class for applying table look-up transformation to 3-channel integer-valued images More...

#include <LUTOp3Channel.h>

Inheritance diagram for icl::filter::LUTOp3Channel< T >:

Classes
class	Plugin
	Internal plugin class for the LUTOp3Channel. More...

Public Member Functions
	LUTOp3Channel (Plugin *p=0, icl8u shift=0)
	creates a LUT object with given lut (LUT-mode) More...

virtual	~LUTOp3Channel ()
	Destructor. More...

virtual void	apply (const core::ImgBase src, core::ImgBase *dst)
	Common Filter apply function using current mode. More...

void	setPlugin (Plugin *p)
	Sets a new plugin and re-calculates the internal LUT. More...

Plugin *	removePlugin ()
	removes the internal plugin so it is not deleted with the LUTOp More...

virtual void	apply (const core::ImgBase operand1, core::ImgBase *dst)=0
	Import unaryOps apply function without destination image. More...

virtual const core::ImgBase *	apply (const core::ImgBase *src)
	Import unaryOps apply function without destination image. More...

Public Member Functions inherited from icl::filter::UnaryOp
	UnaryOp ()
	Explicit empty constructor. More...

	UnaryOp (const UnaryOp &other)
	Explicit copy constructor. More...

UnaryOp &	operator= (const UnaryOp &other)
	Explicit declaration of the assignment operator. More...

virtual	~UnaryOp ()
	Destructor. More...

virtual ICL_DEPRECATED void	applyMT (const core::ImgBase operand1, core::ImgBase *dst, unsigned int nThreads)
	apply function for multithreaded filtering (currently even slower than using one thread) More...

virtual const core::ImgBase *	apply (const core::ImgBase *src)
	applys the filter usign an internal buffer as output image More...

void	operator() (const core::ImgBase src, core::ImgBase *dst)
	function operator (alternative for apply(src,dst) More...

const core::ImgBase *	operator() (const core::ImgBase *src)
	function operator for the implicit destination apply(src) call More...

const core::ImgBase &	operator() (const core::ImgBase &src)
	reference based function operator More...

void	setClipToROI (bool bClipToROI)
	sets if the image should be clip to ROI or not More...

void	setCheckOnly (bool bCheckOnly)
	sets if the destination image should be adapted to the source, or if it is only checked if it can be adapted. More...

bool	getClipToROI () const
	returns the ClipToROI status More...

bool	getCheckOnly () const
	returns the CheckOnly status More...

virtual void	setPropertyValue (const std::string &propertyName, const utils::Any &value)
	sets value of a property (always call call_callbacks(propertyName) or Configurable::setPropertyValue) More...

Public Member Functions inherited from icl::utils::Configurable
virtual	~Configurable ()
	virtual destructor More...

	Configurable (const Configurable &other)
	Copy constructor. More...

Configurable &	operator= (const Configurable &other)
	Assignment operator. More...

void	setConfigurableID (const std::string &ID)
	sets the ID of this configurable More...

const std::string &	getConfigurableID () const
	returns the configurables static ID More...

bool	isOrderedFlagSet () const
	returns whether the ordered flag is set More...

void	deactivateProperty (const std::string &pattern)
	adds an additional deativation pattern More...

void	deleteDeactivationPattern (const std::string &pattern)
	removed a formerly added deactivation pattern More...

std::vector< std::string >	getPropertyListWithoutDeactivated () const
	this returns a filtered list of properties (using all filters added by deactivateProperty) More...

virtual void	adaptProperty (const std::string &name, const std::string &newType, const std::string &newInfo, const std::string &newToolTip)
	this function can be used to adapt a specific property afterwards More...

void	registerCallback (const Callback &cb)
	add a callback for changed properties More...

void	removedCallback (const Callback &cb)
	removes a callback that was registered before More...

void	syncChangesTo (Configurable *others, int num=1)
	this can be used to let this instance also apply property changes to others More...

virtual std::vector< std::string >	getPropertyList () const
	returns a list of All properties, that can be set using setProperty More...

