decoder.c File Reference

Data decoding. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "jabcode.h"
#include "detector.h"
#include "decoder.h"
#include "ldpc.h"
#include "encoder.h"

Functions
void	copyAndInterpolateSubblockFrom16To32 (jab_byte *palette, jab_int32 dst_offset, jab_int32 src_offset)
	Copy 16-color sub-blocks of 64-color palette into 32-color blocks of 256-color palette and interpolate into 32 colors. More...
void	interpolatePalette (jab_byte *palette, jab_int32 color_number)
	Interpolate 64-color palette into 128-/256-color palette. More...
jab_int32	readColorPaletteInMaster (jab_bitmap *matrix, jab_decoded_symbol *symbol, jab_byte *data_map, jab_int32 *module_count, jab_int32 *x, jab_int32 *y)
	Read the color palettes in master symbol. More...
jab_int32	readColorPaletteInSlave (jab_bitmap *matrix, jab_decoded_symbol *symbol, jab_byte *data_map)
	Read the color palettes in master symbol. More...
jab_byte	decodeModuleHD (jab_byte *palette, jab_int32 color_number, jab_byte r, jab_byte g, jab_byte b)
	Decode a module using hard decision. More...
jab_byte	decodeModule (jab_byte *palette, jab_int32 color_number, jab_float *ths, jab_float *rp, jab_byte *rgb, jab_float *p)
	Decode a module using soft decision. More...
jab_boolean	getPaletteThreshold (jab_byte *palette, jab_int32 color_number, jab_float **palette_ths, jab_float **palette_rp)
	Get the pixel value thresholds and reference points for each channel of the colors in the palette. More...
void	getNextMetadataModuleInMaster (jab_int32 matrix_height, jab_int32 matrix_width, jab_int32 next_module_count, jab_int32 *x, jab_int32 *y)
	Get the coordinate of the next metadata module in master symbol. More...
jab_int32	decodeSlaveMetadata (jab_decoded_symbol *host_symbol, jab_int32 docked_position, jab_data *data, jab_int32 offset)
	Decode slave symbol metadata. More...
jab_int32	decodeMasterMetadata (jab_bitmap *matrix, jab_decoded_symbol *symbol, jab_byte *data_map)
	Decode master symbol metadata. More...
jab_data *	readRawModuleData (jab_bitmap *matrix, jab_decoded_symbol *symbol, jab_byte *data_map, jab_float **bits_p)
	Decode data modules. More...
jab_data *	rawModuleData2RawData (jab_data *raw_module_data, jab_int32 bits_per_module)
	Convert multi-bit-per-byte raw module data to one-bit-per-byte raw data. More...
void	fillDataMap (jab_byte *data_map, jab_int32 width, jab_int32 height, jab_int32 type)
	Mark the positions of finder patterns and alignment patterns in the data map. More...
jab_int32	loadDefaultMasterMetadata (jab_bitmap *matrix, jab_decoded_symbol *symbol, jab_byte *data_map)
	Load default metadata values and color palettes for master symbol. More...
jab_int32	decodeSymbol (jab_bitmap *matrix, jab_decoded_symbol *symbol, jab_byte *data_map, jab_int32 type)
	Decode symbol. More...
jab_int32	decodeMaster (jab_bitmap *matrix, jab_decoded_symbol *symbol)
	Decode master symbol. More...
jab_int32	decodeSlave (jab_bitmap *matrix, jab_decoded_symbol *symbol)
	Decode slave symbol. More...
jab_int32	readData (jab_data *data, jab_int32 start, jab_int32 length, jab_int32 *value)
	Read bit data. More...
jab_data *	decodeData (jab_data *bits)
	Interpret decoded bits. More...

Detailed Description

Data decoding.

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

void copyAndInterpolateSubblockFrom16To32	(	jab_byte *	palette,
		jab_int32	dst_offset,
		jab_int32	src_offset
	)

Copy 16-color sub-blocks of 64-color palette into 32-color blocks of 256-color palette and interpolate into 32 colors.

Parameters

palette	the color palette
dst_offset	the start offset in the destination palette
src_offset	the start offset in the source palette

jab_data* decodeData

(

jab_data *

bits

)

Interpret decoded bits.

Parameters

bits	the input bits

Returns

the data message

jab_int32 decodeMaster	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol
	)

Decode master symbol.

Parameters

matrix	the symbol matrix
symbol	the master symbol

Returns

JAB_SUCCESS | JAB_FAILURE | FATAL_ERROR

jab_int32 decodeMasterMetadata	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol,
		jab_byte *	data_map
	)

Decode master symbol metadata.

Parameters

matrix	the symbol matrix
symbol	the master symbol
data_map	the data module positions

Returns

JAB_SUCCESS | JAB_FAILURE | DECODE_METADATA_FAILED | FATAL_ERROR

jab_byte decodeModule	(	jab_byte *	palette,
		jab_int32	color_number,
		jab_float *	ths,
		jab_float *	rp,
		jab_byte *	rgb,
		jab_float *	p
	)

Decode a module using soft decision.

