CChi2Kernel Class Reference

Inheritance diagram for CChi2Kernel:

List of all members.

Public Member Functions

CChi2Kernel (int32_t size, float64_t width)

CChi2Kernel (CRealFeatures *l, CRealFeatures *r, float64_t width, int32_t size)

virtual ~CChi2Kernel ()

virtual bool init (CFeatures *l, CFeatures *r)

virtual bool load_init (FILE *src)

virtual bool save_init (FILE *dest)

virtual EKernelType get_kernel_type ()

virtual const char * get_name ()

Protected Member Functions

virtual float64_t compute (int32_t idx_a, int32_t idx_b)

Protected Attributes

float64_t width

Detailed Description

The Chi2 kernel operating on realvalued vectors computes the chi-squared distance between sets of histograms. It is a very useful distance in image recognition (used to detect objects).

It is defined as

$k({\bf x},({\bf x'})= e^{-\frac{1}{width} \sum_{i=0}^{l}\frac{(x_i-x'_i)^2}{(x_i+x'_i)}}$

Definition at line 29 of file Chi2Kernel.h.

Constructor & Destructor Documentation

CChi2Kernel::CChi2Kernel	(	int32_t	size,
		float64_t	width
	)

constructor

Parameters:

	size	cache size
	width	width

Definition at line 17 of file Chi2Kernel.cpp.

CChi2Kernel::CChi2Kernel	(	CRealFeatures *	l,
		CRealFeatures *	r,
		float64_t	width,
		int32_t	size
	)

constructor

Parameters:

	l	features of left-hand side
	r	features of right-hand side
	width	width
	size	cache size

Definition at line 22 of file Chi2Kernel.cpp.

CChi2Kernel::~CChi2Kernel ( ) [virtual]

Definition at line 29 of file Chi2Kernel.cpp.

Member Function Documentation

float64_t CChi2Kernel::compute	(	int32_t	idx_a,
		int32_t	idx_b
	)			`[protected, virtual]`

compute kernel function for features a and b idx_{a,b} denote the index of the feature vectors in the corresponding feature object

Parameters:

	idx_a	index a
	idx_b	index b

Returns:: computed kernel function at indices a,b

Implements CKernel.

Definition at line 51 of file Chi2Kernel.cpp.

virtual EKernelType CChi2Kernel::get_kernel_type ( ) [virtual]

return what type of kernel we are

Returns:: kernel type CHI2

Implements CKernel.

Definition at line 77 of file Chi2Kernel.h.

virtual const char* CChi2Kernel::get_name ( ) [virtual]

return the kernel's name

Returns:: name Chi2

Implements CKernel.

Definition at line 83 of file Chi2Kernel.h.

bool CChi2Kernel::init	(	CFeatures *	l,
		CFeatures *	r
	)			`[virtual]`

initialize kernel

Parameters:

	l	features of left-hand side
	r	features of right-hand side

Returns:: if initializing was successful

Reimplemented from CSimpleKernel< float64_t >.

Definition at line 34 of file Chi2Kernel.cpp.

bool CChi2Kernel::load_init ( FILE * src ) [virtual]

load kernel init_data

Parameters:

src

file to load from

Returns:: if loading was successful

Implements CKernel.

Definition at line 41 of file Chi2Kernel.cpp.

bool CChi2Kernel::save_init ( FILE * dest ) [virtual]

save kernel init_data

Parameters:

dest

file to save to

Returns:: if saving was successful

Implements CKernel.

Definition at line 46 of file Chi2Kernel.cpp.

Member Data Documentation

float64_t CChi2Kernel::width [protected]

width

Definition at line 98 of file Chi2Kernel.h.

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


Public Member Functions
	CChi2Kernel (int32_t size, float64_t width)
	CChi2Kernel (CRealFeatures l, CRealFeatures r, float64_t width, int32_t size)
virtual	~CChi2Kernel ()
virtual bool	init (CFeatures l, CFeatures r)
virtual bool	load_init (FILE *src)
virtual bool	save_init (FILE *dest)
virtual EKernelType	get_kernel_type ()
virtual const char *	get_name ()
Protected Member Functions
virtual float64_t	compute (int32_t idx_a, int32_t idx_b)
Protected Attributes
float64_t	width