binarizer.c File Reference

Binarize the image. More...

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "jabcode.h"

Macros
#define	BLOCK_SIZE_POWER   3
#define	BLOCK_SIZE   (1 << BLOCK_SIZE_POWER)
#define	BLOCK_SIZE_MASK   (BLOCK_SIZE - 1)
#define	MINIMUM_DIMENSION   (BLOCK_SIZE * 5)
#define	CAP(val, min, max)   (val < min ? min : (val > max ? max : val))

Functions
jab_boolean	isBiTrimodal (jab_float hist[], jab_int32 channel)
	Check bimodal/trimodal distribution. More...
jab_int32	getMinimumThreshold (jab_int32 hist[], jab_int32 channel)
	Get the minimal value in a histogram with bimodal distribution. More...
jab_bitmap *	binarizerHist (jab_bitmap *bitmap, jab_int32 channel)
	Binarize a color channel of a bitmap using histogram binarization algorithm. More...
jab_bitmap *	binarizerHard (jab_bitmap *bitmap, jab_int32 channel, jab_int32 threshold)
	Binarize a color channel of a bitmap using a given threshold. More...
void	getBinaryBitmap (jab_bitmap *bitmap, jab_int32 channel, jab_int32 sub_width, jab_int32 sub_height, jab_byte *black_points, jab_bitmap *binary)
	Do local binarization based on the black points. More...
void	calculateBlackPoints (jab_bitmap *bitmap, jab_int32 channel, jab_int32 sub_width, jab_int32 sub_height, jab_byte *black_points)
	Calculate the black point of each block. More...
void	filterBinary (jab_bitmap *binary)
	Filter out noises in binary bitmap. More...
jab_bitmap *	binarizer (jab_bitmap *bitmap, jab_int32 channel)
	Binarize a color channel of a bitmap using local binarization algorithm. More...

Detailed Description

Binarize the image.

libjabcode - JABCode Encoding/Decoding Library

Copyright 2016 by Fraunhofer SIT. All rights reserved. See LICENSE file for full terms of use and distribution.

Contact: Huajian Liu liu@s.nosp@m.it.f.nosp@m.raunh.nosp@m.ofer.nosp@m..de Waldemar Berchtold walde.nosp@m.mar..nosp@m.berch.nosp@m.told.nosp@m.@sit..nosp@m.frau.nosp@m.nhofe.nosp@m.r.de

Function Documentation

jab_bitmap* binarizer	(	jab_bitmap *	bitmap,
		jab_int32	channel
	)

Binarize a color channel of a bitmap using local binarization algorithm.

Parameters

bitmap	the input bitmap
channel	the color channel

Returns

binarized bitmap | NULL if failed

jab_bitmap* binarizerHard	(	jab_bitmap *	bitmap,
		jab_int32	channel,
		jab_int32	threshold
	)

Binarize a color channel of a bitmap using a given threshold.

Parameters

bitmap	the input bitmap
channel	the color channel
threshold	the threshold

Returns

binarized bitmap | NULL if failed

jab_bitmap* binarizerHist	(	jab_bitmap *	bitmap,
		jab_int32	channel
	)

Binarize a color channel of a bitmap using histogram binarization algorithm.

Parameters

bitmap	the input bitmap
channel	the color channel

Returns

binarized bitmap | NULL if failed

void calculateBlackPoints	(	jab_bitmap *	bitmap,
		jab_int32	channel,
		jab_int32	sub_width,
		jab_int32	sub_height,
		jab_byte *	black_points
	)

Calculate the black point of each block.

Parameters

bitmap	the input bitmap
channel	the color channel
sub_width	the number of blocks in x direction
sub_height	the number of blocks in y direction
black_points	the black points

void filterBinary

(

jab_bitmap *

binary

)

Filter out noises in binary bitmap.

Parameters

binary

the binarized bitmap

void getBinaryBitmap	(	jab_bitmap *	bitmap,
		jab_int32	channel,
		jab_int32	sub_width,
		jab_int32	sub_height,
		jab_byte *	black_points,
		jab_bitmap *	binary
	)

Do local binarization based on the black points.

Parameters

bitmap	the input bitmap
channel	the color channel
sub_width	the number of blocks in x direction
sub_height	the number of blocks in y direction
black_points	the black points
binary	the binarized bitmap

jab_int32 getMinimumThreshold	(	jab_int32	hist[],
		jab_int32	channel
	)

Get the minimal value in a histogram with bimodal distribution.

Parameters

hist	the histogram
channel	the color channel

Returns

minimum threshold | -1 if failed

jab_boolean isBiTrimodal	(	jab_float	hist[],
		jab_int32	channel
	)

Check bimodal/trimodal distribution.

Parameters

hist	the histogram
channel	the color channel

Returns

JAB_SUCCESS | JAB_FAILURE