Package com.luciad.rasters

Class PixelDensity

java.lang.Object

com.luciad.rasters.PixelDensity

All Implemented Interfaces:

AutoCloseable

public final class PixelDensity
extends Object
implements AutoCloseable

A pixel density represents the number of pixel in raster data over a unit of area in a given coordinate reference.

Concretely it's a value with the following units: px² / uom². Here, 'uom' mean the unit of measure of the coordinate reference in which the pixel density is expressed. It is typically meters.

More information on this, and hints on its usages can be fount in the related article: Retrieving height data.

A typical way to create a pixel density is by converting it from a sample distance. Imagine for example that you want to sample elevation data along a line, and get an elevation value every meter. In that case, you can use the fromSampleDistance method to create a pixel density where the distance between every pixel corresponds to 1 meter.

Since:

2023.0

Constructor Summary

Constructors

Constructor	Description
PixelDensity(CoordinateReference reference, double value)	Construct a PixelDensity object.

Method Summary

Modifier and Type	Method	Description
void	close()
protected void	finalize()
static PixelDensity	fromSampleDistance(double distanceInMeters, Coordinate sampleLocation, CoordinateReference pixelDensityReference)	Creates a pixel density from a sample distance.
CoordinateReference	getReference()	Returns the pixel density coordinate reference.
double	getValue()	Returns the pixel density value.

Methods inherited from class java.lang.Object

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

Constructor Details

PixelDensity

public PixelDensity(@NotNull
 CoordinateReference reference,
 double value)

Construct a PixelDensity object.

Parameters:

reference - the coordinate reference, cannot be null

value - the density value expressed in the given coordinate reference, must be greater than 0

Method Details

finalize

protected void finalize()

Overrides:

finalize in class Object

close

public void close()

Specified by:

close in interface AutoCloseable

getValue

public double getValue()

Returns the pixel density value.

Returns:

the pixel density value.

getReference

@NotNull
public CoordinateReference getReference()

Returns the pixel density coordinate reference.

Returns:

the pixel density coordinate reference.

fromSampleDistance

@NotNull
public static PixelDensity fromSampleDistance(double distanceInMeters,
 @NotNull
 Coordinate sampleLocation,
 @NotNull
 CoordinateReference pixelDensityReference)
                                       throws IllegalArgumentException

Creates a pixel density from a sample distance.

The resulting PixelDensity, expressed in the given coordinate reference, is such that the distance between pixels corresponds roughly with the provided distance in meters at the given location.

Parameters:

distanceInMeters - the desired distance between two adjacent samples, in meters

sampleLocation - the point at which the distance between samples must be equal to distanceInMeters

pixelDensityReference - the reference in which sampleLocation, and the resulting PixelDensity, is expressed

Returns:

a pixel density that meets the requirements

Throws:

IllegalArgumentException - if pixelDensityReference is neither a grid nor a geodetic reference.