A class interfacing images to MatrixCleaner. More...

#include <ImageMSCleaner.h>

Public Member Functions
	ImageMSCleaner ()
	Default.
	ImageMSCleaner (ImageInterface< Float > &psf, ImageInterface< Float > &dirty)
	Create a cleaner with a psf and dirty image.
	ImageMSCleaner (const ImageMSCleaner &other)
	assignmemnt constructor
ImageMSCleaner &	operator= (const ImageMSCleaner &other)
	assignment operator
	~ImageMSCleaner ()
	The destructor.
void	update (ImageInterface< Float > &dirty)
	Update the dirty image only.
void	setPsf (ImageInterface< Float > &psf)
	Change the psf image.
Set a number of scale sizes The units of the scale are pixels *void	setscales (const Int nscales, const Float scaleInc=1.0)
void	setscales (const Vector< Float > &scales)
	Set a specific set of scales.
Bool	setcontrol (CleanEnums::CleanType cleanType, const Int niter, const Float gain, const Quantity &aThreshold, const Quantity &fThreshold)
	Set up control parameters cleanType - type of the cleaning algorithm to use (HOGBOM, MULTISCALE) niter - number of iterations gain - loop gain used in cleaning (a fraction of the maximum subtracted at every iteration) aThreshold - absolute threshold to stop iterations fThreshold - fractional threshold (i.e.
Bool	setcontrol (CleanEnums::CleanType cleanType, const Int niter, const Float gain, const Quantity &threshold)
	This version of the method disables stopping on fractional threshold.
Int	iteration () const
	return how many iterations we did do
Int	numberIterations () const
void	startingIteration (const Int starting=0)
	what iteration number to start on
Int	clean (ImageInterface< Float > &model, const String &algorithm, const Int niter, const Float gain, const Quantity &threshold, const Quantity &fthresh=Quantity(0.0,"%"), Bool doPlotProgress=False)
	Clean an image.
void	setMask (ImageInterface< Float > &mask, const Float &maskThreshold=0.9)
	Set the mask mask - input mask lattice maskThreshold - if positive, the value is treated as a threshold value to determine whether a pixel is good (mask value is greater than the threshold) or has to be masked (mask value is below the threshold).
void	ignoreCenterBox (Bool ign)
	Tell the algorithm to NOT clean just the inner quarter (This is useful when multiscale clean is being used inside a major cycle for MF or WF algorithms) if True, the full image deconvolution will be attempted.
void	setSmallScaleBias (const Float x=0.5)
	Consider the case of a point source: the flux on all scales is the same, and the first scale will be chosen.
void	stopAtLargeScaleNegative ()
	During early iterations of a cycled MS Clean in mosaicing, it common to come across an ocsilatory pattern going between positive and negative in the large scale.
void	stopPointMode (Int nStopPointMode)
	Some algorithms require that the cycles be terminated when the image is dominated by point sources; if we get nStopPointMode of the smallest scale components in a row, we terminate the cycles.
Bool	queryStopPointMode () const
	After completion of cycle, querry this to find out if we stopped because of stopPointMode.
void	speedup (const Float Ndouble)
	speedup() will speed the clean iteration by raising the threshold.
Float	maxResidual ()
	Max residual after last clean.
Private Member Functions
Bool	setupMatCleaner (const String &alg, const Int niter, const Float gain, const Quantity &threshold, const Quantity &fthresh=Quantity(0.0,"%"))
	Helper function to setup some param.
Private Attributes
MatrixCleaner	matClean_p
ImageInterface< Float > *	psf_p
ImageInterface< Float > *	dirty_p
ImageInterface< Float > *	mask_p
Int	nPsfChan_p
Int	nImChan_p
Int	nPsfPol_p
Int	nImPol_p
Int	chanAxis_p
Int	polAxis_p
Int	nMaskChan_p
Int	nMaskPol_p
Vector< Float >	scales_p
Float	maskThresh_p
Float	maxResidual_p

Detailed Description

A class interfacing images to MatrixCleaner.

Intended use:

Public interface

 <h3>Review Status</h3><dl><dt>Date Reviewed:<dd>yyyy/mm/dd<dt>Test programs:<dd>tLatticeCleaner</dl>

Prerequisite

Etymology

The ImageCleaner class will use MSClean on Images.

Synopsis

This class will perform various types of Clean deconvolution on Lattices.

Example

Motivation

Thrown Exceptions

AipsError: if psf has more dimensions than the model.

Definition at line 80 of file ImageMSCleaner.h.

Constructor & Destructor Documentation

casa::ImageMSCleaner::ImageMSCleaner ( )

Default.

casa::ImageMSCleaner::ImageMSCleaner	(	ImageInterface< Float > &	psf,
		ImageInterface< Float > &	dirty
	)

Create a cleaner with a psf and dirty image.

casa::ImageMSCleaner::ImageMSCleaner ( const ImageMSCleaner & other )

assignmemnt constructor

casa::ImageMSCleaner::~ImageMSCleaner ( )

The destructor.