Parameters

palette	the color palette
color_number	the number of colors
ths	the pixel value thresholds
rp	the reference pixel values
rgb	the pixel value in RGB format
p	the probability of the reliability of the decoded bits

Returns

the decoded value

jab_byte decodeModuleHD	(	jab_byte *	palette,
		jab_int32	color_number,
		jab_byte	r,
		jab_byte	g,
		jab_byte	b
	)

Decode a module using hard decision.

Parameters

palette	the color palette
color_number	the number of colors
r	the red channel value
g	the green channel value
b	the blue channel value

Returns

the decoded value

jab_int32 decodeSlave	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol
	)

Decode slave symbol.

Parameters

matrix	the symbol matrix
symbol	the slave symbol

Returns

JAB_SUCCESS | JAB_FAILURE | FATAL_ERROR

jab_int32 decodeSlaveMetadata	(	jab_decoded_symbol *	host_symbol,
		jab_int32	docked_position,
		jab_data *	data,
		jab_int32	offset
	)

Decode slave symbol metadata.

Parameters

host_symbol	the host symbol
docked_position	the docked position
data	the data stream of the host symbol
offset	the metadata start offset in the data stream

Returns

the read metadata bit length | DECODE_METADATA_FAILED

jab_int32 decodeSymbol	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol,
		jab_byte *	data_map,
		jab_int32	type
	)

Decode symbol.

Parameters

matrix	the symbol matrix
symbol	the symbol to be decoded
data_map	the data module positions
type	the symbol type, 0: master, 1: slave

Returns

JAB_SUCCESS | JAB_FAILURE | DECODE_METADATA_FAILED | FATAL_ERROR

void fillDataMap	(	jab_byte *	data_map,
		jab_int32	width,
		jab_int32	height,
		jab_int32	type
	)

Mark the positions of finder patterns and alignment patterns in the data map.

Parameters

data_map	the data module positions
width	the width of the data map
height	the height of the data map
type	the symbol type, 0: master, 1: slave

void getNextMetadataModuleInMaster	(	jab_int32	matrix_height,
		jab_int32	matrix_width,
		jab_int32	next_module_count,
		jab_int32 *	x,
		jab_int32 *	y
	)

Get the coordinate of the next metadata module in master symbol.

Parameters

matrix_height	the height of the matrix
matrix_width	the width of the matrix
next_module_count	the index number of the next module
x	the x coordinate of the current and the next module
y	the y coordinate of the current and the next module

jab_boolean getPaletteThreshold	(	jab_byte *	palette,
		jab_int32	color_number,
		jab_float **	palette_ths,
		jab_float **	palette_rp
	)

Get the pixel value thresholds and reference points for each channel of the colors in the palette.

Parameters

palette	the color palette
color_number	the number of colors
palette_ths	the pixel value thresholds
palette_rp	the reference pixel values

Returns

JAB_SUCCESS | JAB_FAILURE

void interpolatePalette	(	jab_byte *	palette,
		jab_int32	color_number
	)

Interpolate 64-color palette into 128-/256-color palette.

Parameters

palette	the color palette
color_number	the number of colors

jab_int32 loadDefaultMasterMetadata	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol,
		jab_byte *	data_map
	)

Load default metadata values and color palettes for master symbol.

Parameters

matrix	the symbol matrix
symbol	the master symbol
data_map	the data module positions

Returns

JAB_SUCCESS | FATAL_ERROR

jab_data* rawModuleData2RawData	(	jab_data *	raw_module_data,
		jab_int32	bits_per_module
	)

Convert multi-bit-per-byte raw module data to one-bit-per-byte raw data.

Parameters

raw_module_data	the input raw module data
bits_per_module	the number of bits per module

Returns

the converted data | NULL if failed

jab_int32 readColorPaletteInMaster	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol,
		jab_byte *	data_map,
		jab_int32 *	module_count,
		jab_int32 *	x,
		jab_int32 *	y
	)

Read the color palettes in master symbol.

Parameters

matrix	the symbol matrix
symbol	the master symbol
data_map	the data module positions
module_count	the start module index
x	the x coordinate of the start module
y	the y coordinate of the start module

Returns

JAB_SUCCESS | FATAL_ERROR

jab_int32 readColorPaletteInSlave	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol,
		jab_byte *	data_map
	)

Read the color palettes in master symbol.

Parameters

matrix	the symbol matrix
symbol	the slave symbol
data_map	the data module positions

Returns

JAB_SUCCESS | FATAL_ERROR

jab_int32 readData	(	jab_data *	data,
		jab_int32	start,
		jab_int32	length,
		jab_int32 *	value
	)

Read bit data.

Parameters

data	the data buffer
start	the start reading offset
length	the length of the data to be read
value	the read data

Returns

the length of the read data

jab_data* readRawModuleData	(	jab_bitmap *	matrix,
		jab_decoded_symbol *	symbol,
		jab_byte *	data_map,
		jab_float **	bits_p
	)

Decode data modules.

Parameters

matrix	the symbol matrix
symbol	the symbol to be decoded
data_map	the data module positions
bits_p	the probability of the reliability of the decoded bits

Returns

the decoded data | NULL if failed