Macros
#define	N_ICC_HEAD_BYTES (N_ICC_MAX_BYTES + 1024u * 1024u)
	Bytes of a file n_icc_from_file() reads to look for a JPEG, PNG or WebP profile, which those formats keep before the image data.
#define	N_ICC_MAX_BYTES (16u * 1024u * 1024u)
	Largest profile returned.

Functions
int	n_icc_from_buffer (const unsigned char data, size_t len, unsigned char icc, size_t icc_len)
	Find the profile embedded in an image file held in memory.
int	n_icc_from_file (const char path, unsigned char icc, size_t icc_len)
	Find the profile embedded in an image file.
int	n_icc_is_profile (const unsigned char *data, size_t len)
	Does a buffer look like an ICC profile: at least a header, a size field no larger than the buffer, and "acsp" at byte 36.

Detailed Description

Macro Definition Documentation

◆ N_ICC_HEAD_BYTES

#define N_ICC_HEAD_BYTES (N_ICC_MAX_BYTES + 1024u * 1024u)

Bytes of a file n_icc_from_file() reads to look for a JPEG, PNG or WebP profile, which those formats keep before the image data.

Definition at line 67 of file n_icc.h.

Referenced by n_icc_from_file().

◆ N_ICC_MAX_BYTES

#define N_ICC_MAX_BYTES (16u * 1024u * 1024u)

Largest profile returned.

Real ones are a few hundred bytes to a few hundred kilobytes, a large lookup table profile a few megabytes.

Definition at line 63 of file n_icc.h.

Referenced by _from_jpeg(), _from_png(), _give(), and _tiff_file().

Function Documentation

◆ n_icc_from_buffer()

int n_icc_from_buffer	(	const unsigned char *	data,
		size_t	len,
		unsigned char **	icc,
		size_t *	icc_len )

Find the profile embedded in an image file held in memory.

The format is told from the buffer's first bytes, not from a name.

Parameters

data	the file's bytes, from its start
len	how many
icc	receives the profile, allocated here and released with free(), or NULL when there is none
icc_len	receives its length, 0 when there is none

Returns: 1 when a profile was found, 0 when the file has none or is not a format read here, -1 on a NULL argument, no memory or a profile that is there but broken

Definition at line 309 of file n_icc.c.

References __n_assert, _from_buffer(), and N_ICC_MORE.

Referenced by expect(), and main().

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◆ n_icc_from_file()

int n_icc_from_file	(	const char *	path,
		unsigned char **	icc,
		size_t *	icc_len )

Find the profile embedded in an image file.

A TIFF's profile is read where its directory says, which may be at the end of a large file; for the other formats the first N_ICC_HEAD_BYTES are read.

Parameters