to Expose Writer Directives The directives listed below are processed by the LAS writer. The suffixes shown are prefixed by the current <WriterKeyword> in a mapping file. By default, the <WriterKeyword> for the LAS writer is LAS. DATASET The value for this directive is the path of the output directory where the data will be written.. Required LAS_DATASET /usr/data/ Destination ASPRS LAS Directory VERSION The version of the LAS file to be written

11 FME Readers and Writers 2013 SP1 Optional Values (default) LAS_DATASET VERSION 1.1 ASPRS LAS Version ARCGIS_LAS_DATASET This directive identifies the name of the Esri ArcGIS LAS Dataset file to create. The.lasd file produced using this directive will reference all the LAS files created by the FME LAS Writer during the translation. An.lasd file is required to work with LAS files in the Esri ArcGIS environment. By default, the.lasd file will be written to the same directory as the.las files to which it refers. To write the.lasd to a different directory, use a fully qualified path. This directive applies to machines using the Windows operating system. Note that this option is currently incompatible with compression. When writing compressed LAS files, a.lasd file will not be generated. Note: To use this directive, you must install and license both ArcGIS 10.1 (or newer) and the 3D Analyst extension. Optional Values <filename of the.lasd to create> LAS_ARCGIS_LAS_DATASET terrain.lasd ArcGIS LAS Dataset (.lasd) COMPUTE_STATISTICS_ON_ARCGIS_LAS_DATASET This directive is applicable when an ArcGIS LAS Dataset is written. It determines whether to calculate statistics for the LAS files referenced by the ArcGIS LAS Dataset. Optional

12 Overview Values Yes No (default) LAS_COMPUTE_STATISTICS_ON_ARCGIS_LAS_DATASET Yes Compute Statistics on ArcGIS LAS Dataset USE_RELATIVE_PATHS_IN_ARCGIS_LAS_DATASET This directive is applicable when an ArcGIS LAS Dataset is written. It determines whether the references to the LAS files within the ArcGIS LAS Dataset are stored using relative or absolute path names. Use relative paths when the LAS files referenced by the ArcGIS LAS Dataset will be moved from their original location (for example, moved to a server). Optional Values Yes (default) No LAS_USE_RELATIVE_PATHS_IN_ARCGIS_LAS_DATASET No Use Relative Paths in ArcGIS LAS Dataset COMPRESSION Enables or disables compression when writing an LAS file. Compression will significantly decrease file size: compressed files are often only 10-20% of the original size. However, compressed files take longer to read than uncompressed files. This directive applies to machines using the Windows operating system. Optional Values Yes No (default) LAS_COMPRESSION YES

13 FME Readers and Writers 2013 SP1 Compress Files RESCALE_COORDINATES The LAS format stores coordinates as int32 values with a scale and offset factor. Since FME stores coordinates as real64 values, there is no guarantee that LAS will be able to store the coordinate data as is. To resolve this, the LAS writer will rescale coordinates to span the int32 range ( to ) and calculate a new scale and offset factor to preserve the original coordinate values as closely as possible. However, this rescaling may slightly distort some coordinates if they were already safely storable as int32. To disable this rescaling, set this option to No. Optional Values Yes (default) No RESCALE_COORDINATES YES Re-scale Coordinates ASTM E57 Reader Writer Format Note: This format is not supported by FME Base Edition. The ASTM E57 Reader/Writer allows FME to access data in the E57 format. Overview The E57 file format is a compact, vendor-neutral format for storing point clouds, images, and metadata produced by 3D imaging systems, such as laser scanners. A single E57 file may contain any number of point clouds and rasters. E57 files are structured as a tree. A path is a string that specifies the sequence of element names when traversing the tree. Point cloud data is read from path /data3d. Raster data is read from path /images2d. An E57 file may contain attributes and geometry traits. Elements at the root of the tree are treated as attributes, e.g. /guid. Elements within a geometry node will be treated as geometry traits, e.g. /data3d/0/points/guid

