Interface Coverage

 All Known Subinterfaces:
ContinuousCoverage
,ContinuousQuadrilateralGridCoverage
,DiscreteCoverage
,DiscreteCurveCoverage
,DiscreteGridPointCoverage
,DiscretePointCoverage
,DiscreteSolidCoverage
,DiscreteSurfaceCoverage
,DiscreteTimeInstantCoverage
,GridCoverage
,HexagonalGridCoverage
,SegmentedCurveCoverage
,ThiessenPolygonCoverage
,TinCoverage
@UML(identifier="CV_Coverage", specification=ISO_19123) public interface Coverage
A function from a spatial, temporal or spatiotemporal domain to an attribute range. A coverage associates a position within its domain to a record of values of defined data types. Examples include a raster image, polygon overlay, or digital elevation matrix. The essential property of coverage is to be able to generate a value for any point within its domain. How coverage is represented internally is not a concern. For example consider the following different internal representations of coverage:
 A coverage may be represented by a set of polygons which exhaustively tile a plane (that is each point on the plane falls in precisely one polygon). The value returned by the coverage for a point is the value of an attribute of the polygon that contains the point.
 A coverage may be represented by a grid of values (a Discrete Grid Point Coverage). If the coverage is a Continuous Quadrilateral Grid Coverage using Nearest Neighbour interpolation method, then the value returned by the coverage for a point is that of the grid value whose location is nearest the point.
 Coverage may be represented by a mathematical function. The value returned by the coverage for a point is just the return value of the function when supplied the coordinates of the point as arguments.
 Coverage may be represented by combination of these. For example, coverage may be represented by a combination of mathematical functions valid over a set of polynomials.
 Since:
 GeoAPI 2.1


Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description Object
evaluate(DirectPosition point)
Return the value vector for a given point in the coverage.boolean[]
evaluate(DirectPosition point, boolean[] destination)
Return a sequence of boolean values for a given point in the coverage.byte[]
evaluate(DirectPosition point, byte[] destination)
Return a sequence of unsigned byte values for a given point in the coverage.double[]
evaluate(DirectPosition point, double[] destination)
Return a sequence of double values for a given point in the coverage.float[]
evaluate(DirectPosition point, float[] destination)
Return a sequence of float values for a given point in the coverage.int[]
evaluate(DirectPosition point, int[] destination)
Return a sequence of integer values for a given point in the coverage.Set<Record>
evaluate(DirectPosition p, Collection<String> list)
Returns a set of records of feature attribute values for the specified direct position.Set<? extends DomainObject<?>>
evaluateInverse(Record v)
Returns a set of domain objects for the specified record of feature attribute values.GeometryValuePair
find(DirectPosition p)
Returns the nearest geometryvalue pair from the specified direct position.List<? extends GeometryValuePair>
find(DirectPosition p, int limit)
Returns the sequence of geometryvalue pairs that include the domain objects nearest to the direct position and their distances from the direction position.CommonPointRule
getCommonPointRule()
Identifies the procedure to be used for evaluating the coverage at a position that falls either on a boundary between geometric objects or within the boundaries of two or more overlapping geometric objects.CoordinateReferenceSystem
getCoordinateReferenceSystem()
Returns the coordinate reference system to which the objects in its domain are referenced.Set<? extends DomainObject<?>>
getDomainElements()
Returns the set of domain objects in the domain.Set<Extent>
getDomainExtents()
Returns the extent of the domain of the coverage.Envelope
getEnvelope()
The bounding box for the coverage domain in coordinate reference system coordinates.int
getNumSampleDimensions()
The number of sample dimensions in the coverage.Collection<AttributeValues>
getRangeElements()
Returns the set of attribute values in the range.RecordType
getRangeType()
Describes the range of the coverage.RenderableImage
getRenderableImage(int xAxis, int yAxis)
Returns 2D view of this coverage as a renderable image.SampleDimension
getSampleDimension(int index)
Retrieve sample dimension information for the coverage.List<? extends Coverage>
getSources()
Returns the sources data for a coverage.Set<? extends GeometryValuePair>
list()
Returns the dictionary of geometryvalue pairs that contain the objects in the domain of the coverage each paired with its record of feature attribute values.Set<? extends GeometryValuePair>
select(Geometry s, Period t)
Returns the set of geometryvalue pairs that contain domain objects that lie within the specified geometry and period.



