Package org.hortonmachine.gears.io.las.utils

Class LasUtils

java.lang.Object

org.hortonmachine.gears.io.las.utils.LasUtils

public class LasUtils
extends Object

Utilities for Las handling classes.

Author:

Andrea Antonello (www.hydrologis.com)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	LasUtils.VALUETYPE

Field Summary

Fields

Modifier and Type	Field	Description
static String	CLASSIFICATION
static org.joda.time.format.DateTimeFormatter	dateTimeFormatterYYYYMMDD
static String	dateTimeFormatterYYYYMMDD_string
static String	ELEVATION
static String	ID
static String	IMPULSE
static String	INTENSITY
static String	NUM_OF_IMPULSES
static String	THE_GEOM

Constructor Summary

Constructors

Constructor	Description
LasUtils()

Method Summary

Modifier and Type	Method	Description
static org.joda.time.DateTime	adjustedStandardGpsTime2DateTime(double adjustedStandardGpsTime)	Converts las adjusted standard gps time to DateTime.
static double	avg(List<LasRecord> points, LasUtils.VALUETYPE valueType)	Calculate the avg of a value in a list of LasRecords.
static LasRecord	clone(LasRecord lasRecord)	Clone a LasRecord.
static double	dateTimeToStandardGpsTime(org.joda.time.DateTime dateTime)	Converts an date object to standard gps time.
static double	distance(LasRecord r1, LasRecord r2)	Projected distance between two points.
static double	distance3D(LasRecord r1, LasRecord r2)	Distance between two points.
static void	dumpLasFolderOverview(String folder, org.opengis.referencing.crs.CoordinateReferenceSystem crs)	Dump an overview shapefile for a las folder.
static org.geotools.feature.simple.SimpleFeatureBuilder	getLasFeatureBuilder(org.opengis.referencing.crs.CoordinateReferenceSystem crs)	Creates a builder for las data.
static String	getLasFileVersion(File lasFile)	Read just the version bytes from a las file.
static List<LasRecord>	getLasRecordsFromFeatureCollection(org.geotools.data.simple.SimpleFeatureCollection lasCollection, boolean elevIsGround)	Create a LasRecord from a collection.
static double[]	getLastVisiblePointData(LasRecord baseRecord, List<LasRecord> lasRecords, boolean useGround)	Return last visible point data for a las records points list from a given position.
static double[][]	histogram(List<LasRecord> points, LasUtils.VALUETYPE valueType, int bins)	Calculate the histogram of a list of LasRecords.
static boolean	lasRecordEqual(LasRecord dot1, LasRecord dot2)	Compare two LasRecords.
static String	lasRecordToString(LasRecord dot)	String representation for a LasRecord.
static void	smoothIDW(List<LasRecord> lasPoints, boolean useGround, double idwBuffer, IHMProgressMonitor pm)	Smooths a set of las points through the IDW method.
static org.opengis.feature.simple.SimpleFeature	tofeature(LasRecord r, Integer featureId, org.opengis.referencing.crs.CoordinateReferenceSystem crs)	Convert a record to a feature.
static org.locationtech.jts.geom.Point	toGeometry(LasRecord r)
static List<org.locationtech.jts.geom.Geometry>	triangulate(List<LasRecord> lasPoints, Double elevThres, boolean useGround, IHMProgressMonitor pm)	Triangulates a set of las points.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

THE_GEOM

public static final String THE_GEOM

See Also:

Constant Field Values

ID

public static final String ID

See Also:

Constant Field Values

ELEVATION

public static final String ELEVATION

See Also:

Constant Field Values

INTENSITY

public static final String INTENSITY

See Also:

Constant Field Values

CLASSIFICATION

public static final String CLASSIFICATION

See Also:

Constant Field Values

IMPULSE

public static final String IMPULSE

See Also:

Constant Field Values

NUM_OF_IMPULSES

public static final String NUM_OF_IMPULSES

See Also:

Constant Field Values

dateTimeFormatterYYYYMMDD_string

public static String dateTimeFormatterYYYYMMDD_string

dateTimeFormatterYYYYMMDD

public static org.joda.time.format.DateTimeFormatter dateTimeFormatterYYYYMMDD

Constructor Detail

LasUtils

public LasUtils()

Method Detail

getLasFileVersion

public static String getLasFileVersion(File lasFile)
                                throws IOException

Read just the version bytes from a las file.

This can be handy is one needs to choose version reader.

Parameters:

lasFile - the las file to check.

Returns:

the version string as "major.minor" .

Throws:

IOException

getLasFeatureBuilder

public static org.geotools.feature.simple.SimpleFeatureBuilder getLasFeatureBuilder(org.opengis.referencing.crs.CoordinateReferenceSystem crs)

Creates a builder for las data. The attributes are:

• the_geom: a point geometry
• elev
• intensity
• classification
• impulse
• numimpulse

Parameters:

crs - the CoordinateReferenceSystem.

Returns:

the builder.

tofeature

public static org.opengis.feature.simple.SimpleFeature tofeature(LasRecord r,
                                                                 Integer featureId,
                                                                 org.opengis.referencing.crs.CoordinateReferenceSystem crs)

Convert a record to a feature.

