colorbalance_lib.c File Reference

color balance algorithms More...

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <float.h>
#include "balance_lib.h"
#include "colorbalance_lib.h"

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Defines
#define	MAX(A, B)   (((A) >= (B)) ? (A) : (B))
	max of A and B
#define	MAX3(A, B, C)   (((A) >= (B)) ? MAX(A,C) : MAX(B,C))
	max of A, B, and C
Functions
unsigned char *	colorbalance_rgb_u8 (unsigned char *rgb, size_t size, size_t nb_min, size_t nb_max)
	simplest color balance on RGB channels
float *	colorbalance_irgb_f32 (float *rgb, size_t size, size_t nb_min, size_t nb_max)
	simplest color balance based on the I axis applied to the RGB channels, bounded

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Detailed Description

color balance algorithms

Author:

Nicolas Limare <nicolas.limare@cmla.ens-cachan.fr>

Jose-Luis Lisani <joseluis.lisani@uib.es>

Catalina Sbert <catalina.sbert@uib.es>

Todo:

check precision loss, maybe use double precision values

Definition in file colorbalance_lib.c.

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Define Documentation

#define MAX	(		A,
			B
	)			(((A) >= (B)) ? (A) : (B))

max of A and B

Definition at line 56 of file colorbalance_lib.c.

#define MAX3	(		A,
			B,
			C
	)			(((A) >= (B)) ? MAX(A,C) : MAX(B,C))

max of A, B, and C

Definition at line 59 of file colorbalance_lib.c.

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Function Documentation

float* colorbalance_irgb_f32	(	float *	rgb,
		size_t	size,
		size_t	nb_min,
		size_t	nb_max
	)

simplest color balance based on the I axis applied to the RGB channels, bounded

The input image is normalized by affine transformation on the I axis, saturating a percentage of the pixels at the beginning and end of the axis. This transformation is linearly applied to the R, G and B channels. The RGB cube is not stable by this operation, so some projections towards (0,0,0) on the RGB cube will be performed if needed.

Todo:

compute I=R+G+B instead of (R+G+B)/3 to save a division

Definition at line 72 of file colorbalance_lib.c.

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unsigned char* colorbalance_rgb_u8	(	unsigned char *	rgb,
		size_t	size,
		size_t	nb_min,
		size_t	nb_max
	)

simplest color balance on RGB channels

The input image is normalized by affine transformation on each RGB channel, saturating a percentage of the pixels at the beginning and end of the color space on each channel.

Definition at line 46 of file colorbalance_lib.c.

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