Abstract base class for an image attributes handler. More...

#include <ImageAttrHandlerHDF5.h>

Inheritance diagram for casacore::ImageAttrHandlerHDF5:

Public Member Functions
	ImageAttrHandlerHDF5 ()
	Default construct from the image table. More...

ImageAttrHandlerHDF5 &	attachTable (const Table &image, Bool createHandler=False)
	Attach the table and return this object. More...

virtual	~ImageAttrHandlerHDF5 ()

ImageAttrHandlerHDF5 &	attachHid (const HDF5Object &hid, Bool createHandler, Bool isWritable)
	Attach the hid and return this object. More...

virtual void	flush ()
	Flush the attibrutes if needed. More...

virtual Bool	hasGroup (const String &name)
	Test if the given attribute group is present. More...

virtual Vector< String >	groupNames () const
	Get all attribute group names. More...

virtual ImageAttrGroup &	openGroup (const String &groupName)
	Get access to a group. More...

virtual ImageAttrGroup &	createGroup (const String &groupName)
	Create an attribute group with the given name. More...

virtual void	closeGroup (const String &groupName)
	Close the group with the given name. More...

Public Member Functions inherited from casacore::ImageAttrHandler
	ImageAttrHandler ()
	Default constructor. More...

virtual	~ImageAttrHandler ()

Private Attributes
Bool	itsCanWrite

CountedPtr< HDF5Group >	itsGroup

std::map< String, ImageAttrGroupHDF5 >	itsGroupMap

Detailed Description

Abstract base class for an image attributes handler.

Intended use:

Public interface

Review Status

Test programs:: tPagedmage
Demo programs:: dPagedImage

Prerequisite

ImageInterface

Etymology

This class makes it possible to store extra attributes with an image to describe atrbitrary meta information.

Synopsis

For LOFAR it was needed to store extra meta information and to be able to convert it from casacore table format to HDF5 format and vice-versa. Furthermore, it must be possible to access the information in a way that arbitrary info can be stored and retrieved.

The attributes are divided into handlers. Each handler can reside in a subtable of the image or in a handler in HDF5. All attributes in a handler have the same number of values, where each value can be a scalar or (small) array. It is possible to define units and measure info for an attribute.

Example

This example shows how to get attributes from an image. make it known to the image.

// Open the image (as readonly for the moment).
PagedImage<Float> myimage ("image.name");
// Get access to attibute handler LOFAR_SOURCE.
ImageExtrAttr& = myimage.attrHandler ("LOFAR_SOURCE");
// Get the data for some field.
Vector<String> names = ImageExtrAttr->getString("NAME");

Motivation

LOFAR needed functionality to store arbitrary attributes.

Definition at line 89 of file ImageAttrHandlerHDF5.h.

Constructor & Destructor Documentation

casacore::ImageAttrHandlerHDF5::ImageAttrHandlerHDF5 ( )

Default construct from the image table.

virtual casacore::ImageAttrHandlerHDF5::~ImageAttrHandlerHDF5 ( )

virtual

Member Function Documentation

ImageAttrHandlerHDF5& casacore::ImageAttrHandlerHDF5::attachHid	(	const HDF5Object &	hid,
		Bool	createHandler,
		Bool	isWritable
	)

Attach the hid and return this object.

It looks for the group ATTRGROUPS which contains groups defining the attribute groups. If the group does not exist, it will be added if createHandler is set. Otherwise the handler is an empty one and no groups can be added to it.

ImageAttrHandlerHDF5& casacore::ImageAttrHandlerHDF5::attachTable	(	const Table &	image,
		Bool	createHandler = `False`
	)

Attach the table and return this object.

It looks for the table keyword ATTRGROUPS which contains the subtables defining the attribute groups. If the keyword does not exist, it will be added if createHandler is set. Otherwise the handler is an empty one and no groups can be added to it.

virtual void casacore::ImageAttrHandlerHDF5::closeGroup ( const String & groupName )

virtual

Close the group with the given name.

It will flush its attributes. Nothing is done if it is not open.

Reimplemented from casacore::ImageAttrHandler.

virtual ImageAttrGroup& casacore::ImageAttrHandlerHDF5::createGroup ( const String & groupName )

virtual

Create an attribute group with the given name.

Reimplemented from casacore::ImageAttrHandler.

virtual void casacore::ImageAttrHandlerHDF5::flush ( )

virtual

Flush the attibrutes if needed.