14 ASTM E57 Reader Writer Note: All features will share the same attributes, but traits will differ per feature. Point Cloud Each point cloud may contain an set of components, and each component may have an data type. A mapping between E57 element and FME component may be specified through the COMPONENT_MAP directive. For example, /data3d/0/points/colorred could be mapped to FME component fmepc_color_r. The following is the set of standard E57 component names, and the corresponding default FME component name: E57 Element cartesianx cartesiany cartesianz FME Component fmepc_x fmepc_y fmepc_z sphericalrange sphericalazimuth sphericalelevation rowindex columnindex returncount returnindex timestamp intensity colorred colorgreen colorblue fmepc_return fmepc_gps_time fmepc_intensity fmepc_color_r fmepc_color_g fmepc_color_b cartesianinvalidstate sphericalinvalidstate istimestampinvalid isintensityinvalid Point clouds in E57 may have either Cartesian coordinates or spherical coordinates. If a dataset only contains spherical coordinates, the cartesianx, cartesiany, and cartesianz elements may still be selected as part of the component map, in which case the spherical values will be converted to Cartesian values

15 FME Readers and Writers 2013 SP1 Raster Each image node, e.g. /images2d/0/, contains a raster. These images may be stored as one of four representations: visualreferencerepresentation, pinholerepresentation, sphericalrepresentation, or cylindricalrepresentation. The representation type controls which additional properties are stored (see the Feature Representation section for more details). Note: One image node may actually contain two rasters: one of the set { pinholerepresentation, sphericalrepresentation, or cylindricalrepresentation}, and one visualreferencerepresentation node. In this case, the reader will produce an aggregate geometry that holds both rasters. Similarly, the writer can ingest aggregates of two rasters. Note: Raster data is stored within an E57 file as PNG or JPEG blobs. An image mask may optionally be stored separately from the image data. When reading, FME will combine the image mask and data into a single raster. Additional Notes E57 elements that that are not part of the set (i.e. user attributes, traits, or components not in the table above) should be stored in "Extensions." Each extension in a file shall be defined by a prefix and namespace. Extensions are controlled in FME through the e57_extensions{}.prefix and e57_extensions{}.uri format attributes. On reading, these attributes specify the extensions in the source dataset. On writing, these attributes may be used to define extensions. User attributes, traits, and components should be stored in extensions to ensure compatibility with other E57 readers. So for example, instead of writing a user attribute called "myattr", one might would write a user attribute called "ext:myattr", and define the "ext" extension through the e57_extensions{}.prefix and e57_extensions{}.uri format attributes. E57 Quick Facts Format Type Identifier Reader/Writer Licensing Level Dependencies Dataset Type Feature Type E57 Both Professional Reader: None Writer: None Reader: File Writer: Directory [<filename>_]<geometry>[_ <index>]

16 ASTM E57 Reader Writer Typical File Extensions.e57 Automated Translation Support User-Defined Attributes Coordinate System Support Generic Color Support Spatial Index Schema Required Transaction Support Encoding Support Geometry Type Yes Yes Yes No No No No UTF8 e57_type Band Interpretations Palette Key Interpretations Palette Value Interpretations Nodata Value PNG: Red8, Red16, Green8, Green16, Blue8, Blue16, Alpha8, Alpha16, Gray8, Gray16 JPEG: Red8, Green8, Blue8, Gray8 PNG: UInt8 JPEG: N/A PNG: RGB24 JPEG: N/A PNG: Any JPEG: N/A Cell Origin (x, y) 0.5, 0.5 Rotation Support No GCP Support No World File Support No TAB File Support No Geometry Supported? Geometry Supported? aggregate no point no circles no polygon no

17 FME Readers and Writers 2013 SP1 Geometry Supported? Geometry Supported? circular arc no raster yes donut polygon no solid no elliptical arc no surface no ellipses no text no line no z values yes None no point cloud yes Point Cloud Component Data Type Notes fmepc_angle fmepc_classification fmepc_color_r fmepc_color_g fmepc_color_b fmepc_flight_line_edge fmepc_flight_line fmepc_gps_time fmepc_gps_week fmepc_intensity fmepc_number_of_returns fmepc_point_source_id fmepc_posix_time fmepc_return fmepc_scan_direction fmepc_user_data Reader Overview FME considers a single E57 file to be a dataset. Each dataset contains one or more point cloud and raster features. ASTM E57 Reader Parameters Dataset Parameters Group By Filename/Dataset

18 ASTM E57 Reader Writer If you select this option, feature types are grouped by dataset, and are named using the filename of each dataset (without the path or the extension). If you do not select this option, the only feature type this reader will use is the reader type name. Group By Subdataset If you select this option, feature types are grouped by subdataset, and are named using the subdataset name. If you do not select this option, the only feature type this reader will use is the reader type name. If both Group by Filename and Group by Subdataset are specified, feature type names are in the format filename_subdatasetname. Point Cloud Component Mapping Click here Use this matrix to map E57 element names to FME point cloud components. Each FME component that is mapped will appear in the point cloud geometry. Schema Attributes Additional Attributes to Expose This parameter exposes Format Attributes in Workbench when you create a workspace: In a dynamic scenario, it means these attributes can be passed to the output dataset at runtime. In a non-dynamic scenario where you have multiple feature types, it is convenient to expose additional attributes from one parameter. For example, if you have ten feature types and want to expose the same attribute in each one, it is easier to define it once than it is to set each feature type individually in the workspace. Search Envelope Use Search Envelope Using the minimum and maximum x and y parameters, define a bounding box that will be used to filter the input features. Only features that interact with the bounding box are returned. If all four coordinates of the search envelope are specified as 0, the search envelope will be disabled. Clip to Search Envelope Check this box if you want to remove any portions of exported features outside the area of interest

19 FME Readers and Writers 2013 SP1 Writer Overview FME considers a dataset to be a directory name. The feature type of each dataset is the filename. ASTM E57 Writer Parameters Point Cloud Component Mapping Use this matrix to map FME point cloud components to E57 element names. Raster Default Raster Format Specifies the underlying format to which rasters are written. Feature Representation In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Attributes), this format adds the format-specific attributes described in this section. Attribute Name e57_type e57_creation_datetime e57_creation_datetime_ isatomicclockreferenced e57_extensions{}.prefix e57_extensions{}.uri e57_format_name Contents This will always be e57_point_cloud. Date and time that the file was created. This attribute will be present with a value of 1 if, and only if, the time stored in e57_creation_ datetime is obtained from an atomic clock time source. Shall be either 0 or 1. A list of extension prefixes. A list of the URI for each extension. Name of the format. Shall contain the string "ASTM E57 3D Imaging Data File". This is a reader attribute. e57_guid e57_library_version e57_geometry_index e57_version_major A globally unique identification (GUID) String for the current version of the file. The version identifier for the E57 file format library that wrote the file. The index of this point cloud or raster in the file. The major version number of the file format. This is a reader attribute. e57_version_minor The minor version number of the file format

20 ASTM E57 Reader Writer Attribute Name Contents This is a reader attribute. This format adds the following format-specific traits for point cloud geometries. Trait Name e57_acquisition_start e57_acquisition_start_ isatomicclockreferenced e57_acquisition_end e57_acquisition_end_ isatomicclockreferenced e57_atmospheric_pressure e57_description e57_guid e57_original_guids{} Contents The start date and time that the data was acquired. This attribute will be present with a value of 1 if, and only if, the time stored in e57_acquisition_start is obtained from an atomic clock time source. Shall be either 0 or 1. The end date and time that the data was acquired. This attribute will be present with a value of 1 if, and only if, the time stored in e57_acquisition_end is obtained from an atomic clock time source. Shall be either 0 or 1. The atmospheric pressure, measured at the sensor, at the time of data collection (in Pascals). A description of the point cloud. A globally unique identifier for the current version of the point cloud. A list of of globally unique identifiers identifying the data set (or sets) from which the points in this point cloud originated. e57_relative_humidity e57_sensor_hardware_version e57_sensor_model e57_sensor_serial_number e57_sensor_software_version e57_sensor_vendor e57_temperature The percentage relative humidity, measured at the sensor, at the time of data collection. The version identifier for the sensor hardware at the time of data collection. The model name or number for the sensor used to collect the points in this point cloud. The serial number for the sensor used to collect the points in this point cloud. The version identifier for the software used for the data collection. The name of the manufacturer for the sensor used to collect the points in this point cloud. The ambient temperature, measured at the sensor, at the time of data collection (in degrees Celsius). This format adds the following format-specific traits for raster geometries