Member Function Documentation

Int casa::ImageMSCleaner::clean	(	ImageInterface< Float > &	model,
		const String &	algorithm,
		const Int	niter,
		const Float	gain,
		const Quantity &	threshold,
		const Quantity &	fthresh = `Quantity(0.0,"%")`,
		Bool	doPlotProgress = `False`
	)

Clean an image.

return value gives you a hint of what's happening 1 = converged 0 = not converged but behaving normally -1 = not converged and stopped on cleaning consecutive smallest scale -2 = not converged and either large scale hit negative or diverging -3 = clean is diverging rather than converging

void casa::ImageMSCleaner::ignoreCenterBox ( Bool ign )

Tell the algorithm to NOT clean just the inner quarter (This is useful when multiscale clean is being used inside a major cycle for MF or WF algorithms) if True, the full image deconvolution will be attempted.

Int casa::ImageMSCleaner::iteration ( ) const

return how many iterations we did do

Float casa::ImageMSCleaner::maxResidual ( ) [inline]

Max residual after last clean.

Definition at line 189 of file ImageMSCleaner.h.

References maxResidual_p.

Int casa::ImageMSCleaner::numberIterations ( ) const

ImageMSCleaner& casa::ImageMSCleaner::operator= ( const ImageMSCleaner & other )

assignment operator

Bool casa::ImageMSCleaner::queryStopPointMode ( ) const

After completion of cycle, querry this to find out if we stopped because of stopPointMode.

Bool casa::ImageMSCleaner::setcontrol	(	CleanEnums::CleanType	cleanType,
		const Int	niter,
		const Float	gain,
		const Quantity &	aThreshold,
		const Quantity &	fThreshold
	)

Set up control parameters cleanType - type of the cleaning algorithm to use (HOGBOM, MULTISCALE) niter - number of iterations gain - loop gain used in cleaning (a fraction of the maximum subtracted at every iteration) aThreshold - absolute threshold to stop iterations fThreshold - fractional threshold (i.e.

given w.r.t. maximum residual) to stop iterations. This parameter is specified as Quantity so it can be given in per cents.

Bool casa::ImageMSCleaner::setcontrol	(	CleanEnums::CleanType	cleanType,
		const Int	niter,
		const Float	gain,
		const Quantity &	threshold
	)

This version of the method disables stopping on fractional threshold.

void casa::ImageMSCleaner::setMask	(	ImageInterface< Float > &	mask,
		const Float &	maskThreshold = `0.9`
	)

Set the mask mask - input mask lattice maskThreshold - if positive, the value is treated as a threshold value to determine whether a pixel is good (mask value is greater than the threshold) or has to be masked (mask value is below the threshold).

Negative threshold switches mask clipping off. The mask value is used to weight the flux during cleaning. This mode is used to implement cleaning based on the signal-to-noise as opposed to the standard cleaning based on the flux. The default threshold value is 0.9, which ensures the behavior of the code is exactly the same as before this parameter has been introduced.

void casa::ImageMSCleaner::setPsf ( ImageInterface< Float > & psf )

Change the psf image.

Set a number of scale sizes The units of the scale are pixels* void casa::ImageMSCleaner::setscales	(	const Int	nscales,
		const Float	scaleInc = `1.0`
	)

void casa::ImageMSCleaner::setscales ( const Vector< Float > & scales )

Set a specific set of scales.

void casa::ImageMSCleaner::setSmallScaleBias ( const Float x = 0.5 )

Consider the case of a point source: the flux on all scales is the same, and the first scale will be chosen.

Now, consider the case of a point source with a little bit of extended structure: thats right, the largest scale will be chosen. In this case, we should provide some bias towards the small scales, or against the large scales. We do this in an ad hoc manner, multiplying the maxima found at each scale by 1.0 - itsSmallScaleBias * itsScaleSizes(scale)/itsScaleSizes(nScalesToClean-1); Typical bias values range from 0.2 to 1.0.

Bool casa::ImageMSCleaner::setupMatCleaner	(	const String &	alg,
		const Int	niter,
		const Float	gain,
		const Quantity &	threshold,
		const Quantity &	fthresh = `Quantity(0.0,"%")`
	)		`[private]`

Helper function to setup some param.

void casa::ImageMSCleaner::speedup ( const Float Ndouble )

speedup() will speed the clean iteration by raising the threshold.

This may be required if the threshold is accidentally set too low (ie, lower than can be achieved given errors in the approximate PSF).

threshold(iteration) = threshold(0) ( exp( (iteration - startingiteration)/Ndouble )/ 2.718 ) If speedup() is NOT invoked, no effect on threshold

void casa::ImageMSCleaner::startingIteration ( const Int starting = 0 )

what iteration number to start on

void casa::ImageMSCleaner::stopAtLargeScaleNegative ( )

During early iterations of a cycled MS Clean in mosaicing, it common to come across an ocsilatory pattern going between positive and negative in the large scale.

If this is set, we stop at the first negative in the largest scale.

void casa::ImageMSCleaner::stopPointMode ( Int nStopPointMode )

Some algorithms require that the cycles be terminated when the image is dominated by point sources; if we get nStopPointMode of the smallest scale components in a row, we terminate the cycles.

void casa::ImageMSCleaner::update ( ImageInterface< Float > & dirty )

Update the dirty image only.