jp2kheader.c File Reference

#include <string.h>
#include <math.h>
#include "allheaders.h"

Go to the source code of this file.

Macros
#define	DEBUG_CODEC   0

Functions
l_ok	readHeaderJp2k (const char *filename, l_int32 *pw, l_int32 *ph, l_int32 *pbps, l_int32 *pspp, l_int32 *pcodec)
l_ok	freadHeaderJp2k (FILE *fp, l_int32 *pw, l_int32 *ph, l_int32 *pbps, l_int32 *pspp, l_int32 *pcodec)
l_ok	readHeaderMemJp2k (const l_uint8 *data, size_t size, l_int32 *pw, l_int32 *ph, l_int32 *pbps, l_int32 *pspp, l_int32 *pcodec)
l_int32	fgetJp2kResolution (FILE *fp, l_int32 *pxres, l_int32 *pyres)
l_ok	readResolutionMemJp2k (const l_uint8 *data, size_t nbytes, l_int32 *pxres, l_int32 *pyres)

Variables
static const l_int32	MAX_JP2K_WIDTH = 100000
static const l_int32	MAX_JP2K_HEIGHT = 100000

Detailed Description

     Read header
         l_int32          readHeaderJp2k()
         l_int32          freadHeaderJp2k()
         l_int32          readHeaderMemJp2k()
         l_int32          fgetJp2kResolution()
         l_int32          readResolutionMemJp2k()

 Note: these function read image metadata from a jp2k file, without
 using any jp2k libraries.

 To read and write jp2k data, using the OpenJPEG library
 (http://www.openjpeg.org), see jpegio.c.

Definition in file jp2kheader.c.

Macro Definition Documentation

DEBUG_CODEC

#define DEBUG_CODEC   0

Definition at line 55 of file jp2kheader.c.

Function Documentation

fgetJp2kResolution()

l_int32 fgetJp2kResolution	(	FILE *	fp,
		l_int32 *	pxres,
		l_int32 *	pyres )

Definition at line 277 of file jp2kheader.c.

freadHeaderJp2k()

l_ok freadHeaderJp2k	(	FILE *	fp,
		l_int32 *	pw,
		l_int32 *	ph,
		l_int32 *	pbps,
		l_int32 *	pspp,
		l_int32 *	pcodec )

freadHeaderJp2k()

Parameters

[in]	fp	file stream opened for read
[out]	pw	[optional]
[out]	ph	[optional]
[out]	pbps	[optional] bits/sample
[out]	pspp	[optional] samples/pixel
[out]	pcodec	[optional] L_JP2_CODEC or L_J2K_CODEC

Returns

0 if OK, 1 on error

Definition at line 114 of file jp2kheader.c.

References readHeaderMemJp2k().

Referenced by readHeaderJp2k().

readHeaderJp2k()

l_ok readHeaderJp2k	(	const char *	filename,
		l_int32 *	pw,
		l_int32 *	ph,
		l_int32 *	pbps,
		l_int32 *	pspp,
		l_int32 *	pcodec )

readHeaderJp2k()

Parameters

[in]	filename
[out]	pw	[optional]
[out]	ph	[optional]
[out]	pbps	[optional] bits/sample
[out]	pspp	[optional] samples/pixel
[out]	pcodec	[optional] L_JP2_CODEC or L_J2K_CODEC

Returns

0 if OK, 1 on error

Definition at line 81 of file jp2kheader.c.

References freadHeaderJp2k().

readHeaderMemJp2k()

l_ok readHeaderMemJp2k	(	const l_uint8 *	data,
		size_t	size,
		l_int32 *	pw,
		l_int32 *	ph,
		l_int32 *	pbps,
		l_int32 *	pspp,
		l_int32 *	pcodec )

readHeaderMemJp2k()

Parameters

[in]	data
[in]	size	at least 80
[out]	pw	[optional]
[out]	ph	[optional]
[out]	pbps	[optional] bits/sample
[out]	pspp	[optional] samples/pixel
[out]	pcodec	[optional] L_JP2_CODEC or L_J2K_CODEC

Returns

0 if OK, 1 on error

Notes:
     (1) The ISO/IEC reference for jpeg2000 is
              http://www.jpeg.org/public/15444-1annexi.pdf
         and the file format syntax begins at page 127.
     (2) With a image file codec (L_JP2_CODEC), the Image Header Box
         begins with 'ihdr' = 0x69686472 in big-endian order.  This
         typically, but not always, starts on byte 44, with the
         big-endian data fields beginning at byte 48:
              h:    4 bytes
              w:    4 bytes
              spp:  2 bytes
              bps:  1 byte   (contains bps - 1)
     (3) With a codestream codec (L_J2K_CODEC), the first 4 bytes are
         0xff4fff51.  The fields for w and h appear to start on byte 8,
         and the fields for spp and bps appear to start on byte 40.

Definition at line 169 of file jp2kheader.c.

References L_J2K_CODEC, and L_JP2_CODEC.

Referenced by freadHeaderJp2k().

readResolutionMemJp2k()

l_ok readResolutionMemJp2k	(	const l_uint8 *	data,
		size_t	nbytes,
		l_int32 *	pxres,
		l_int32 *	pyres )

readResolutionMemJp2k()

Parameters

[in]	data	const; jp2k-encoded
[in]	nbytes	of data
[out]	pxres	[optional]
[out]	pyres	[optional]

Returns

0 if OK, 1 on error

Definition at line 309 of file jp2kheader.c.

Variable Documentation

MAX_JP2K_HEIGHT

const l_int32 MAX_JP2K_HEIGHT = 100000

static

Definition at line 64 of file jp2kheader.c.

MAX_JP2K_WIDTH

const l_int32 MAX_JP2K_WIDTH = 100000

static

Definition at line 63 of file jp2kheader.c.