21 FME Readers and Writers 2013 SP1 Trait Name e57_acquisition_datetime e57_acquisition_datetime_ isatomicclockreferenced e57_associated_pointcloud_ guid e57_description Contents The date and time that the image was acquired. This attribute will be present with a value of 1 if, and only if, the time stored in e57_acquisition_datetime is obtained from an atomic clock time source. Shall be either 0 or 1. The globally unique identifier for the point cloud object that was being acquired when the picture was taken. A user-defined description for the image. e57_image_representation e57_raster_format e57_rotation_w e57_rotation_x e57_rotation_y e57_rotation_z e57_sensor_model e57_sensor_serial_number e57_sensor_vendor e57_separate_image_mask The representation of the image. Values are visualreferencerepresentation, pinholerepresentation, sphericalrepresentation, and cylindricalrepresentation. The underlying format in which the raster is stored. Either PNGRASTER or JPEG. The scalar part of the rotation quaternion. The i coefficient of the rotation quaternion. The j coefficient of the rotation quaternion. The k coefficient of the rotation quaternion. The model name or number for the sensor. The serial number for the sensor. The name of the manufacturer for the sensor used to collect the image. Whether the image mask (alpha band) is stored in a separate blob from the data. This format adds the following format-specific traits for raster geometries with an image representation of pinholerepresentation: Trait Name e57_focal_length e57_pixel_height e57_pixel_width e57_principal_point_x e57_principal_point_y Contents The camera s focal length (in meters). The height of the pixels in the camera (in meters). The width of the pixels in the camera (in meters). The X coordinate in the image of the principal point, (in pixels). The principal point is the intersection of the z axis of the camera. The Y coordinate in the image of the principal point (in pixels)

22 ASTM E57 Reader Writer This format adds the following format-specific traits for raster geometries with an image representation of sphericalrepresentation: Trait Name e57_pixel_height e57_pixel_width Contents The width of a pixel in the image (in radians). The height of a pixel in the image (in radians). This format adds the following format-specific traits for raster geometries with an image representation of cylindricalrepresentation: Trait Name e57_pixel_height e57_pixel_width e57_principal_point_y e57_radius Contents The height of a pixel in the image (in meters). The width of a pixel in the image (in radians). The Y coordinate in the image of the principal point (in pixels). This is the intersection of the z = 0 plane with the image. The closest distance from the cylindrical image surface to the center of projection (that is, the radius of the cylinder) (in meters). Format Mapping File Directives Note: FME translations were originally based entirely on Mapping Files. Mapping files still exist under the surface but the interface has been almost entirely replaced by Workbench's graphical interface. Information on mapping files is included in this manual for technical reference purposes. Mapping Files are ASCII text files that contain a series of rules that specify the FME readers, writers, and transformations (in Workbench, these are represented by transformers). A mapping file (.fme) is a series of commands for FME to perform. Mapping files use functions and factories to transform the data. They also contain the definition and parameters for the readers and writers. A mapping file can be run through the FME Quick Translator. Before FME Workbench was designed and developed (about 2001), this was the only way to configure a translation process. You can create a mapping file either by manually programming it or by using FME Workbench. In Workbench, there is still an Export as.fme tool on the toolbar. The Workbench file format itself (.fmw file) is partially a mapping file with an XML header. When FME runs a workspace it is converted into a mapping file. Since mapping files are written in a plain ASCII format, so you can use any text editor to edit them. To see what a mapping file looks like: select one or more transformers in Workbench, copy them, and then paste them in a text editor. The mapping file equivalent of those transformers will be pasted

23 FME Readers and Writers 2013 SP1 Directives and Reader/Writer Keywords Directives are processed by the reader or writer. Directives are prefixed by the current <ReaderKeyword> or <WriterKeyword> in a mapping file. By default, the keywords for formats are the format shortname (viewable in the Formats Gallery, or in the Format Quick Facts tables. WriterDirectives The suffixes shown are prefixed by the current <WriterKeyword> in a mapping file. By default, the <WriterKeyword> for the ASTM E57 writer is E57. DATASET The path of the output directory where the data will be written. Required E57_DATASET C:\data\ Destination ASTM E57 Directory COMPONENT_MAP This directive maps each E57 element names to FME point cloud components. Values <E57 element name, FME component name>+ Required Component Mapping DEFAULT_RASTER_FORMAT This directive sets the underlying format to which rasters will be written. This may be overridden at the geometry level by setting the e57_raster_format trait. Values PNGRASTER, JPEG Optional

24 ASTM E57 Reader Writer Default Raster Format WRITE_INTEGER_COORDINATES This directive specifies whether coordinates should be written as integers instead of floating point values. Writing integer coordinates will produce smaller files, but values may be less accurate. Note that this affects all E57 elements that are mapped from fmepc_x, fmepc_y, or fmepc_z. It will not affect any elements mapped from other FME components. For example, if this option was set to Yes and fmepc_intensity was mapped to cartesianx, cartesianx would still be written as floating point. Values YES NO Optional Write Integer Coordinates