Pack and unpack an array of float/double using JPEG2000. More...

#include <stdlib.h>
#include <math.h>
#include "grib2_int.h"

Functions
int	g2c_jpcpackd (double fld, size_t width, size_t height, int idrstmpl, unsigned char cpack, size_t lcpack)
	This function packs up a double array into a JPEG2000 code stream. More...

int	g2c_jpcpackf (float fld, size_t width, size_t height, int idrstmpl, unsigned char cpack, size_t lcpack)
	This function packs up a float array into a JPEG2000 code stream. More...

void	jpcpack (float fld, g2int width, g2int height, g2int idrstmpl, unsigned char cpack, g2int lcpack)
	This function packs up a float array into a JPEG2000 code stream. More...

static int	jpcpack_int (void fld, int fld_is_double, g2int width, g2int height, g2int idrstmpl, unsigned char cpack, g2int lcpack, int verbose)
	This internal function packs up a float or double array into a JPEG2000 code stream. More...

Detailed Description

Pack and unpack an array of float/double using JPEG2000.

Author: Stephen Gilbert

Date: 2003-08-17

Program History Log

Date	Programmer	Comments
2003-08-17	Gilbert	Initial.
2004-11-92	Gilbert	Fixed bug packing a near constant field.
2004-07-19	Gilbert	If jpeg2000 encoding fails, try again with different encoder options.
2005-05-10	Gilbert	Imposed minimum size on cpack.
2022-08-12	Hartnett	Now handle doubles too.

Definition in file jpcpack.c.

Function Documentation

◆ g2c_jpcpackd()

int g2c_jpcpackd	(	double *	fld,
		size_t	width,
		size_t	height,
		int *	idrstmpl,
		unsigned char *	cpack,
		size_t *	lcpack
	)

This function packs up a double array into a JPEG2000 code stream.

After the data are scaled, and the reference value is subtracted out, the data are treated as a grayscale image and passed to a JPEG2000 encoder.

This function also fills in GRIB2 Data Representation Template 5.40 or 5.40000 with the appropriate values.

This function is the V2 API version of jpcpack() for doubles.

Parameters

fld	Pointer to the double data values to pack.
width	The number of points in the x direction.
height	The number of points in the y direction.
idrstmpl	Contains the array of values for Data Representation Template Table 5.40 or 5.40000. 0 Reference value - ignored on input, set by jpcpack routine. 1 Binary Scale Factor - used on input, unchanged by jpcpack routine. 2 Decimal Scale Factor - used on input, unchanged by jpcpack routine. 3 number of bits for each data value - ignored on input 4 Original field type - currently ignored on input Data values assumed to be reals. Set to 0 on output. 5 if 0 use lossless compression, if 1 use lossy compression. 6 Desired compression ratio, if idrstmpl[5]=1. Set to 255, if idrstmpl[5]=0. May be modified in this function.
cpack	A pointer that will get the packed data field. Must be allocated before this function is called. Pass the allocated size in the lcpack parameter.
lcpack	Pointer that gets the length of packed field in cpack. This must be set by the calling function to the size available in cpack.

Returns

G2C_NOERROR No error.
G2C_EJPEG Error encoding/decoding JPEG data.

Author: Ed Hartnett

Definition at line 387 of file jpcpack.c.

References G2C_JPEG_DRS_TEMPLATE_LEN, and jpcpack_int().

◆ g2c_jpcpackf()

int g2c_jpcpackf	(	float *	fld,
		size_t	width,
		size_t	height,
		int *	idrstmpl,
		unsigned char *	cpack,
		size_t *	lcpack
	)

This function packs up a float array into a JPEG2000 code stream.

After the data are scaled, and the reference value is subtracted out, the data are treated as a grayscale image and passed to a JPEG2000 encoder.

This function also fills in GRIB2 Data Representation Template 5.40 or 5.40000 with the appropriate values.

This function is the V2 API version of jpcpack() for floats.