Method Detail

getCoordinateReferenceSystem
@UML(identifier="CRS", obligation=MANDATORY, specification=ISO_19123) CoordinateReferenceSystem getCoordinateReferenceSystem()
Returns the coordinate reference system to which the objects in its domain are referenced. This is the CRS used when accessing a coverage or grid coverage with theevaluate(\u2026)
methods. This coordinate reference system is usually different than coordinate system of the grid. It is the target coordinate reference system of thegridToCRS
math transform.Grid coverage can be accessed (reprojected) with new coordinate reference system with the
GridCoverageProcessor
component. In this case, a new instance of a grid coverage is created. Returns:
 the coordinate reference system used when accessing a coverage or
grid coverage with the
evaluate(\u2026)
methods.

getEnvelope
@UML(identifier="envelope", obligation=MANDATORY, specification=OGC_01004) Envelope getEnvelope()
The bounding box for the coverage domain in coordinate reference system coordinates. For grid coverages, the grid cells are centered on each grid coordinate. The envelope for a 2D grid coverage includes the following corner positions.
If a grid coverage does not have any associated coordinate reference system, the minimum and maximum coordinate points for the envelope will be empty sequences.(Minimum row  0.5, Minimum column  0.5) for the minimum coordinates (Maximum row  0.5, Maximum column  0.5) for the maximum coordinates
 Returns:
 the bounding box for the coverage domain in coordinate system coordinates.
 TODO:
 We need to explain the relationship with
getDomainExtents()
, if any.

getDomainExtents
@UML(identifier="domainExtent", obligation=MANDATORY, specification=ISO_19123) Set<Extent> getDomainExtents()
Returns the extent of the domain of the coverage. Extents may be specified in space, time or spacetime. The collection must contains at least one element. Returns:
 the domain extent of the coverage.

getDomainElements
@UML(identifier="domainElement", obligation=MANDATORY, specification=ISO_19123) Set<? extends DomainObject<?>> getDomainElements()
Returns the set of domain objects in the domain. The collection must contains at least one element. Returns:
 the domain elements.

getRangeElements
@UML(identifier="rangeElement", obligation=OPTIONAL, specification=ISO_19123) Collection<AttributeValues> getRangeElements()
Returns the set of attribute values in the range. The range of a coverage shall be a homogeneous collection of records. That is, the range shall have a constant dimension over the entire domain, and each field of the record shall provide a value of the same attribute type over the entire domain.In the case of a discrete coverage, the size of the range collection equals that of the domains collection. In other words, there is one instance of
AttributeValues
for each instance ofDomainObject
. Usually, these are stored values that are accessed by theevaluate
operation.In the case of a continuous coverage, there is a transfinite number of instances of
AttributeValues
for eachDomainObject
. A few instances may be stored as input for theevaluate
operation, but most are generated as needed by that operation. Returns:
 the attribute values in the range.

getRangeType
@UML(identifier="rangeType", obligation=MANDATORY, specification=ISO_19123) RecordType getRangeType()
Describes the range of the coverage. It consists of a list of attribute name/data type pairs. A simple list is the most common form of range type, butRecordType
can be used recursively to describe more complex structures. The range type for a specific coverage shall be specified in an application schema. Returns:
 the coverage range.

getCommonPointRule
@UML(identifier="commonPointRule", obligation=MANDATORY, specification=ISO_19123) CommonPointRule getCommonPointRule()
Identifies the procedure to be used for evaluating the coverage at a position that falls either on a boundary between geometric objects or within the boundaries of two or more overlapping geometric objects. The geometric objects are either domain objects or value objects. Returns:
 the procedure for evaluating the coverage on overlapping geometries.

list
@UML(identifier="list", obligation=MANDATORY, specification=ISO_19123) Set<? extends GeometryValuePair> list()
Returns the dictionary of geometryvalue pairs that contain the objects in the domain of the coverage each paired with its record of feature attribute values. In the case of an analytical coverage, the operation shall return the empty set. Returns:
 the geometryvalue pairs.

select
@UML(identifier="select", obligation=MANDATORY, specification=ISO_19123) Set<? extends GeometryValuePair> select(Geometry s, Period t)
Returns the set of geometryvalue pairs that contain domain objects that lie within the specified geometry and period. Ifs
is null, the operation shall return all geometryvalue pairs that contain domain objects withint
. If the value oft
is null, the operation shall return all geometryvalue pair that contain domain objects withins
. In the case of an analytical coverage, the operation shall return the empty set. Parameters:
s
 The spatial component.t
 The temporal component. Returns:
 the values in the given spatiotemporal domain.