Parameters:

r - the record to convert.

featureId - an optional feature id, if not available, the id is set to -1.

crs - the crs to apply.

Returns:

the feature.

toGeometry

public static org.locationtech.jts.geom.Point toGeometry(LasRecord r)

getLasRecordsFromFeatureCollection

public static List<LasRecord> getLasRecordsFromFeatureCollection(org.geotools.data.simple.SimpleFeatureCollection lasCollection,
                                                                 boolean elevIsGround)

Create a LasRecord from a collection.

The collection has to be created with the methods of this class previously, else some fields will be missing.

Parameters:

lasCollection - the collection to convert.

elevIsGround - if true, the elevation is the ground height.

Returns:

the list of las records.

adjustedStandardGpsTime2DateTime

public static org.joda.time.DateTime adjustedStandardGpsTime2DateTime(double adjustedStandardGpsTime)

Converts las adjusted standard gps time to DateTime.

Parameters:

adjustedStandardGpsTime - the time value.

Returns:

the UTC date object.

dateTimeToStandardGpsTime

public static double dateTimeToStandardGpsTime(org.joda.time.DateTime dateTime)

Converts an date object to standard gps time.

Parameters:

dateTime - the object (UTC).

Returns:

the standard gps time in seconds.

dumpLasFolderOverview

public static void dumpLasFolderOverview(String folder,
                                         org.opengis.referencing.crs.CoordinateReferenceSystem crs)
                                  throws Exception

Dump an overview shapefile for a las folder.

Parameters:

folder - the folder.

crs - the crs to use.

Throws:

Exception

distance

public static double distance(LasRecord r1,
                              LasRecord r2)

Projected distance between two points.

Parameters:

r1 - the first point.

r2 - the second point.

Returns:

the 2D distance.

distance3D

public static double distance3D(LasRecord r1,
                                LasRecord r2)

Distance between two points.

Parameters:

r1 - the first point.

r2 - the second point.

Returns:

the 3D distance.

lasRecordToString

public static String lasRecordToString(LasRecord dot)

String representation for a LasRecord.

Parameters:

dot - the record to convert.

Returns:

the string.

lasRecordEqual

public static boolean lasRecordEqual(LasRecord dot1,
                                     LasRecord dot2)

Compare two LasRecords.

Parameters:

dot1 - the first record.

dot2 - the second record.

Returns:

true, if the records are the same.

avg

public static double avg(List<LasRecord> points,
                         LasUtils.VALUETYPE valueType)

Calculate the avg of a value in a list of LasRecords.

Parameters:

points - the records.

valueType - the value to consider.

Returns:

the avg.

histogram

public static double[][] histogram(List<LasRecord> points,
                                   LasUtils.VALUETYPE valueType,
                                   int bins)

Calculate the histogram of a list of LasRecords.

Parameters:

points - the list of points.

valueType - the value to consider.

bins - the number of bins.

Returns:

the histogram as matrix of rows num like bins and 3 columns for [binCenter, count, cummulated-normalize-count].

triangulate

public static List<org.locationtech.jts.geom.Geometry> triangulate(List<LasRecord> lasPoints,
                                                                   Double elevThres,
                                                                   boolean useGround,
                                                                   IHMProgressMonitor pm)

Triangulates a set of las points.

If a threshold is supplied, a true dsm filtering is also applied.

Parameters:

lasPoints - the list of points.

elevThres - the optional threshold for true dsm calculation.

useGround - use the ground elevation instead of z.

pm - the monitor.

Returns:

the list of triangles.

smoothIDW

public static void smoothIDW(List<LasRecord> lasPoints,
                             boolean useGround,
                             double idwBuffer,
                             IHMProgressMonitor pm)

Smooths a set of las points through the IDW method.

Note that the values in the original data are changed.

Parameters:

lasPoints - the list of points to smooth.

useGround - if true, the ground elev is smoothed instead of the z.

idwBuffer - the buffer around the points to consider for smoothing.

pm - the monitor.

getLastVisiblePointData

public static double[] getLastVisiblePointData(LasRecord baseRecord,
                                               List<LasRecord> lasRecords,
                                               boolean useGround)

Return last visible point data for a las records points list from a given position.

For the profile the min and max angles of "sight" are calculated. The min azimuth angle represents the "upper" line of sight, as thought from the zenith.

The max azimuth angle represents the "below the earth" line of sight (think of a viewer looking in direction nadir).

The return values are in an array of doubles containing:

• [0] min point elev,
• [1] min point x,
• [2] min point y,
• [3] min point progressive,
• [4] min point azimuth,
• [5] max point elev,
• [6] max point x,
• [7] max point y,
• [8] max point progressive,
• [9] max point azimuth

Parameters:

baseRecord - the record to use as center point.

lasRecords - the LasRecord points sorted by nearest from the center dot.

useGround - if true, use the ground info instead of z elevation.

Returns:

the last visible point parameters.

clone

public static LasRecord clone(LasRecord lasRecord)

Clone a LasRecord.

Parameters:

lasRecord - the record to clone.

Returns:

the duplicate new object.