#include <FFTOp.h>

Inheritance diagram for icl::filter::FFTOp:

Public Types
enum	SizeAdaptionMode { NO_SCALE, PAD_ZERO, PAD_COPY, PAD_MIRROR, SCALE_UP, SCALE_DOWN }
	Modes how the sourceimage is to adapt before fftcomputation. More...
enum	ResultMode { TWO_CHANNEL_COMPLEX, IMAG_ONLY, REAL_ONLY, POWER_SPECTRUM, LOG_POWER_SPECTRUM, MAGNITUDE_ONLY, PHASE_ONLY, TWO_CHANNEL_MAGNITUDE_PHASE }
	Modes how the destinationimage will be created. More...
Public Member Functions
	FFTOp (ResultMode rm=LOG_POWER_SPECTRUM, SizeAdaptionMode sam=NO_SCALE, bool fftshift=true, bool forceDFT=false)
	Creates a new FFTOp-object.
	~FFTOp ()
void	setResultMode (ResultMode rm)
	Sets the resultmode.
int	getResultMode ()
	Returns the resultmode as int.
void	setSizeAdaptionMode (SizeAdaptionMode sam)
	Sets the sizeadaptionmode.
int	getSizeAdaptionMode ()
	Returns the sizeadaptionmode.
bool	getForceDFT ()
	Returns true if the diskrete fourier transfarmation shall be used, else false.
void	setForceDFT (bool pForceDFT)
	Set wether to force the diskrete fourier transformation or to use the fast fourier transformation.
void	setFFTShift (bool pFFTShift)
	Set wether to fftshift the destinationimage or not.
bool	getFFTShift ()
	Returns the current value for fftshift.
virtual void	apply (const core::ImgBase src, core::ImgBase *dst)
	Call this method to start fftcomputation.
Private Member Functions
template<class SrcT , class DstT >
void	apply_internal (const core::Img< SrcT > &src, core::Img< DstT > &dst, math::DynMatrix< std::complex< DstT > > &buf, math::DynMatrix< std::complex< DstT > > &dstBuf)
template<class T >
const core::Img< T > *	adapt_source (const core::Img< T > *src)
template<typename T >
void	apply_inplace_fftshift (math::DynMatrix< T > &m)
Private Attributes
Data *	m_data
	Class for internal params and buffers.

Detailed Description

This class implements the unary operator for the fast and discrete 2D fourier transformation. As known the fft can only be applied if the datasize is a power of 2. This implementation uses the fft as far as it can be applied and switches to the dft, so you can use it if datasize is not a power of 2 too. If MKL or IPP is available, FFTOp tries to use it if possible.

Simple Viewer Application for Arbitrary Camera Sources

      #include <ICLQuick/Common.h>
      #include <ICLFilter/FFTOp.h>
      using namespace icl;
  
      GUI gui;

      void init(){...}

      int main(int n, char **args){
        pa_init(n,args,"-input|-i(filename)",init);
        Img32f src = load(*pa("-i"));
        FFTOp fftop(FFTOp::LOG_POWER_SPECTRUM,FFTOp::NO_SCALE);
        const ImgBase *dst = fftop.apply(&src);
      // note: icl-xv must be within your PATH
        show(norm(cvt(dst)));
      }

Save the above sourcecode to a file, compile and link it. Execute it: ./appname -input pic.jpg

Result modes

These modes configure the way the destinationimage (the result of the fft) shall be returned. Different results like logpowerspectrum, real part or phase and magnitude can be obtained. (see icl::FFTOp::ResultMode)

Sizeadaption modes

These modes configure the sourceimage before processing the fft. The sourceimage can be scaled up, so that the datasize is a power of 2 (this is needed if you want to use the IPP acceleration or the faster part of the fallback). You can also scale the image down, leave it as it is or create a border and fill it with several methods. (see icl::filter::FFTOp::SizeAdaptionMode)

Intel Ipp/Intel MKL acceleration

If you own the Intel IPP or MKL library, the computation of the fft can be accelarated by using it. The IPP functions assume a datasize of power of 2 (see icl::filter::FFTOp::SizeAdaptionMode). If IPP is available on you system and the datasize is a power of 2, it will be used automatacally. If MKL is available on your system, it will be used if IPP is not available or the datasize is not a power of 2. If IPP and MKL are not available, the fallback will be used. The MKL and fallback functions support also datasizes which are not power of 2. Supported source and destinationtypes:

dst/src	icl8u	icl16s	icl32s	icl32f	icl64f
icl32f	IPP/MKL	IPP/MKL	IPP/MKL	IPP/MKL	MKL
icl64f	MKL	MKL	MKL	MKL	MKL

Benchmarks

The following benchmark has been done on Intel Dual Core 2.4GHz CPU on a PC with 2GiB RAM. Since IPP and MKL provide their fft results in a packed format, the time for unpacking is included in this benchmarks. Also IPP and MKL do not support every possible sourcetype, so time for typeconversation is also included if necessary. All times are provided in ms per channel.:

lib/size (format)	QVGA(320x240)	HVGA(480x320)	VGA(640x480)	SVGA(800x600)	XGA(1024x768)	DSVGA(1200x800)	512x512	1024x1024
IPP	-	-	-	-	-	-	4	21
MKL	1	2	7	12	36	26	6	58
FB	214	440	896	5509	1395	11064	438	1915

Member Enumeration Documentation

enum icl::filter::FFTOp::ResultMode

Modes how the destinationimage will be created.

