libdemosaicking.cpp File Reference

Demosaicking functions: HAmilton-Adams algorithm, NLmeans based demosaicking, Chromatic components filtering. More...

#include "libdemosaicking.h"

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Defines
#define	GREENPOSITION   0
#define	REDPOSITION   1
#define	BLUEPOSITION   2
Functions
void	demosaicking_adams (float threshold, int redx, int redy, float *ired, float *igreen, float *iblue, float *ored, float *ogreen, float *oblue, int width, int height)
	Classical Adams-Hamilton demosaicking algorithm.
void	demosaicking_bilinear_red_blue (int redx, int redy, float *ored, float *ogreen, float *oblue, int width, int height)
	Classical bilinear interpolation of red and blue differences with the green channel.
void	demosaicking_nlmeans (int bloc, float h, int redx, int redy, float *ired, float *igreen, float *iblue, float *ored, float *ogreen, float *oblue, int width, int height)
	NLmeans based demosaicking.
void	chromatic_median (int iter, int redx, int redy, int projflag, float side, float *ired, float *igreen, float *iblue, float *ored, float *ogreen, float *oblue, int width, int height)
	Iterate median filter on chromatic components of the image.
void	ssd_demosaicking_chain (int redx, int redy, float *ired, float *igreen, float *iblue, float *ored, float *ogreen, float *oblue, int width, int height)
	Demosaicking chain.

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Detailed Description

Demosaicking functions: HAmilton-Adams algorithm, NLmeans based demosaicking, Chromatic components filtering.

Author:

Antoni Buades <toni.buades@uib.es>

Definition in file libdemosaicking.cpp.

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Define Documentation

#define BLUEPOSITION   2

Definition at line 51 of file libdemosaicking.cpp.

#define GREENPOSITION   0

Definition at line 49 of file libdemosaicking.cpp.

#define REDPOSITION   1

Definition at line 50 of file libdemosaicking.cpp.

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Function Documentation

void chromatic_median	(	int	iter,
		int	redx,
		int	redy,
		int	projflag,
		float	side,
		float *	ired,
		float *	igreen,
		float *	iblue,
		float *	ored,
		float *	ogreen,
		float *	oblue,
		int	width,
		int	height
	)

Iterate median filter on chromatic components of the image.

Parameters:

[in]	ired,igreen,iblue	initial image
[in]	iter	number of iteracions
[out]	ored,ogreen,oblue	filtered output
[in]	(redx,redy)	coordinates of the red pixel: (0,0), (0,1), (1,0), (1,1)
[in]	side	median in a (2*side+1) x (2*side+1) window
[in]	projflag	if not zero, values of the original CFA are kept
[in]	width,height	size of the image

Definition at line 482 of file libdemosaicking.cpp.

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void demosaicking_adams	(	float	threshold,
		int	redx,
		int	redy,
		float *	ired,
		float *	igreen,
		float *	iblue,
		float *	ored,
		float *	ogreen,
		float *	oblue,
		int	width,
		int	height
	)

Classical Adams-Hamilton demosaicking algorithm.

The green channel is interpolated directionally depending on the green first and red and blue second directional derivatives. The red and blue differences with the green channel are interpolated bilinearly.

Parameters:

[in]	ired,igreen,iblue	original cfa image
[out]	ored,ogreen,oblue	demosaicked output
[in]	(redx,redy)	coordinates of the red pixel: (0,0), (0,1), (1,0), (1,1)
[in]	threshold	value to consider horizontal and vertical variations equivalent and average both estimates
[in]	width,height	size of the image

Definition at line 84 of file libdemosaicking.cpp.

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void demosaicking_bilinear_red_blue	(	int	redx,
		int	redy,
		float *	ored,
		float *	ogreen,
		float *	oblue,
		int	width,
		int	height
	)

Classical bilinear interpolation of red and blue differences with the green channel.

Parameters:

[in]	ored,ogreen,oblue	original cfa image with green interpolated
[out]	ored,ogreen,oblue	demosaicked output
[in]	(redx,redy)	coordinates of the red pixel: (0,0), (0,1), (1,0), (1,1)
[in]	width,height	size of the image

Definition at line 210 of file libdemosaicking.cpp.

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void demosaicking_nlmeans	(	int	bloc,
		float	h,
		int	redx,
		int	redy,
		float *	ired,
		float *	igreen,
		float *	iblue,
		float *	ored,
		float *	ogreen,
		float *	oblue,
		int	width,
		int	height
	)

NLmeans based demosaicking.

For each value to be filled, a weigthed average of original CFA values of the same channel is performed. The weight depends on the difference of a 3x3 color patch

Parameters:

[in]	ired,igreen,iblue	initial demosaicked image
[out]	ored,ogreen,oblue	demosaicked output
[in]	(redx,redy)	coordinates of the red pixel: (0,0), (0,1), (1,0), (1,1)
[in]	bloc	research block of size (2+bloc+1) x (2*bloc+1)
[in]	h	kernel bandwidth
[in]	width,height	size of the image

Definition at line 330 of file libdemosaicking.cpp.

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void ssd_demosaicking_chain	(	int	redx,
		int	redy,
		float *	ired,
		float *	igreen,
		float *	iblue,
		float *	ored,
		float *	ogreen,
		float *	oblue,
		int	width,
		int	height
	)

Demosaicking chain.

Compute initialization by Adams-Hamilton algorithm (u0)

for h in {16,4,1} do {

u <- NL_h(u0); Apply NLmeans demosaicking

u <- CR(u); Apply chromatic regularization

u0 <- u;

}

Output <- u;

Parameters:

[in]	ired,igreen,iblue	initial image
[out]	ored,ogreen,oblue	filtered output
[in]	(redx,redy)	coordinates of the red pixel: (0,0), (0,1), (1,0), (1,1)
[in]	width,height	size of the image

Definition at line 586 of file libdemosaicking.cpp.

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