find
@UML(identifier="find", obligation=MANDATORY, specification=ISO_19123) List<? extends GeometryValuePair> find(DirectPosition p, int limit)
Returns the sequence of geometryvalue pairs that include the domain objects nearest to the direct position and their distances from the direction position. The sequence shall be ordered by distance from the direct position, beginning with the record containing the domain object nearest to the direct position. The length of the sequence (the number of geometryvalue pairs returned) shall be no greater than the number specified by the parameterlimit
. The default shall be to return a single geometryvalue pair. The operation shall return a warning if the last domain object in the sequence is at a distance from the direct position equal to the distance of other domain objects that are not included in the sequence. In the case of an analytical coverage, the operation shall return the empty set.Note: This operation is useful when the domain of a coverage does not exhaustively partition the extent of the coverage. Even in that case, the first element of the sequence returned may be the geometryvalue pair that contains the input direct position. Parameters:
p
 The search position.limit
 The maximal size of the list to be returned. Returns:
 the geometryvalue pairs nearest to the given position.

find
@UML(identifier="find", obligation=MANDATORY, specification=ISO_19123) GeometryValuePair find(DirectPosition p)
Returns the nearest geometryvalue pair from the specified direct position. This is a shortcut forfind(p,1)
. Parameters:
p
 The search position. Returns:
 the geometryvalue pair nearest to the given position.

evaluate
@UML(identifier="evaluate", obligation=MANDATORY, specification=ISO_19123) Set<Record> evaluate(DirectPosition p, Collection<String> list) throws PointOutsideCoverageException, CannotEvaluateException
Returns a set of records of feature attribute values for the specified direct position. The parameterlist
is a sequence of feature attribute names each of which identifies a field of the range type. Iflist
is null, the operation shall return a value for every field of the range type. Otherwise, it shall return a value for each field included inlist
. If the direct position passed is not in the domain of the coverage, then an exception is thrown. If the input direct position falls within two or more geometric objects within the domain, the operation shall return records of feature attribute values computed according to the common point rule.Note: Normally, the operation will return a single record of feature attribute values. Parameters:
p
 The position where to evaluate.list
 The field of interest, ornull
for every fields. Returns:
 the feature attributes.
 Throws:
PointOutsideCoverageException
 if the point is outside the coverage domain.CannotEvaluateException
 if the point can not be evaluated for some other reason.

evaluate
@UML(identifier="evaluate", obligation=MANDATORY, specification=OGC_01004) Object evaluate(DirectPosition point) throws PointOutsideCoverageException, CannotEvaluateException
Return the value vector for a given point in the coverage. A value for each sample dimension is included in the vector. The default interpolation type used when accessing grid values for points which fall between grid cells is nearest neighbor. The coordinate reference system of the point is the same as the grid coverage coordinate reference system (specified by thegetCoordinateReferenceSystem()
method).Warning: This method is inherited from the legacy OGC 01004 specification and may be deprecated in a future version. We are for more experience and feedbacks on the value of this method. Parameters:
point
 Point at which to find the grid values. Returns:
 the value vector for a given point in the coverage.
 Throws:
PointOutsideCoverageException
 if the point is outside the coverage envelope.CannotEvaluateException
 if the point can not be evaluated for some other reason. See Also:
Raster.getDataElements(int, int, Object)

evaluate
@UML(identifier="evaluateAsBoolean", obligation=MANDATORY, specification=OGC_01004) boolean[] evaluate(DirectPosition point, boolean[] destination) throws PointOutsideCoverageException, CannotEvaluateException, ArrayIndexOutOfBoundsException
Return a sequence of boolean values for a given point in the coverage. A value for each sample dimension is included in the sequence. The default interpolation type used when accessing grid values for points which fall between grid cells is nearest neighbor.The coordinate reference system of the point is the same as the grid coverage coordinate reference system (specified by the
getCoordinateReferenceSystem()
method). Parameters:
point
 Point at which to find the coverage values.destination
 An optionally preallocated array in which to store the values, ornull
if none. Returns:
 a sequence of boolean values for a given point in the coverage.
If
destination
was nonnull, then it is returned. Otherwise, a new array is allocated and returned.  Throws:
PointOutsideCoverageException
 if the point is outside the coverage envelope.CannotEvaluateException
 if the point can not be evaluated for some othe reason.ArrayIndexOutOfBoundsException
 if thedestination
array is not null and too small to hold the output.

