pngunpack.c File Reference

Contains a function to unpack data packed with PNG compression. More...

#include <stdio.h>
#include <stdlib.h>
#include "grib2.h"

Go to the source code of this file.

Functions
int	dec_png (unsigned char *, g2int *, g2int *, char *)
	Decode PNG. More...
g2int	pngunpack (unsigned char *cpack, g2int len, g2int *idrstmpl, g2int ndpts, g2float *fld)
	This subroutine unpacks a data field that was packed into a PNG image format using info from the GRIB2 Data Representation Template 5.41 or 5.40010. More...

Detailed Description

Contains a function to unpack data packed with PNG compression.

Author

Stephen Gilbert

Date

2003-08-27

Definition in file pngunpack.c.

Function Documentation

dec_png()

int dec_png	(	unsigned char *	pngbuf,
		g2int *	width,
		g2int *	height,
		char *	cout
	)

Decode PNG.

Parameters

pngbuf	Pointer to PNG buffer.
width	Pointer to width.
height	Pointer to height.
cout	Output buffer.

Returns

0 for success, error code otherwise.

Author

Stephen Gilbert

Definition at line 71 of file dec_png.c.

References user_read_data().

Referenced by pngunpack().

pngunpack()

g2int pngunpack	(	unsigned char *	cpack,
		g2int	len,
		g2int *	idrstmpl,
		g2int	ndpts,
		g2float *	fld
	)

This subroutine unpacks a data field that was packed into a PNG image format using info from the GRIB2 Data Representation Template 5.41 or 5.40010.

Parameters

cpack	The packed data field (character*1 array).
len	length of packed field cpack().
idrstmpl	Pointer to array of values for Data Representation Template 5.41 or 5.40010.
ndpts	The number of data values to unpack.
fld	Contains the unpacked data values.

Returns

0 for success, 1 for memory allocation error.

Author

Stephen Gilbert

Date

2003-08-27

Definition at line 30 of file pngunpack.c.

References dec_png(), gbits(), int_power(), and rdieee().

Referenced by g2_unpack7().