Class to compute an RGB colour histogram over an image or a rectangular portion of it. The histogram is normalized. We use the same number of bins for each of the channels (r,g,b). It is easy to extend this class so that it computes such histogram over a segment of a shape other than rectangular. More...

#include <i_color_histogram.h>

Inheritance diagram for kjb::Color_histogram:

Public Member Functions
	Color_histogram (unsigned int inum_bins=DEFAULT_COL_HIST_NUM_BINS)
	Constructor. Only memory for color histogram is allocated. More...

	Color_histogram (unsigned int inum_bins, const kjb::Image &img)
	Constructor. Color histogram for entire image is computed. More...

	Color_histogram (const char *fname)
	Constructor. Constructs a color histogram by reading it from a file. More...

	Color_histogram (std::istream &is)
	Constructor. Constructs a color histogram by reading it from an input stream. More...

	Color_histogram (unsigned int inum_bins, const Image &img, int top_left_x, int top_left_y, int bottom_right_x, int bottom_right_y)
	Constructor. Color histogram for the specified portion of the image is computed. More...

	Color_histogram (const Color_histogram &src)
	Copy constructor. More...

Color_histogram &	operator= (const Color_histogram &src)
	Assignment operator. More...

void	compute_histogram (const kjb::Image &img, unsigned int inum_bins, int top_left_x, int top_left_y, int bottom_right_x, int bottom_right_y)
	Computes a color histogram over the specified image region, and using the input number of bins. More...

void	compute_histogram (const kjb::Image &img, unsigned int inum_bins)
	Computes a color histogram over the entire image, and using the input number of bins. More...

void	compute_histogram (const kjb::Image &img)
	Computes a color histogram over the entire image, without changin the number of bins. More...

void	compute_histogram (const kjb::Image &img, int top_left_x, int top_left_y, int bottom_right_x, int bottom_right_y)
	Computes a color histogram over the specified image portion, without changin the number of bins. More...

unsigned int	get_num_bins () const
	Returns the number of bins. More...

double	get_value (float r, float g, float b) const
	Returns the value of the bin corresponding to the input (r,g,b) values. More...

double	get_value (int ibin_number) const

void	print_human_readable (std::ostream &out) const

double	compare (const Color_histogram &ch) const

double	sum () const
	compute sum of all the bins in the histogram More...

virtual void	read (std::istream &in)
	Reads this camera from an input stream. More...

virtual void	read (const char *fname)
	Reads this parametric_parapiped from a file. More...

virtual void	write (std::ostream &out) const
	Writes this camera to an output stream. More...

virtual void	write (const char *fname) const
	Writes this camera to an output stream. More...

Public Member Functions inherited from kjb::Readable
virtual	~Readable ()
	Deletes this Readable. More...

Public Member Functions inherited from kjb::Writeable
virtual	~Writeable ()
	Deletes this Writeable. More...

Additional Inherited Members
Static Public Member Functions inherited from kjb::Readable
static const char *	read_field_value (std::istream &in, const char field_name, char field_buf, size_t buf_len, char separator=':')
	Reads a line off in into a buffer and returns a pointer to the field value in the buffer. More...

static const char *	read_field_value (std::istream &in, const char *field_name, char separator=':')
	Reads a line off in into an internal buffer and returns a pointer to the field value in the buffer. More...

Detailed Description

Class to compute an RGB colour histogram over an image or a rectangular portion of it. The histogram is normalized. We use the same number of bins for each of the channels (r,g,b). It is easy to extend this class so that it computes such histogram over a segment of a shape other than rectangular.

Constructor & Destructor Documentation

Color_histogram::Color_histogram ( unsigned int inum_bins = DEFAULT_COL_HIST_NUM_BINS )

Constructor. Only memory for color histogram is allocated.

Constructor. This constructor only initializes the memory for the histogram

Parameters

num_bins the number of bins in the histogram. This value is used to discretize each of the channels (r,g,b)

Color_histogram::Color_histogram	(	unsigned int	inum_bins,
		const kjb::Image &	img
	)

Constructor. Color histogram for entire image is computed.