evaluate
@UML(identifier="evaluateAsByte", obligation=MANDATORY, specification=OGC_01004) byte[] evaluate(DirectPosition point, byte[] destination) throws PointOutsideCoverageException, CannotEvaluateException, ArrayIndexOutOfBoundsException
Return a sequence of unsigned byte values for a given point in the coverage. A value for each sample dimension is included in the sequence. The default interpolation type used when accessing grid values for points which fall between grid cells is nearest neighbor.The coordinate reference system of the point is the same as the grid coverage coordinate reference system (specified by the
getCoordinateReferenceSystem()
method). Parameters:
point
 Point at which to find the coverage values.destination
 An optionally preallocated array in which to store the values, ornull
if none. Returns:
 a sequence of unsigned byte values for a given point in the coverage.
If
destination
was nonnull, then it is returned. Otherwise, a new array is allocated and returned.  Throws:
PointOutsideCoverageException
 if the point is outside the coverage envelope.CannotEvaluateException
 if the point can not be evaluated for some othe reason.ArrayIndexOutOfBoundsException
 if thedestination
array is not null and too small to hold the output.

evaluate
@UML(identifier="evaluateAsInteger", obligation=MANDATORY, specification=OGC_01004) int[] evaluate(DirectPosition point, int[] destination) throws PointOutsideCoverageException, CannotEvaluateException, ArrayIndexOutOfBoundsException
Return a sequence of integer values for a given point in the coverage. A value for each sample dimension is included in the sequence. The default interpolation type used when accessing grid values for points which fall between grid cells is nearest neighbor.The coordinate reference system of the point is the same as the grid coverage coordinate reference system (specified by the
getCoordinateReferenceSystem()
method). Parameters:
point
 Point at which to find the grid values.destination
 An optionally preallocated array in which to store the values, ornull
if none. Returns:
 a sequence of integer values for a given point in the coverage.
If
destination
was nonnull, then it is returned. Otherwise, a new array is allocated and returned.  Throws:
PointOutsideCoverageException
 if the point is outside the coverage envelope.CannotEvaluateException
 if the point can not be evaluated for some othe reason.ArrayIndexOutOfBoundsException
 if thedestination
array is not null and too small to hold the output. See Also:
Raster.getPixel(int, int, int[])

evaluate
float[] evaluate(DirectPosition point, float[] destination) throws PointOutsideCoverageException, CannotEvaluateException, ArrayIndexOutOfBoundsException
Return a sequence of float values for a given point in the coverage. A value for each sample dimension is included in the sequence. The default interpolation type used when accessing grid values for points which fall between grid cells is nearest neighbor.The coordinate reference system of the point is the same as the grid coverage coordinate reference system (specified by the
getCoordinateReferenceSystem()
method). Parameters:
point
 Point at which to find the grid values.destination
 An optionally preallocated array in which to store the values, ornull
if none. Returns:
 a sequence of float values for a given point in the coverage.
If
destination
was nonnull, then it is returned. Otherwise, a new array is allocated and returned.  Throws:
PointOutsideCoverageException
 if the point is outside the coverage envelope.CannotEvaluateException
 if the point can not be evaluated for some othe reason.ArrayIndexOutOfBoundsException
 if thedestination
array is not null and too small to hold the output. See Also:
Raster.getPixel(int, int, float[])

evaluate
@UML(identifier="evaluateAsDouble", obligation=MANDATORY, specification=OGC_01004) double[] evaluate(DirectPosition point, double[] destination) throws PointOutsideCoverageException, CannotEvaluateException, ArrayIndexOutOfBoundsException
Return a sequence of double values for a given point in the coverage. A value for each sample dimension is included in the sequence. The default interpolation type used when accessing grid values for points which fall between grid cells is nearest neighbor.The coordinate reference system of the point is the same as the grid coverage coordinate reference system (specified by the
getCoordinateReferenceSystem()
method). Parameters:
point
 Point at which to find the grid values.destination
 An optionally preallocated array in which to store the values, ornull
if none. Returns:
 a sequence of double values for a given point in the coverage.
If
destination
was nonnull, then it is returned. Otherwise, a new array is allocated and returned.  Throws:
PointOutsideCoverageException
 if the point is outside the coverage envelope.CannotEvaluateException
 if the point can not be evaluated for some othe reason.ArrayIndexOutOfBoundsException
 if thedestination
array is not null and too small to hold the output. See Also:
Raster.getPixel(int, int, double[])
Departure from OGC/ISO specification:
OGC 01004 defines this method asevaluate(DirectPosition)
. GeoAPI adds thedouble[]
argument for reusing preallocated arrays, which is consistent with usage injava.awt.image.Raster
.

