TempImage.h
Classes
- TempImage -- Temporary astronomical images. (full description)
Interface
- Public Members
- TempImage()
- TempImage (const TiledShape& mapShape, const CoordinateSystem& coordinateInfo, Int maxMemoryInMB=-1)
- TempImage (const TiledShape& mapShape, const CoordinateSystem& coordinateInfo, Double maxMemoryInMB)
- TempImage (const TempImage<T>& other)
- ~TempImage()
- TempImage<T>& operator= (const TempImage<T>& other)
- virtual ImageInterface<T>* cloneII() const
- virtual String imageType() const
- virtual Bool isPaged() const
- virtual Bool canReferenceArray() const
- virtual Bool isWritable() const
- virtual void setDefaultMask (const String& maskName)
- void removeMask()
- virtual void useMask (MaskSpecifier = MaskSpecifier())
- virtual void removeRegion (const String& name, RegionHandler::GroupType = RegionHandler::Any, Bool throwIfUnknown = True)
- virtual void attachMask (const Lattice<Bool>& mask)
- virtual Bool isMasked() const
- virtual Bool hasPixelMask() const
- virtual const Lattice<Bool>& pixelMask() const
- virtual Lattice<Bool>& pixelMask()
- virtual Bool doGetMaskSlice (Array<Bool>& buffer, const Slicer& section)
- virtual void flush()
- virtual void tempClose()
- virtual void reopen()
- virtual void resize (const TiledShape& newShape)
- virtual String name (Bool stripPath=False) const
- virtual IPosition shape() const
- virtual void set (const T& value)
- virtual void apply (T (*function)(T))
- virtual void apply (T (*function)(const T&))
- virtual void apply (const Functional<T,T>& function)
- virtual T getAt (const IPosition& where) const
- virtual void putAt (const T& value, const IPosition& where)
- virtual LatticeIterInterface<T>* makeIter (const T& navigator, Bool useRef) const
- virtual uInt advisedMaxPixels() const
- virtual IPosition doNiceCursorShape (uInt maxPixels) const
- virtual uInt maximumCacheSize() const
- virtual void setMaximumCacheSize (uInt howManyPixels)
- virtual void setCacheSizeFromPath (const IPosition& sliceShape, const IPosition& windowStart, const IPosition& windowLength, const IPosition& axisPath)
- virtual void setCacheSizeInTiles (uInt howManyTiles)
- virtual void clearCache()
- virtual void showCacheStatistics (ostream& os) const
- virtual Bool ok() const
- Protected Members
- virtual const LatticeRegion* getRegionPtr() const
- virtual Bool doGetSlice (Array<T>& buffer, const Slicer& theSlice)
- virtual void doPutSlice (const Array<T>& sourceBuffer, const IPosition& where, const IPosition& stride)
- Private Members
- void applyMaskSpecifier (const MaskSpecifier&)
- void applyMask (const String& maskName)
Review Status
- Programs:
- Tests:
Prerequisite
Etymology
The TempImage name comes from its role as the Image class for temporary
storage.
Synopsis
The class TempImage is useful for storing temporary images
for which it is not known whether they can be held in memory.
It uses class TempLattice to
hold the image in memory when it is small enough. Otherwise it is
held in a temporary file. Similarly to TempLattice
one can give the maximum memory to use to control when the image
can be held in memory.
The other Image information like coordinates, units, and miscinfo
is held in member variables and disappears when the TempImage object
is destructed.
It is possibly to temporarily close a TempImage, which only takes effect
when it is created as a PagedArray. In this way it is possible to reduce
the number of open files in case a lot of TempImage objects are used.
A temporarily closed TempImage will be reopened automatically when needed.
It can also be reopened explicitly.
Example
Motivation
The size of astronomical data can be very large. The ability to fit an
entire image into random access memory cannot be guaranteed. Paging from
disk pieces of the image appeared to be the way to deal with this problem.
Member Description
The default constructor creates an empty image.
Construct a temporary Image from shape and coordinate information.
If the image is sufficiently small, it is kept in memory.