virtual bool	supportsProperty (const std::string &propertyName) const
	base implementation for property check (seaches in the property list) More...

virtual void	saveProperties (const std::string &filename, const std::vector< std::string > &propertiesToSkip=EMPTY_VEC) const
	writes all available properties into a file More...

virtual void	loadProperties (const std::string &filename, const std::vector< std::string > &propertiesToSkip=EMPTY_VEC)
	reads a camera config file from disc More...

virtual std::string	getPropertyType (const std::string &propertyName) const
	get type of property More...

virtual std::string	getPropertyInfo (const std::string &propertyName) const
	get information of a properties valid values More...

virtual Any	getPropertyValue (const std::string &propertyName) const
	returns the current value of a property or a parameter More...

virtual std::string	getPropertyToolTip (const std::string &propertyName) const
	returns the tooltip description for a given property More...

virtual int	getPropertyVolatileness (const std::string &propertyName) const
	Returns whether this property may be changed internally. More...

Private Attributes
core::Img< T >	m_oLUT
	Image that holds the lut data. More...

Plugin *	m_poPlugin
	Current plugin pointer. More...

icl8u	m_ucShift
	channel range increment (...) More...

Additional Inherited Members
Public Types inherited from icl::utils::Configurable
typedef Function< void, const Property & >	Callback
	Function type for changed properties. More...

Static Public Member Functions inherited from icl::filter::UnaryOp
static UnaryOp *	fromString (const std::string &definition)
	Creates a UnaryOp instance from given string definition. More...

static std::string	getFromStringSyntax (const std::string &opSpecifier)
	gives a string syntax description for given opSpecifier More...

static std::vector< std::string >	listFromStringOps ()
	returns a list of all supported OP_SPEC values for the fromString function More...

static void	applyFromString (const std::string &definition, const core::ImgBase src, core::ImgBase *dst)
	creates, applies and releases a UnaryOp defined by given definition string More...

Static Public Member Functions inherited from icl::utils::Configurable
static std::string	create_default_ID (const std::string &prefix)
	this function can be used in subclasses to create a default ID More...

static Configurable *	get (const std::string &id)
	returns configurable by given ID More...

static void	register_configurable_type (const std::string &classname, Function< Configurable * > creator)
	registers a configurable type More...

static std::vector< std::string >	get_registered_configurables ()
	returns a list of all registered configurable classnames More...

static Configurable *	create_configurable (const std::string &classname)
	creates a configurable by given name More...

Static Public Attributes inherited from icl::utils::Configurable
static const std::vector< std::string >	EMPTY_VEC
	used as shortcut – just an empty vector of std::strings More...

Protected Member Functions inherited from icl::filter::UnaryOp
bool	prepare (core::ImgBase **ppoDst, core::depth eDepth, const utils::Size &imgSize, core::format eFormat, int nChannels, const utils::Rect &roi, utils::Time timestamp=utils::Time::null)

virtual bool	prepare (core::ImgBase *ppoDst, const core::ImgBase poSrc)
	check+adapt destination image to properties of given source image More...

virtual bool	prepare (core::ImgBase *ppoDst, const core::ImgBase poSrc, core::depth eDepth)

Protected Member Functions inherited from icl::utils::Configurable
void	addProperty (const std::string &name, const std::string &type, const std::string &info, const Any &value=Any(), const int volatileness=0, const std::string &tooltip=std::string())
	This can be used by derived classes to store supported properties in the internal list. More...

void	addChildConfigurable (Configurable *configurable, const std::string &childPrefix="")
	This adds another configurable as child. More...

void	removeChildConfigurable (Configurable *configurable)
	removes the given child configurable More...

Property &	prop (const std::string &propertyName)
	this CAN be used e.g. to store a property value in internal property-list More...

const Property &	prop (const std::string &propertyName) const
	this CAN be used e.g. to store a property value in internal property-list More...

	Configurable (const std::string &ID="", bool ordered=true)
	create this configurable with given ID More...

void	call_callbacks (const std::string &propertyName, const Configurable *caller) const
	calls all registered callbacks More...