evaluateInverse
@UML(identifier="evaluateInverse", obligation=MANDATORY, specification=ISO_19123) Set<? extends DomainObject<?>> evaluateInverse(Record v)
Returns a set of domain objects for the specified record of feature attribute values. Normally, this method returns the set of objects in the domain that are associated with values equal to those in the input record. However, the operation may return other objects derived from those in the domain, as specified by the application schema.Example: TheevaluateInverse
operation could return a set of contours derived from the feature attribute values associated with the grid points of a grid coverage. Parameters:
v
 The feature attributes. Returns:
 the domain where the attributes are found.

getNumSampleDimensions
@UML(identifier="numSampleDimensions", obligation=MANDATORY, specification=OGC_01004) int getNumSampleDimensions()
The number of sample dimensions in the coverage. For grid coverages, a sample dimension is a band.Warning: This method is inherited from the legacy OGC 01004 specification and may be deprecated in a future version. We are for more experience and feedbacks on the value of this method. Returns:
 the number of sample dimensions in the coverage.

getSampleDimension
@UML(identifier="getSampleDimension", obligation=MANDATORY, specification=OGC_01004) SampleDimension getSampleDimension(int index) throws IndexOutOfBoundsException
Retrieve sample dimension information for the coverage. For a grid coverage a sample dimension is a band. The sample dimension information include such things as description, data type of the value (bit, byte, integer...), the no data values, minimum and maximum values and a color table if one is associated with the dimension. A coverage must have at least one sample dimension.Warning: This method is inherited from the legacy OGC 01004 specification and may be deprecated in a future version. We are for more experience and feedbacks on the value of this method. Parameters:
index
 Index for sample dimension to retrieve. Indices are numbered 0 to (n1). Returns:
 Sample dimension information for the coverage.
 Throws:
IndexOutOfBoundsException
 ifindex
is out of bounds.

getSources
@UML(identifier="getSource, numSource", obligation=MANDATORY, specification=OGC_01004) List<? extends Coverage> getSources()
Returns the sources data for a coverage. This is intended to allow applications to establish whatCoverage
s will be affected when others are updated, as well as to trace back to the "raw data".This implementation specification does not include interfaces for creating collections of coverages therefore the list size will usually be one indicating an adapted grid coverage, or zero indicating a raw grid coverage.
Warning: This method is inherited from the legacy OGC 01004 specification and may be deprecated in a future version. We are for more experience and feedbacks on the value of this method. Returns:
 the list of sources data for a coverage.
Departure from OGC/ISO specification:
Return type ofCoverage.getSource(int)
has been relaxed fromGridCoverage
toCoverage
. Instead, the return type has been constrained toGridCoverage
only inGridCoverage.getSource(int)
. This approach (return type covariance) was already used in "Spatial Referencing by Coordinates" (ISO 19111). It avoid forward dependency ofCoverage
towardGridCoverage
and give more flexibility for use ofCoverage
with nongridded sources.

getRenderableImage
RenderableImage getRenderableImage(int xAxis, int yAxis) throws UnsupportedOperationException, IndexOutOfBoundsException
Returns 2D view of this coverage as a renderable image. This optional operation allows interoperability with Java2D. If this coverage is aGridCoverage
backed by aRenderedImage
, the underlying image can be obtained with:getRenderableImage(0,1).createDefaultRendering()
 Parameters:
xAxis
 Dimension to use for the x axis.yAxis
 Dimension to use for the y axis. Returns:
 a 2D view of this coverage as a renderable image.
 Throws:
UnsupportedOperationException
 if this optional operation is not supported.IndexOutOfBoundsException
 ifxAxis
oryAxis
is out of bounds.
Departure from OGC/ISO specification:
Added this optional method for interoperability with Java2D.