Several resultmodes for destinationimage.

Enumerator:

TWO_CHANNEL_COMPLEX	alternates real- and imaginarypart of fftcomputation
IMAG_ONLY	imaginarypart of fftcomputation
REAL_ONLY	realpart of fftcomputation
POWER_SPECTRUM	powerspectrum of fftcomputation
LOG_POWER_SPECTRUM	logpowerspectrum of fftcomputation
MAGNITUDE_ONLY	magnitude of fftcomputation
PHASE_ONLY	phase of fftcomputation
TWO_CHANNEL_MAGNITUDE_PHASE	alternates magnitude and phase of fftcomputation

enum icl::filter::FFTOp::SizeAdaptionMode

Modes how the sourceimage is to adapt before fftcomputation.

Several sizeadaptionmodes for sourceimageadaption

Enumerator:

NO_SCALE	sourceimage stays as is
PAD_ZERO	creates a border with zeros around the sourceimage(new size is next power of 2 after originsize, or origanalsize if it is power of 2)
PAD_COPY	continues the image with copies the sourceimage(new size is next power of 2 after originsize, or origanalsize if it is power of 2)
PAD_MIRROR	mirrors the image on the edges of the sourceimage(new size is next power of 2 after originsize, or origanalsize if it is power of 2)
SCALE_UP	zooms to next higher power of 2 of originsize, or origanalsize if it is power of 2
SCALE_DOWN	zooms to next lower power of 2 of originsize, or origanalsize if it is power of 2

Constructor & Destructor Documentation

icl::filter::FFTOp::FFTOp	(	ResultMode	rm = `LOG_POWER_SPECTRUM`,
		SizeAdaptionMode	sam = `NO_SCALE`,
		bool	fftshift = `true`,
		bool	forceDFT = `false`
	)

Creates a new FFTOp-object.

Constructor. Params can be changed later.

Parameters:

rm	the resultmode
sam	the sizeadaptionmode before applying FFTOp
fftshift	wether to apply fftshift to destinationimage after fftcomputation or not*
forceDFT	wether to apply dft or fft

icl::filter::FFTOp::~FFTOp ( )

Destructor

Member Function Documentation

template<class T >

const core::Img<T>* icl::filter::FFTOp::adapt_source ( const core::Img< T > * src ) [private]

Called by apply. Adapts sourceimage to specified values(scaling, padding on so on).Possible sourceparam is: Img<icl8u>, Img<icl16s>, Img<icl32s>, Img<icl32f>, Img<icl64f>

virtual void icl::filter::FFTOp::apply	(	const core::ImgBase *	src,
		core::ImgBase **	dst
	)		`[virtual]`

Call this method to start fftcomputation.

Applies FFTOp on src and dst.

Parameters:

*src	pointer to sourceimage
**dst	pointer to pointer to destinationimage

Implements icl::filter::UnaryOp.

template<typename T >

void icl::filter::FFTOp::apply_inplace_fftshift ( math::DynMatrix< T > & m ) [private]

Applies inplace fftshift on destinationimage after fftcomputation. Possible sourceparam is: Img<icl32f> and Img<icl64f>

template<class SrcT , class DstT >

void icl::filter::FFTOp::apply_internal	(	const core::Img< SrcT > &	src,
		core::Img< DstT > &	dst,
		math::DynMatrix< std::complex< DstT > > &	buf,
		math::DynMatrix< std::complex< DstT > > &	dstBuf
	)		`[private]`

Called by apply. Applies fft/dft and resultmode. Possible sourceparam is: Img<icl8u>, Img<icl16s>, Img<icl32s>, Img<icl32f>, Img<icl64f>. Possible destinationparam is: Img<icl32f> and Img<icl64f>.

bool icl::filter::FFTOp::getFFTShift ( )

Returns the current value for fftshift.

Returns:: true if destinationimage is to be fftshifted, else false

bool icl::filter::FFTOp::getForceDFT ( )

Returns true if the diskrete fourier transfarmation shall be used, else false.

Returns:: true if dft should be used, false if fft should be used

int icl::filter::FFTOp::getResultMode ( )

Returns the resultmode as int.

Returns:: the current resultmode.

int icl::filter::FFTOp::getSizeAdaptionMode ( )

Returns the sizeadaptionmode.

Returns:: the current sizeadationmode

void icl::filter::FFTOp::setFFTShift ( bool pFFTShift )

Set wether to fftshift the destinationimage or not.

Parameters:

pFFTShift true if the destinationimage should be shifted, else false

void icl::filter::FFTOp::setForceDFT ( bool pForceDFT )

Set wether to force the diskrete fourier transformation or to use the fast fourier transformation.

Parameters:

pForceDFT

void icl::filter::FFTOp::setResultMode ( ResultMode rm )

Sets the resultmode.

Parameters:

rm	the resultmode to be set

void icl::filter::FFTOp::setSizeAdaptionMode ( SizeAdaptionMode sam )

Sets the sizeadaptionmode.

Parameters:

sam	the sizeadaptionmode to be set

Member Data Documentation

Data* icl::filter::FFTOp::m_data [private]

Class for internal params and buffers.

The documentation for this class was generated from the following file:

/home/jenkins/workspace/icl-manual-trunk/icl-manual/ICLFilter/src/ICLFilter/FFTOp.h

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Simple Viewer Application for Arbitrary Camera Sources

Result modes

Sizeadaption modes

Intel Ipp/Intel MKL acceleration

Benchmarks

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation