Module Info
See Also
opals::IInfo

Aim of module

Extracts and reports header information of a vector or raster file (ODM, GDAL).

General description

opalsInfo extracts statistic information (number of points/lines/polygons, the bounding box, attribute information, spatial index details, etc..) from a data set input file. Currently, only ODMs are supported. However, the support of vector files, grid and tin file formats is planned for the future. In general, all information provided in the header of the file format is made available through a generic file statistics object.

See Also
Module Info

Parameter description

-inFileinput file
Type: opals::Path
Remarks: mandatory
In the future ODMs, original data files, grid and tin files can be specified as input file. Currently only ODM are supported.
-statisticfile statistics
Type: opals::DataSetStats
Remarks: output
The result of the file statistic extraction provided as generic object. Specify -outParamFile in order to store these results to an XML file.
-exportHeaderexport header features
Type: opals::Vector<opals::HeaderFeature>
Remarks: optional
Exports internally stored header information to files. This parameter is currently supported with ODMs file only.

Examples

The data used in the following example are located in the $OPALS_ROOT/demo/ directory. The example shows how to use opalsInfo to get an overview about data (including their attributes) within an odm.

As a prerequisite, the ALS point cloud data must be imported into the ODM. To achieve that, change to the demo directory and type:

opalsImport -inFile fullwave.fwf

Now, run the following command

opalsInfo -inFile fullwave.odm

which gives the following output:

[...]
14:24:23 info: Data set statistic
Filename D:\opals\demo\fullwave.odm
Point Count 67413
Line Count 0
Polygon Count 0
Minimum X-Y-Z 24820.000 311160.006 275.535
Maximum X-Y-Z 25000.000 311260.000 328.500
Point density 8.35
[...]

After a generic information block the section about the data set attributes is listed. Figure 1 captures the corresponding section from the log file.

info_example_attributes.png
Fig. 1: Attribute statistics of demo data set fullwave.fwf

A special feature of the ODM is the on-the-fly collection of statistical information of all attributes. A useful feature for checking the correctness of imported or processed data. The last five attributes (Id, FileId, LayerId, WinputCode and StructNr) are "virtual" attributes. They exist for internally reason, however, are not made persistent on disk.

With the following command

opalsNormals -infile fullwave.odm -neighbours 8 -searchRadius 1

local planes are estimated within each point of the data set. In the current example the computation succeeds for 67297 points (and fails in 116 cases). Running opalsInfo again

opalsInfo -inFile fullwave.odm

will show the newly added attributes (c.f. Figure 2). The statistics also reflect the number of successful computated plane estimations (For NormalSigma0 even less values have been set, since redundancy is required for its computation).

info_example_attributes_normals.png
Fig. 2: Attribute statistics after normals estimation

The last section of the module output covers information of the spatial index (c.f. Figure 3). The spatial index statistics is also reported after importing a data set, since it is crucial for processing the ODM. For further details please refer to section Analysing the index statistics of an ODM.

info_example_index.png
Fig. 3: Spatial index information

References

Author
jo
Date
24.5.2012