Geo::GDAL Class Reference

GDAL utility functions and a root class for raster classes. More...

Inheritance diagram for Geo::GDAL:

Classes
class	AsyncReader
	Enable asynchronous requests. More...
class	Band
	A raster band. More...
class	ColorTable
	A color table from a raster band or a color table, which can be used for a band. More...
class	Dataset
	A set of associated raster bands or vector layer source. More...
class	Driver
	A driver for a specific dataset format. More...
class	Extent
class	GCP
	A ground control point for georeferencing rasters. More...
class	GeoTransform
	An array of affine transformation coefficients. More...
class	MajorObject
	An object, which holds meta data. More...
class	RasterAttributeTable
	An attribute table in a raster band. More...
class	Transformer
	This class is not yet documented for the GDAL Perl bindings. More...
class	VSIF
	A GDAL virtual file system. More...
class	XML
	A simple XML parser. More...

Public Member Functions
public method	BuildVRT ()
public method	CPLBinaryToHex ()
public method	CPLHexToBinary ()
public method	CreatePansharpenedVRT ()
public scalar	DataTypeIsComplex (scalar DataType)
public list	DataTypeValueRange (scalar DataType)
public list	DataTypes ()
public scalar	DecToDMS (scalar angle, scalar axis, scalar precision=2)
public scalar	DecToPackedDMS (scalar dec)
public method	DontUseExceptions ()
public Geo::GDAL::Driver	Driver (scalar Name)
public list	DriverNames ()
public list	Drivers ()
public method	EscapeString ()
public scalar	FindFile (scalar basename)
public method	FinderClean ()
public method	GOA2GetAccessToken ()
public method	GOA2GetAuthorizationURL ()
public method	GOA2GetRefreshToken ()
public scalar	GetCacheMax ()
public scalar	GetCacheUsed ()
public scalar	GetConfigOption (scalar key)
public scalar	GetDataTypeSize (scalar DataType)
public method	GetJPEG2000StructureAsString ()
public Geo::GDAL::Driver	IdentifyDriver (scalar path, scalar siblings)
public Geo::GDAL::Dataset	Open (hash params)
public Geo::GDAL::Dataset	OpenEx (hash params)
public list	OpenFlags ()
public Geo::GDAL::Dataset	OpenShared (scalar name, scalar access= 'ReadOnly')
public scalar	PackCharacter (scalar DataType)
public scalar	PackedDMSToDec (scalar packed)
public method	PopFinderLocation ()
public method	PushFinderLocation (scalar path)
public list	RIOResamplingTypes ()
public list	ResamplingTypes ()
public method	SetCacheMax (scalar Bytes)
public method	SetConfigOption (scalar key, scalar value)
public method	UseExceptions ()
public method	VSIFOpenExL ()
public method	VSIGetLastErrorMsg ()
public method	VSIGetLastErrorNo ()
public scalar	VersionInfo (scalar request= 'VERSION_NUM')
public scalar	errstr ()

Detailed Description

GDAL utility functions and a root class for raster classes.

Geo::GDAL wraps many GDAL utility functions and is as a root class for all GDAL raster classes. A "raster" is an object, whose core is a rectagular grid of cells, called a "band" in GDAL. Each cell contains a numeric value of a specific data type.

Definition at line 14 of file all.pm.

Member Function Documentation

public method Geo::GDAL::BuildVRT

(

)

Code:

public method Geo::GDAL::CPLBinaryToHex

(

)

Code:

public method Geo::GDAL::CPLHexToBinary

(

)

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public method Geo::GDAL::CreatePansharpenedVRT

(

)

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public scalar Geo::GDAL::DataTypeIsComplex

(

scalar

DataType

)

Package subroutine.

Parameters

DataType

A GDAL raster cell data type (one of those listed by Geo::GDAL::DataTypes).

Returns

true if the data type is a complex number.

Code:

public list Geo::GDAL::DataTypes

(

)

Package subroutine.

Returns

a list of GDAL raster cell data types. These are currently: Byte, CFloat32, CFloat64, CInt16, CInt32, Float32, Float64, Int16, Int32, UInt16, UInt32, and Unknown.

Code:

public list Geo::GDAL::DataTypeValueRange

(

scalar

DataType

)

Package subroutine.

Parameters

DataType

Data type (one of those listed by Geo::GDAL::DataTypes).

Note

Some returned values are inaccurate.

Returns

the minimum, maximum range of the data type.

Code:

public scalar Geo::GDAL::DecToDMS	(	scalar	angle,
		scalar	axis,
		scalar	precision = 2
	)

Package subroutine. Convert decimal degrees to degrees, minutes, and seconds string

Parameters

angle	A number
axis	A string specifying latitude or longitude ('Long').
precision

Returns

a string nndnn'nn.nn'"L where n is a number and L is either N or E

Code:

public scalar Geo::GDAL::DecToPackedDMS

(

scalar

dec

)

Package subroutine.