Protected Member Functions inherited from icl::utils::Uncopyable
	Uncopyable ()
	Empty base constructor. More...

Protected Attributes inherited from icl::filter::UnaryOp
utils::MultiThreader *	m_poMT

Protected Attributes inherited from icl::utils::Configurable
std::vector< Callback >	callbacks
	internally managed list of callbacks More...

Detailed Description

template<class T>
class icl::filter::LUTOp3Channel< T >

class for applying table look-up transformation to 3-channel integer-valued images

In many applications it is necessary to create a feature map on 3-channel input images. These feature map creation procedure can take much time, depending on the complexity of the calculated feature. In a very simple case for instance, the LUTOp3Channel can be used to create thresholded color-distance map using the the euclidean distance to a reference color and a threshold for each pixel of the source image. This operation can be applied on each input (r,g,b)-Tuple by the following function (which is basically implemented in the "'Plugin" structure nested in the LUTOp3Channel class:

virtual T transform(icl8u v1, icl8u v2, icl8u v3){
  return ::sqrt( ::pow(r-m_aiRGB[0],2) + ::pow(g-m_aiRGB[1],2) + ::pow(b-m_aiRGB[2],2) ) / (::sqrt(3.0)) < thresh ? 255 : 0;
}

This virtual function can be reimplemented by special plugins to calculate custom LUT-accelerated maps on icl8u/icl16s and icl32s -source images. The source images must be at least integer-typed, as the LUT, which is used internally has only discrete entries.
It is recommended to work with icl8u input images to avoid illegal memory access when using the LUT.

Implementing the Configurable Interface

The following procedure is used to create the LUT internally;

void create_lut(Plugin p, T lut[16777216]){
  for(int r = 0; r < 256; ++r){
    for(int g = 0; g < 256; ++g){
      for(int b = 0; b < 256; ++b){
        lut[r+ 256*g + 65536*b] = p.transform( r,g,b );
      }
    }
  }
}

When the LUT is created internally, it can be used for fast feature map calculation using a simple table look-up:

\#define CAST(x) Cast<srcT,icl8u>::cast(x)       
template<class srcT, class dstT>
void apply_lut_op_3(const Img<srcT> &src, Img<dstT> &dst, dstT *lut){
  const srcT * pSrcR = src.getData(0);
  const srcT * pSrcG = src.getData(1);
  const srcT * pSrcB = src.getData(2);
  dstT *pDst = dst.getData(0);
  dstT *pDstEnd = pDst+dst.getDim();
  while(pDst < pDstEnd){
    *pDst++  = lut[ CAST(*pSrcR++) + 256*CAST(*pSrcG++) + 65536*CAST(*pSrcB++) ];
  }
}

Performance

As it can be seen in section Implementing the Configurable Interface, each pixel is transformed by a simple table look up, which is performed by 2 multiplications, 2 additions and a simple dereferencing. The more complex part of this calculation is done by the calls to the Cast-class template. This is necessary to avoid index overruns due to the higher range of all non-icl8u input images types. The performance is much better, when using icl8u input images, because the Cast- call is left out in this case.

Benchmarks:

The default Plugins operation of threshold an implicitly created euclidean distance map takes about 18msec on an 640x480 3-channel icl8u input image. This can be accelerated by 61% to 11msec (1.6Mhz Pentium M) by using the LUTOp3Channel class. This benefit is not very high, but the euclidean distance function is only one possible function

$f:R^3~\rightarrow~R$

which can be implemented using the 3 channel lut. Consider, that all of these possibly very complex operations will not take more then the above measured 11msec.