Constructor. The color histogram is computed over the entire image

Parameters

num_bins	the number of bins in the histogram. This value is used to discretize each of the channels (r,g,b)
img	the image to compute the histogram over

kjb::Color_histogram::Color_histogram ( const char * fname )

inline

Constructor. Constructs a color histogram by reading it from a file.

kjb::Color_histogram::Color_histogram ( std::istream & is )

inline

Constructor. Constructs a color histogram by reading it from an input stream.

Color_histogram::Color_histogram	(	unsigned int	inum_bins,
		const Image &	img,
		int	top_left_x,
		int	top_left_y,
		int	bottom_right_x,
		int	bottom_right_y
	)

Constructor. Color histogram for the specified portion of the image is computed.

Constructor. The color histogram is computed over the specified rectangular portion of the image

Parameters

num_bins	the number of bins in the histogram. This value is used to discretize each of the channels (r,g,b)
img	the image to compute the histogram over
top_left_x	The top left x coordinate of the rectangular portion of the image to compute the histogram over. The origin of the image system is the top left corner of the image, with x increasing left to right, y increasing top to bottom
top_left_y	The top left y coordinate of the rectangle
bottom_right_x	The bottom right x coordinate of the rectangle
bottom_right_y	The bottom right y coordinate of the rectangle

Color_histogram::Color_histogram ( const Color_histogram & src )

Copy constructor.

Copy constructor

Parameters

src	The Color_histogram to copy into this one

Member Function Documentation

double Color_histogram::compare ( const Color_histogram & ch ) const

void Color_histogram::compute_histogram	(	const kjb::Image &	img,
		unsigned int	inum_bins,
		int	top_left_x,
		int	top_left_y,
		int	bottom_right_x,
		int	bottom_right_y
	)

Computes a color histogram over the specified image region, and using the input number of bins.

void Color_histogram::compute_histogram	(	const kjb::Image &	img,
		unsigned int	inum_bins
	)

Computes a color histogram over the entire image, and using the input number of bins.

void Color_histogram::compute_histogram ( const kjb::Image & img )

Computes a color histogram over the entire image, without changin the number of bins.

void Color_histogram::compute_histogram	(	const kjb::Image &	img,
		int	top_left_x,
		int	top_left_y,
		int	bottom_right_x,
		int	bottom_right_y
	)

Computes a color histogram over the specified image portion, without changin the number of bins.

unsigned int kjb::Color_histogram::get_num_bins ( ) const

inline

Returns the number of bins.

double kjb::Color_histogram::get_value	(	float	r,
		float	g,
		float	b
	)		const

inline

Returns the value of the bin corresponding to the input (r,g,b) values.

double kjb::Color_histogram::get_value ( int ibin_number ) const

inline

Color_histogram & Color_histogram::operator= ( const Color_histogram & src )

Assignment operator.

Assignment operator

Parameters

src	The Color_histogram to assign to this one

void Color_histogram::print_human_readable ( std::ostream & out ) const

void Color_histogram::read ( std::istream & in )

virtual

Reads this camera from an input stream.

Implements kjb::Readable.

virtual void kjb::Color_histogram::read ( const char * fname )

inlinevirtual

Reads this parametric_parapiped from a file.

Reimplemented from kjb::Readable.

double kjb::Color_histogram::sum ( ) const

inline

compute sum of all the bins in the histogram

void Color_histogram::write ( std::ostream & out ) const

virtual

Writes this camera to an output stream.

Implements kjb::Writeable.

virtual void kjb::Color_histogram::write ( const char * fname ) const

inlinevirtual

Writes this camera to an output stream.

Reimplemented from kjb::Writeable.

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

/work/kobus/src/lib/i_cpp/i_color_histogram.h
/work/kobus/src/lib/i_cpp/i_color_histogram.cpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation