Gray-world white balance algorithm. More...

#include <opencv2/xphoto/white_balance.hpp>

Collaboration diagram for cv::xphoto::GrayworldWB:

Public Member Functions
virtual float	getSaturationThreshold () const =0
	Maximum saturation for a pixel to be included in the gray-world assumption.

virtual void	setSaturationThreshold (float val)=0
	Maximum saturation for a pixel to be included in the gray-world assumption.

Public Member Functions inherited from cv::xphoto::WhiteBalancer
virtual void	balanceWhite (InputArray src, OutputArray dst)=0
	Applies white balancing to the input image.

Public Member Functions inherited from cv::Algorithm
	Algorithm ()

virtual	~Algorithm ()

virtual void	clear ()
	Clears the algorithm state.

virtual bool	empty () const
	Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read.

virtual String	getDefaultName () const

virtual void	read (const FileNode &fn)
	Reads algorithm parameters from a file storage.

virtual void	save (const String &filename) const

void	write (const Ptr< FileStorage > &fs, const String &name=String()) const

virtual void	write (FileStorage &fs) const
	Stores algorithm parameters in a file storage.

void	write (FileStorage &fs, const String &name) const

Additional Inherited Members
Static Public Member Functions inherited from cv::Algorithm
template<typename _Tp >
static Ptr< _Tp >	load (const String &filename, const String &objname=String())
	Loads algorithm from the file.

template<typename _Tp >
static Ptr< _Tp >	loadFromString (const String &strModel, const String &objname=String())
	Loads algorithm from a String.

template<typename _Tp >
static Ptr< _Tp >	read (const FileNode &fn)
	Reads algorithm from the file node.

Protected Member Functions inherited from cv::Algorithm
void	writeFormat (FileStorage &fs) const

Detailed Description

Gray-world white balance algorithm.

This algorithm scales the values of pixels based on a gray-world assumption which states that the average of all channels should result in a gray image.

It adds a modification which thresholds pixels based on their saturation value and only uses pixels below the provided threshold in finding average pixel values.

Saturation is calculated using the following for a 3-channel RGB image per pixel I and is in the range [0, 1]:

\[ \texttt{Saturation} [I] = \frac{\textrm{max}(R,G,B) - \textrm{min}(R,G,B) }{\textrm{max}(R,G,B)} \]

A threshold of 1 means that all pixels are used to white-balance, while a threshold of 0 means no pixels are used. Lower thresholds are useful in white-balancing saturated images.

Currently supports images of type CV_8UC3 and CV_16UC3.