Parameters

dec	Decimal degrees

Returns

packed DMS, i.e., a number DDDMMMSSS.SS

Code:

public method Geo::GDAL::DontUseExceptions

(

)

Package subroutine. Do not use the Perl exception mechanism for GDAL messages. Instead the messages are printed to standard error.

Code:

public Geo::GDAL::Driver Geo::GDAL::Driver

(

scalar

Name

)

Package subroutine. Access a format driver.

Parameters

Name	The short name of the driver. One of Geo::GDAL::DriverNames or Geo::OGR::DriverNames.

Note

This subroutine is imported into the main namespace if Geo::GDAL is used with qw/:all/.

Returns

a Geo::GDAL::Driver object.

Code:

public list Geo::GDAL::DriverNames

(

)

Package subroutine. Available raster format drivers.

Note

Use Geo::OGR::DriverNames for vector drivers.

Returns

a list of the short names of all available GDAL raster drivers.

Code:

public list Geo::GDAL::Drivers

(

)

Package subroutine.

Note

Use Geo::OGR::Drivers for vector drivers.

Returns

a list of all available GDAL raster drivers.

Code:

public scalar Geo::GDAL::errstr

(

)

Package subroutine. Clear the error stack and return all generated GDAL error messages in one (possibly multiline) string.

Returns

the chomped error stack joined with newlines.

Code:

public method Geo::GDAL::EscapeString

(

)

Code:

public method Geo::GDAL::FinderClean

(

)

Package subroutine. Clear the set of support file search paths.

Code:

public scalar Geo::GDAL::FindFile

(

scalar

basename

)

Package subroutine. Search for GDAL support files.

An example:

use Geo::GDAL;
$a = Geo::GDAL::FindFile('pcs.csv');
print STDERR "$a\n";

Prints (for example):

c:\msys\1.0\local\share\gdal\pcs.csv

Parameters

basename

The name of the file to search for. For example 'pcs.csv'.

Returns

the path to the searched file or undef.

Code:

public scalar Geo::GDAL::GetCacheMax

(

)

Package subroutine.

Returns

maximum amount of memory (as bytes) for caching within GDAL.

Code:

public scalar Geo::GDAL::GetCacheUsed

(

)

Package subroutine.

Returns

the amount of memory currently used for caching within GDAL.

Code:

public scalar Geo::GDAL::GetConfigOption

(

scalar

key

)

Package subroutine.

Parameters

key	A GDAL config option. Consult the GDAL documentation for available options and their use.

Returns

the value of the GDAL config option.

Code:

public scalar Geo::GDAL::GetDataTypeSize

(

scalar

DataType

)

Package subroutine.

Parameters

DataType

A GDAL raster cell data type (one of those listed by Geo::GDAL::DataTypes).

Returns

the size as the number of bits.

Code:

public method Geo::GDAL::GetJPEG2000StructureAsString

(

)

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public method Geo::GDAL::GOA2GetAccessToken

(

)

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public method Geo::GDAL::GOA2GetAuthorizationURL

(

)

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public method Geo::GDAL::GOA2GetRefreshToken

(

)

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public Geo::GDAL::Driver Geo::GDAL::IdentifyDriver	(	scalar	path,
		scalar	siblings
	)

Package subroutine.

Parameters

path	a dataset path.
siblings	[optional] A list of names of files that belong to the data format.

Returns

a Geo::GDAL::Driver.

Code:

public Geo::GDAL::Dataset Geo::GDAL::Open

(

hash

params

)

Package subroutine. Open a dataset. An example, which opens an existing raster dataset for editing:

use Geo::GDAL qw/:all/;
$ds = Open(Name => 'existing.tiff', Access => 'Update');

Parameters

params

Named parameters: Name Dataset string (typically a filename). Default is '.'. Access Access type, either 'ReadOnly' or 'Update'. Default is 'ReadOnly'. Type Dataset type, either 'Raster', 'Vector', or 'Any'. Default is 'Any'. Options A hash of GDAL open options passed to candidate drivers. Default is {}. Files A list of names of files that are auxiliary to the main file. Default is [].

Note

This subroutine is imported into the main namespace if Geo::GDAL is use'd with qw/:all/.

Some datasets / dataset strings do not explicitly imply the dataset type (for example a PostGIS database). If the type is not specified in such a case the returned dataset may be of either type.

Returns

a new Geo::GDAL::Dataset object if success.

