RegionHandler.h

Classes

RegionHandler -- Base class for handling regions in images (full description)

class RegionHandler

Types

enum GroupType

Regions
Masks
Any

Interface

Public Members
virtual ~RegionHandler()
virtual RegionHandler* clone() const
virtual void setObjectPtr (void* objectPtr)
virtual Bool canDefineRegion() const
virtual void setDefaultMask (const String& maskName)
virtual String getDefaultMask() const
virtual Bool defineRegion (const String& name, const ImageRegion& region, RegionHandler::GroupType, Bool overwrite = False)
virtual Bool hasRegion (const String& name, RegionHandler::GroupType = RegionHandler::Any) const
virtual ImageRegion* getRegion (const String& name, RegionHandler::GroupType = Any, Bool throwIfUnknown = True) const
virtual Bool renameRegion (const String& newName, const String& oldName, RegionHandler::GroupType = Any, Bool overwrite = False)
virtual Bool removeRegion (const String& name, RegionHandler::GroupType = Any, Bool throwIfUnknown = True)
virtual Vector<String> regionNames (RegionHandler::GroupType = Any) const
String makeUniqueRegionName (const String& rootName, uInt startNumber=1) const
virtual ImageRegion makeMask (const LatticeBase& lattice, const String& name)

Description

Review Status

Programs:
Tests:

Prerequisite

Synopsis

Persistent regions are stored as subrecords of the table keywords "regions" and "masks". The user can choose one of both keywords. Keyword "masks" is meant for true image masks, i.e. telling for each pixel if it is good or bad. Keyword "regions" is meant for true regions in an image.

This class handles defining, getting and removing such regions. It is used by class PagedImage, but it can also be used by other code to handle regions in other tables.

Another function performed by this class for PagedImage is the definition of the default region to be used with an image.

Example

Motivation

This class has 2 purposes:
  1. This untemplated code can be factored out from the templated Image classes.
  2. The functions can easily be used by other code.

Member Description

virtual ~RegionHandler()

enum GroupType

Define the possible group types (regions or masks).

virtual RegionHandler* clone() const

Make a copy of the object.

virtual void setObjectPtr (void* objectPtr)

Set the object pointer (for RegionHandlerTable's callback). Default implementation does nothing.

virtual Bool canDefineRegion() const

Can the class indeed define and handle regions? The default implementation returns False.

virtual void setDefaultMask (const String& maskName)

Set the default mask to the mask with the given name. It constructs a ImageRegion object for the new default mask. If the table is writable, the setting is persistent by writing the name as a keyword. If the given maskName is the empty string, the default mask is unset.

virtual String getDefaultMask() const

Get the name of the default mask. An empty string is returned if no default mask.

virtual Bool defineRegion (const String& name, const ImageRegion& region, RegionHandler::GroupType, Bool overwrite = False)

Define a region belonging to the table. The group type determines if it stored as a region or mask. If overwrite=False, an exception will be thrown if the region already exists in the "regions" or "masks" keyword. Otherwise the region will be removed first.
A False status is returned if the table is not writable

virtual Bool hasRegion (const String& name, RegionHandler::GroupType = RegionHandler::Any) const

Does the table have a region with the given name?

virtual ImageRegion* getRegion (const String& name, RegionHandler::GroupType = Any, Bool throwIfUnknown = True) const

Get a region belonging to the table. A zero pointer is returned if the region does not exist. The caller has to delete the ImageRegion object created.
No exception is thrown if the region does not exist.

virtual Bool renameRegion (const String& newName, const String& oldName, RegionHandler::GroupType = Any, Bool overwrite = False)

Rename a region. If a region with the new name already exists, it is deleted or an exception is thrown (depending on overwrite). The region name is looked up in the given group(s).
An exception is thrown if the old region name does not exist.

virtual Bool removeRegion (const String& name, RegionHandler::GroupType = Any, Bool throwIfUnknown = True)

Remove a region belonging to the table.
Optionally an exception is thrown if the region does not exist.
A False status is returned if the table is not writable

virtual Vector<String> regionNames (RegionHandler::GroupType = Any) const

Get the names of all regions/masks.

String makeUniqueRegionName (const String& rootName, uInt startNumber=1) const

Make a unique region name from the given root name, thus make it such that the name is not already in use for a region or mask. The root name is returned if it is already unique. Otherwise a number is appended to the root name to make it unique. The number starts at the given number and is incremented until the name is unique.

virtual ImageRegion makeMask (const LatticeBase& lattice, const String& name)

Make a mask for a lattice (e.g. a PagedImage or TempImage). It creates it with the shape and tile shape of the lattice.