Parameters

fld	Pointer to the float data values to pack.
width	The number of points in the x direction.
height	The number of points in the y direction.
idrstmpl	Contains the array of values for Data Representation Template Table 5.40 or 5.40000. 0 Reference value - ignored on input, set by jpcpack routine. 1 Binary Scale Factor - used on input, unchanged by jpcpack routine. 2 Decimal Scale Factor - used on input, unchanged by jpcpack routine. 3 number of bits for each data value - ignored on input 4 Original field type - currently ignored on input Data values assumed to be reals. Set to 0 on output. 5 if 0 use lossless compression, if 1 use lossy compression. 6 Desired compression ratio, if idrstmpl[5]=1. Set to 255, if idrstmpl[5]=0. May be modified in this function.
cpack	A pointer that will get the packed data field. Must be allocated before this function is called. Pass the allocated size in the lcpack parameter.
lcpack	Pointer that gets the length of packed field in cpack. This must be set by the calling function to the size available in cpack.

Returns

G2C_NOERROR No error.
G2C_EJPEG Error encoding/decoding JPEG data.

Author: Ed Hartnett

Definition at line 321 of file jpcpack.c.

References G2C_JPEG_DRS_TEMPLATE_LEN, and jpcpack_int().

◆ jpcpack()

void jpcpack	(	float *	fld,
		g2int	width,
		g2int	height,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack
	)

This function packs up a float array into a JPEG2000 code stream.

After the data are scaled, and the reference value is subtracted out, the data are treated as a grayscale image and passed to a JPEG2000 encoder.

This function also fills in GRIB2 Data Representation Template 5.40 or 5.40000 with the appropriate values.

Parameters

fld	Pointer to the float data values to pack.
width	The number of points in the x direction.
height	The number of points in the y direction.
idrstmpl	Contains the array of values for Data Representation Template Table 5.40 or 5.40000. 0 Reference value - ignored on input, set by jpcpack routine. 1 Binary Scale Factor - used on input, unchanged by jpcpack routine. 2 Decimal Scale Factor - used on input, unchanged by jpcpack routine. 3 number of bits for each data value - ignored on input 4 Original field type - currently ignored on input Data values assumed to be reals. Set to 0 on output. 5 if 0 use lossless compression, if 1 use lossy compression. 6 Desired compression ratio, if idrstmpl[5]=1. Set to 255, if idrstmpl[5]=0. May be modified in this function.
cpack	A pointer that will get the packed data field. Must be allocated before this function is called. Pass the allocated size in the lcpack parameter.
lcpack	Pointer that gets the length of packed field in cpack. This must be set by the calling function to the size available in cpack.

Author: Stephen Gilbert, Ed Hartnett

Definition at line 270 of file jpcpack.c.

References jpcpack_int().

Referenced by g2_addfield().

◆ jpcpack_int()

static int jpcpack_int	(	void *	fld,
		int	fld_is_double,
		g2int	width,
		g2int	height,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack,
		int	verbose
	)

static

This internal function packs up a float or double array into a JPEG2000 code stream.

This function is used by jpcpack(), g2c_jpcpackf(), and g2c_jpcpackd().

Parameters

fld	Pointer to the float or double data values to pack.
fld_is_double	If non-zero, then fld points to array of doubles, otherwise an array of floats.
width	The number of points in the x direction.
height	The number of points in the y direction.
idrstmpl	Contains the array of values for Data Representation Template Table 5.40 or 5.40000. May be modified in this function.
cpack	A pointer that will get the packed data field. Must be allocated before this function is called. Pass the allocated size in the lcpack parameter.
lcpack	Pointer that gets the length of packed field in cpack. This must also be set by the calling function to the size available in cpack.
verbose	If non-zero, error messages will be printed in case of error. Otherwise, error codes will be return but no error messages printed. Calls to the original g2c API may cause error messages to be printed in case of error. For the new g2c_ API, no error messages will be printed - instead an error code will be returned. Call g2c_strerror() to get the error message for any error code.

Returns

G2C_NOERROR No error.
G2C_EJPEG Error encoding/decoding JPEG data.

Author: Stephen Gilbert, Ed Hartnett

Definition at line 55 of file jpcpack.c.

References ALOG2, enc_jpeg2000(), G2C_EJPEG, G2C_NOERROR, int_power(), LOG, mkieee(), and sbits().

Referenced by g2c_jpcpackd(), g2c_jpcpackf(), and jpcpack().

Functions

Detailed Description

Program History Log

Function Documentation

◆ g2c_jpcpackd()

◆ g2c_jpcpackf()

◆ jpcpack()

◆ jpcpack_int()