Code:

public Geo::GDAL::Dataset Geo::GDAL::OpenEx

(

hash

params

)

Package subroutine. The generic dataset open method, used internally by all Open and OpenShared methods.

Parameters

params

Named parameters: Name The name of the data set or source to open. (Default is '.') Flags A list of access mode flags. Available flags are listed by Geo::GDAL::OpenFlags(). (Default is []) Drivers A list of short names of drivers that may be used. Empty list means all. (Default is []) Options A hash of GDAL open options passed to candidate drivers. (Default is {}) Files A list of names of files that are auxiliary to the main file. (Default is [])

An example

$ds = Geo::GDAL::OpenEx(Name => 'existing.tiff', Flags => [qw/RASTER UPDATE/]);

Returns

a new Geo::GDAL::Dataset object.

Code:

public list Geo::GDAL::OpenFlags

(

)

Package subroutine.

Returns

a list of GDAL data set open modes. These are currently: ALL, GNM, RASTER, READONLY, SHARED, UPDATE, VECTOR, and VERBOSE_ERROR.

Code:

public Geo::GDAL::Dataset Geo::GDAL::OpenShared	(	scalar	name,
		scalar	access = 'ReadOnly'
	)

Package subroutine. Open a raster dataset in shared mode.

Parameters

name	Raster dataset string (typically a filename).
access	Access type, either 'ReadOnly' (the default) or 'Update'.

Returns

a new Geo::GDAL::Dataset object or undef.

Code:

public scalar Geo::GDAL::PackCharacter

(

scalar

DataType

)

Package subroutine. Get the character that is needed for Perl's pack and unpack when they are used with Geo::GDAL::Band::ReadRaster and Geo::GDAL::Band::WriteRaster. Note that Geo::GDAL::Band::ReadTile and Geo::GDAL::Band::WriteTile have simpler interfaces that do not require pack and unpack.

Parameters

DataType

A GDAL raster cell data type, typically from $band->DataType.

Returns

a character which can be used in Perl's pack and unpack.

Code:

public scalar Geo::GDAL::PackedDMSToDec

(

scalar

packed

)

Package subroutine.

Parameters

packed

DMS as a number DDDMMMSSS.SS

Returns

decimal degrees

Code:

public method Geo::GDAL::PopFinderLocation

(

)

Package subroutine. Remove the latest addition from the set of support file search paths. Note that calling this subroutine may remove paths GDAL put into the finder.

Code:

public method Geo::GDAL::PushFinderLocation

(

scalar

path

)

Package subroutine. Add a path to the set of paths from where GDAL support files are sought. Note that GDAL puts initially into the finder the current directory and value of GDAL_DATA environment variable (if it exists), installation directory (prepended with '/share/gdal' or '/Resources/gdal'), or '/usr/local/share/gdal'. It is usually only needed to add paths to the finder if using an alternate set of data files or a non-installed GDAL is used (as in testing).

Code:

public list Geo::GDAL::ResamplingTypes

(

)

Package subroutine.

Returns

a list of GDAL resampling methods. These are currently: Average, Bilinear, Cubic, CubicSpline, Lanczos, Mode, and NearestNeighbour.

Code:

public list Geo::GDAL::RIOResamplingTypes

(

)

Package subroutine.

Returns

a list of GDAL raster IO resampling methods. These are currently: Average, Bilinear, Cubic, CubicSpline, Gauss, Lanczos, Mode, and NearestNeighbour.

Code:

public method Geo::GDAL::SetCacheMax

(

scalar

Bytes

)

Package subroutine.

Parameters

Bytes

New maximum amount of memory for caching within GDAL.

Code:

public method Geo::GDAL::SetConfigOption	(	scalar	key,
		scalar	value
	)

Package subroutine.

Parameters

key	A GDAL config option. Consult the GDAL documentation for available options and their use.
value	A value for the option, typically 'YES', 'NO', undef, path, numeric value, or a filename.

Code:

public method Geo::GDAL::UseExceptions

(

)

Package subroutine. Use the Perl exception mechanism for GDAL messages (failures are confessed and warnings are warned) and collect the messages into @Geo::GDAL::error. This is the default.

Code:

public scalar Geo::GDAL::VersionInfo

(

scalar

request = 'VERSION_NUM'

)

Package subroutine.

Parameters

request

A string specifying the request. Currently either "VERSION_NUM", "RELEASE_DATE", "RELEASE_NAME", or "--version". Default is "VERSION_NUM".

Returns

Requested information.

Code:

public method Geo::GDAL::VSIFOpenExL

(

)

Code:

public method Geo::GDAL::VSIGetLastErrorMsg

(

)

Code:

public method Geo::GDAL::VSIGetLastErrorNo

(

)

Code:

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The documentation for this class was generated from the following file:

• all.pm