Extracts mean-normalized intensity patch around a pixel. More...

#include <intensity_descriptor.hpp>

Public Member Functions
const int *	getDescriptorIndexOffsets () const
int	getDescriptorLength () const
int	getDescriptorStride () const
	IntensityDescriptorExtractor (int raw_gray_stride, int feature_window_size)
void	populateDescriptorAligned (uint8_t image, int x, int y, uint8_t descriptor) const
void	populateDescriptorInterp (uint8_t image, float x, float y, uint8_t descriptor) const
void	populateDescriptorsAligned (uint8_t image, const KeypointData keypoints, int num_keypoints, uint8_t *descriptors) const
void	populateDescriptorsInterp (uint8_t image, const KeypointData keypoints, int num_keypoints, uint8_t *descriptors) const
virtual	~IntensityDescriptorExtractor ()
Private Member Functions
void	initialize ()
	IntensityDescriptorExtractor (const IntensityDescriptorExtractor &other)
void	normalizeDescriptor (uint8_t *desc) const
IntensityDescriptorExtractor &	operator= (const IntensityDescriptorExtractor &other)
Private Attributes
int	_brightess_offset_num_sse_ops
uint8_t *	_descriptor_brightness_offset
int *	_descriptor_index_offsets
int	_descriptor_len
int	_descriptor_stride
int	_feature_window_size
int	_num_descriptor_pad_bytes
int	_raw_gray_stride

Detailed Description

Extracts mean-normalized intensity patch around a pixel.

Definition at line 17 of file intensity_descriptor.hpp.

Constructor & Destructor Documentation

fovis::IntensityDescriptorExtractor::IntensityDescriptorExtractor	(	int	raw_gray_stride,
		int	feature_window_size
	)		`[inline]`

Parameters:

raw_gray_stride	specifies the number of bytes separating each row of the input image.
feature_window_size	the size of the descriptor window.

Definition at line 24 of file intensity_descriptor.hpp.

virtual fovis::IntensityDescriptorExtractor::~IntensityDescriptorExtractor ( ) [inline, virtual]

Definition at line 30 of file intensity_descriptor.hpp.

fovis::IntensityDescriptorExtractor::IntensityDescriptorExtractor ( const IntensityDescriptorExtractor & other ) [private]

Member Function Documentation

const int* fovis::IntensityDescriptorExtractor::getDescriptorIndexOffsets ( ) const [inline]

Returns:: an array of offset indices indicating the image offset of each descriptor pixel from the descriptor center pixel.

Definition at line 95 of file intensity_descriptor.hpp.

int fovis::IntensityDescriptorExtractor::getDescriptorLength ( ) const [inline]

Returns:: the number of useful bytes in each descriptor.

Definition at line 102 of file intensity_descriptor.hpp.

int fovis::IntensityDescriptorExtractor::getDescriptorStride ( ) const [inline]

Returns:: the number of bytes that should separate descriptors in a vector of keypoint descriptors. This is usually a multiple of 16 so that each descriptor is 16-byte aligned.

Definition at line 87 of file intensity_descriptor.hpp.

void fovis::IntensityDescriptorExtractor::initialize ( ) [private]

Definition at line 26 of file intensity_descriptor.cpp.

void fovis::IntensityDescriptorExtractor::normalizeDescriptor ( uint8_t * desc ) const [private]

Definition at line 111 of file intensity_descriptor.cpp.

IntensityDescriptorExtractor& fovis::IntensityDescriptorExtractor::operator= ( const IntensityDescriptorExtractor & other ) [private]

void fovis::IntensityDescriptorExtractor::populateDescriptorAligned	(	uint8_t *	image,
		int	x,
		int	y,
		uint8_t *	descriptor
	)		const

Computes a single descriptor. Assumes that the output parameter descriptor is 16-byte aligned.

Definition at line 92 of file intensity_descriptor.cpp.

void fovis::IntensityDescriptorExtractor::populateDescriptorInterp	(	uint8_t *	image,
		float	x,
		float	y,
		uint8_t *	descriptor
	)		const

Computes a single descriptor using bilinear interpolation at every point on the descriptor. This performs 4 floating point multiplications for every pixel in the descriptor.

Assumes that the output parameter is 16-byte aligned.

Definition at line 61 of file intensity_descriptor.cpp.

void fovis::IntensityDescriptorExtractor::populateDescriptorsAligned	(	uint8_t *	image,
		const KeypointData *	keypoints,
		int	num_keypoints,
		uint8_t *	descriptors
	)		const

Compute many descriptors.

Parameters:

image	input image used for descriptor computation.
keypoints	keypoints for descriptor computation.
num_keypoints	the number of keypoints.
descriptors	Must be 16-byte aligned and pre-allocated to `num_keypoints` * 16 * getDescriptorStride() bytes.

Definition at line 158 of file intensity_descriptor.cpp.

void fovis::IntensityDescriptorExtractor::populateDescriptorsInterp	(	uint8_t *	image,
		const KeypointData *	keypoints,
		int	num_keypoints,
		uint8_t *	descriptors
	)		const

Compute many descriptors using bilinear interpolation.

Parameters:

image	input image used for descriptor computation.
keypoints	keypoints for descriptor computation.
num_keypoints	the number of keypoints.
descriptors	Must be 16-byte aligned and pre-allocated to `num_keypoints` * 16 * getDescriptorStride() bytes.