Concrete MyListProcessing dedicated to image alignment. More...

#import <MyListProcessing.h>

Inheritance diagram for MyImageAligner:

Instance Methods
(oneway void)	- alignWithList:reference:refBuffer:lock:darkFrame:flatField:rectangle:cutOff:precisionThreshold:
	Start to align images in a list. More...

Instance Methods inherited from MyListProcessing
(oneway void)	- stopProcessing

Private Attributes
NSLock *	_refSpectrumLock

MyImageListItem *	_referenceItem

FFT_DATA *	_referenceSpectrum

FFT_DATA	_bufferSpectrum

MyIntegerPoint	_referenceOrigin

u_short	_side

u_short	_cutoff

u_short	_precisionThreshold

BOOL	_refSpectrumAvailable

Additional Inherited Members
Class Methods inherited from MyListProcessing
(void)	+ threadWithAttributes:
	Thread creation. More...

Protected Attributes inherited from MyListProcessing
MyIntegerRect	_cropRectangle

id	_delegate

NSEnumerator *	_list

RGB *	_darkFrame

RGB *	_flatField

bool	_processEnded

NSData *	_result

Detailed Description

Concrete MyListProcessing dedicated to image alignment.

Method Documentation

◆ alignWithList:reference:refBuffer:lock:darkFrame:flatField:rectangle:cutOff:precisionThreshold:()

- (oneway void) alignWithList:	(NSData*)	list
reference:	(NSData*)	refItem
refBuffer:	(NSData*)	refSpectrum
lock:	(NSData*)	lock
darkFrame:	(NSData*)	dark
flatField:	(NSData*)	flat
rectangle:	(MyIntegerRect)	rect
cutOff:	(double)	cutoff
precisionThreshold:	(double)	threshold

Start to align images in a list.

Parameters

list	An enumerator on the list of images to align
refItem	The reference image against which other images are aligned
dark	The stacked dark frames
flat	The stacked flat fields
rect	The default square in which alignment is searched (some images can have the square placed elsewhere).
cutoff	The frequency above which the spectrum is cleared to avoid spurious alignment on some systematic noise).
threshold	The threshold on the correlation peak standard deviation (above it, the alignment is considered failed).

The reference item spectrum is computed and stored. After return from this method, the processing starts. For each selected item given by the enumerator, its spectrum is computed and used to correlate against the reference.

The image data has the dark frame substracted from it, and is then

divided by the flat field, before Fourier transform.

The correlation peak is the alignment offset which is sent back to the calling thread by means of the processDidProgress delegate.

References _bufferSpectrum, MyListProcessing::_cropRectangle, _cutoff, MyListProcessing::_darkFrame, MyListProcessing::_delegate, MyListProcessing::_flatField, _precisionThreshold, _referenceItem, _referenceOrigin, _referenceSpectrum, _refSpectrumAvailable, _refSpectrumLock, _side, allocate_spectrum(), cutoffSpectrum(), FOR_DIRECT, FOR_INVERSE, fourier(), getImageSample(), MyIntegerRect::origin, MyImageListItem::searchSquareOrigin, MyIntegerRect::size, FFT_DATA::spectrum, and MyIntegerSize::width.