Otherwise it is kept in a temporary disk table. It can
be forced to disk by setting maxMemoryinMB=0.
The algorithm is the same as in class
TempLattice.
TempImage (const TempImage<T>& other)
Copy constructor (reference semantics).
Destructor
TempImage<T>& operator= (const TempImage<T>& other)
Assignment operator (reference semantics).
virtual ImageInterface<T>* cloneII() const
Make a copy of the object (reference semantics).
Get the image type (returns name of derived class).
virtual Bool isPaged() const
Is the TempImage paged to disk?
Can the lattice data be referenced as an array section?
virtual Bool isWritable() const
Is the TempImage writable?
Set the default pixelmask to the mask with the given name
(which has to exist in the "masks" group).
If the image table is writable, the setting is persistent by writing
the name as a keyword.
If the given regionName is the empty string,
the default pixelmask is unset.
Delete the pixel mask attached to the TempImage.
Does nothing if there isn't one
Use the mask as specified.
If a mask was already in use, it is replaced by the new one.
Remove a region/mask belonging to the image from the given group
(which can be Any).
If a mask removed is the default mask, the image gets unmasked.
Optionally an exception is thrown if the region does not exist.
Attach a mask to the TempImage.
It replaces a probably already attached mask.
It has to have the same shape as the image.
virtual Bool isMasked() const
It a mask attached to the image?
Does the image object use a pixelmask?
This is similar to isMasked().
Get access to the pixelmask used.
An exception is thrown if the image does not use a pixelmask.
Get a section of the mask.
It throws an exception if there is no mask.
virtual void flush()
Flush the data.
Close the TempImage temporarily (if it is paged to disk).
Note that a possible mask is not closed.
It'll be reopened automatically when needed or when
reopen is called explicitly.
virtual void reopen()
If needed, reopen a temporarily closed TempLattice.
Function which changes the shape of the image (N.B. the data is thrown
away - the Image will be filled with nonsense afterwards)
virtual String name (Bool stripPath=False) const
Return the name of the current TempImage object.
It is always "Temporary_Image"
Return the shape of the image
virtual void set (const T& value)
Function which sets all of the elements in the Lattice to a value.
virtual void apply (T (*function)(T))
virtual void apply (T (*function)(const T&))
virtual void apply (const Functional<T,T>& function)
Replace every element, x, of the lattice with the result of f(x).
You must pass in the address of the function -- so the function
must be declared and defined in the scope of your program.
Both versions of apply require a function that accepts a single
argument of type T (the Lattice template actual type) and returns
a result of the same type. The first apply expects a function with
an argument passed by value; the second expects the argument to
be passed by const reference. The first form ought to run faster
for the built-in types, which may be an issue for large images
stored in memory, where disk access is not an issue.
virtual T getAt (const IPosition& where) const
virtual void putAt (const T& value, const IPosition& where)
Get or put a single pixel.
Note that the function operator () can also be used to get a pixel.
virtual LatticeIterInterface<T>* makeIter (const T& navigator, Bool useRef) const
This is the implementations of the letters for the envelope Iterator
class Not for public use
Returns the maximum recommended number of pixels for a cursor.
This is the number of pixels in a tile.
Help the user pick a cursor for most efficient access.
Maximum size - not necessarily all used. In pixels.
Set the maximum (allowed) cache size as indicated.
Set the cache size as to "fit" the indicated path.
Set the actual cache size for this Array to be be big enough for the
indicated number of tiles. This cache is not shared with PagedArrays
in other rows and is always clipped to be less than the maximum value
set using the setMaximumCacheSize member function.
tiles. Tiles are cached using a first in first out algorithm.
Clears and frees up the caches, but the maximum allowed cache size is
unchanged from when setCacheSize was called
Report on cache success.
virtual Bool ok() const
Check for symmetry in data members.
Get the region used (it always returns 0).
virtual Bool doGetSlice (Array<T>& buffer, const Slicer& theSlice)
Function which extracts an array from the map.
virtual void doPutSlice (const Array<T>& sourceBuffer, const IPosition& where, const IPosition& stride)
Function to replace the values in the map with soureBuffer.