Optimization "Shift"

In some applications, it is sufficient to use a decreased resolution for each channel range. E.g. if we use only 7Bit per channel, we can reduce the LUT size from $2^{24} \mbox{bytes} = 16.8\mbox{MB}$ to $2^{21} \mbox{bytes} = 2.1\mbox{MB}$ further reduction of the quantization level of each channel to 6Bit results in a $2^{18} \mbox{bytes}=262\mbox{kB}$ LUT.
The benefit of this optimization is at first of course the saving of a large part of necessary memory, but in a second view, it also increases processing speed even beyond the speed enhancement achieved using a LUT. The reason for the speed advantage compared with the full size LUT can be explained by the cpu's cache management: When using a 16.8MB data array which is nearly randomly accessed, the data can not be cached permanently, so the cache flow in influenced negatively. The following table illustrates some benchmark results using different bit shifts, compared on a 640x480 rgb icl8u image.

Shift	LUT size	Time*
0 (no shift)	16.8MB	11ms
1	2.2MB	8ms
2	262kB	4.3ms
3	33kB	3.5ms
4	4kB	3.5ms
5	512 Bytes	3.5ms
6	64 Bytes	3.5ms
7	8 Bytes	3.5ms

A bit shift value of 2 seems to be the best compromise between data resolution vs. speed and not at least memory usage. But note: There are some applications, where the data resolution can not be scaled down using bit shifts.

Constructor & Destructor Documentation

◆ LUTOp3Channel()

template<class T >

icl::filter::LUTOp3Channel< T >::LUTOp3Channel	(	Plugin *	p = `0`,
		icl8u	shift = `0`
	)

creates a LUT object with given lut (LUT-mode)

Parameters

p	plugin to use for the creation of the internal lut. Note:the LUTOp3Channel takes the ownership of the given plugin
shift	see Optimization "Shift"

◆ ~LUTOp3Channel()

template<class T >

virtual icl::filter::LUTOp3Channel< T >::~LUTOp3Channel ( )

virtual

Destructor.

Member Function Documentation

◆ apply() [1/3]

template<class T >

virtual void icl::filter::LUTOp3Channel< T >::apply	(	const core::ImgBase *	src,
		core::ImgBase **	dst
	)

virtual

Common Filter apply function using current mode.

Parameters

src	source image
dst	destination image**

Implements icl::filter::UnaryOp.

◆ apply() [2/3]

template<class T >

virtual const core::ImgBase* icl::filter::UnaryOp::apply

Import unaryOps apply function without destination image.

◆ apply() [3/3]

template<class T >

virtual void icl::filter::UnaryOp::apply

Import unaryOps apply function without destination image.

◆ removePlugin()

template<class T >

Plugin* icl::filter::LUTOp3Channel< T >::removePlugin ( )

inline

removes the internal plugin so it is not deleted with the LUTOp

◆ setPlugin()

template<class T >

void icl::filter::LUTOp3Channel< T >::setPlugin ( Plugin * p )

Sets a new plugin and re-calculates the internal LUT.

Parameters

p	plugin to use for the creation of the internal lut. Note:the LUTOp3Channel takes the ownership of the given plugin

Member Data Documentation

◆ m_oLUT

template<class T >

core::Img<T> icl::filter::LUTOp3Channel< T >::m_oLUT

private

Image that holds the lut data.

◆ m_poPlugin

template<class T >

Plugin* icl::filter::LUTOp3Channel< T >::m_poPlugin

private

Current plugin pointer.

◆ m_ucShift

template<class T >

icl8u icl::filter::LUTOp3Channel< T >::m_ucShift

private

channel range increment (...)

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

/Users/alneuman/vm/icl/ICLFilter/src/ICLFilter/LUTOp3Channel.h

Classes

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

template<class T> class icl::filter::LUTOp3Channel< T >

Implementing the Configurable Interface

Performance

Benchmarks:

Optimization "Shift"

Constructor & Destructor Documentation

◆ LUTOp3Channel()

◆ ~LUTOp3Channel()

Member Function Documentation

◆ apply() [1/3]

◆ apply() [2/3]

◆ apply() [3/3]

◆ removePlugin()

◆ setPlugin()

Member Data Documentation

◆ m_oLUT

◆ m_poPlugin

◆ m_ucShift

template<class T>
class icl::filter::LUTOp3Channel< T >