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

Functions
static l_int32	pnmReadNextAsciiValue (FILE fp, l_int32 pval)

static l_int32	pnmReadNextNumber (FILE fp, l_int32 pval)

static l_int32	pnmReadNextString (FILE fp, char buff, l_int32 size)

static l_int32	pnmSkipCommentLines (FILE *fp)

PIX *	pixReadStreamPnm (FILE *fp)

l_ok	readHeaderPnm (const char filename, l_int32 pw, l_int32 ph, l_int32 pd, l_int32 ptype, l_int32 pbps, l_int32 *pspp)

l_ok	freadHeaderPnm (FILE fp, l_int32 pw, l_int32 ph, l_int32 pd, l_int32 ptype, l_int32 pbps, l_int32 *pspp)

l_ok	pixWriteStreamPnm (FILE fp, PIX pix)

l_ok	pixWriteStreamAsciiPnm (FILE fp, PIX pix)

l_ok	pixWriteStreamPam (FILE fp, PIX pix)

PIX *	pixReadMemPnm (const l_uint8 *data, size_t size)

l_ok	readHeaderMemPnm (const l_uint8 data, size_t size, l_int32 pw, l_int32 ph, l_int32 pd, l_int32 ptype, l_int32 pbps, l_int32 *pspp)

l_ok	pixWriteMemPnm (l_uint8 *pdata, size_t psize, PIX *pix)

l_ok	pixWriteMemPam (l_uint8 *pdata, size_t psize, PIX *pix)

Variables
static const l_int32	MAX_PNM_WIDTH = 100000

static const l_int32	MAX_PNM_HEIGHT = 100000

Detailed Description


     Stream interface
         PIX             *pixReadStreamPnm()
         l_int32          readHeaderPnm()
         l_int32          freadHeaderPnm()
         l_int32          pixWriteStreamPnm()
         l_int32          pixWriteStreamAsciiPnm()
         l_int32          pixWriteStreamPam()

     Read/write to memory
         PIX             *pixReadMemPnm()
         l_int32          readHeaderMemPnm()
         l_int32          pixWriteMemPnm()
         l_int32          pixWriteMemPam()

     Local helpers
         static l_int32   pnmReadNextAsciiValue();
         static l_int32   pnmReadNextNumber();
         static l_int32   pnmReadNextString();
         static l_int32   pnmSkipCommentLines();

     These are here by popular demand, with the help of Mattias
     Kregert (matti.nosp@m.as@k.nosp@m.reger.nosp@m.t.se), who provided the first implementation.

     The pnm formats are exceedingly simple, because they have
     no compression and no colormaps.  They support images that
     are 1 bpp; 2, 4, 8 and 16 bpp grayscale; and rgb.

     The original pnm formats ("ASCII") are included for completeness,
     but their use is deprecated for all but tiny iconic images.
     They are extremely wasteful of memory; for example, the P1 binary
     ASCII format is 16 times as big as the packed uncompressed
     format, because 2 characters are used to represent every bit
     (pixel) in the image.  Reading is slow because we check for extra
     white space and EOL at every sample value.

     The packed pnm formats ("raw") give file sizes similar to
     bmp files, which are uncompressed packed.  However, bmp
     are more flexible, because they can support colormaps.

     We don't differentiate between the different types ("pbm",
     "pgm", "ppm") at the interface level, because this is really a
     "distinction without a difference."  You read a file, you get
     the appropriate Pix.  You write a file from a Pix, you get the
     appropriate type of file.  If there is a colormap on the Pix,
     and the Pix is more than 1 bpp, you get either an 8 bpp pgm
     or a 24 bpp RGB pnm, depending on whether the colormap colors
     are gray or rgb, respectively.

     This follows the general policy that the I/O routines don't
     make decisions about the content of the image -- you do that
     with image processing before you write it out to file.
     The I/O routines just try to make the closest connection
     possible between the file and the Pix in memory.

     On systems like Windows without fmemopen() and open_memstream(),
     we write data to a temp file and read it back for operations
     between pix and compressed-data, such as pixReadMemPnm() and
     pixWriteMemPnm().

     The P7 format is new. It introduced a header with multiple
     lines containing distinct tags for the various fields.
     See: http://netpbm.sourceforge.net/doc/pam.html

       WIDTH <int>         ; mandatory, exactly once
       HEIGHT <int>        ; mandatory, exactly once
       DEPTH <int>         ; mandatory, exactly once,
                           ; its meaning is equivalent to spp
       MAXVAL <int>        ; mandatory, one of 1, 3, 15, 255 or 65535
       TUPLTYPE <string>   ; optional; BLACKANDWHITE, GRAYSCALE, RGB
                           ; and optional suffix _ALPHA, e.g. RGB_ALPHA
       ENDHDR              ; mandatory, last header line

     Reading BLACKANDWHITE_ALPHA and GRAYSCALE_ALPHA, which have a DEPTH
     value of 2, is supported. The original image is converted to a Pix
     with 32-bpp and alpha channel (spp == 4).

     Writing P7 format is currently selected for 32-bpp with alpha
     channel, i.e. for Pix which have spp == 4, using pixWriteStreamPam().

     Jürgen Buchmüller provided the implementation for the P7 (pam) format.

     Giulio Lunati made an elegant reimplementation of the static helper
     functions using fscanf() instead of fseek(), so that it works with
     pnm data from stdin.

Definition in file pnmio.c.

Function Documentation

◆ freadHeaderPnm()

l_ok freadHeaderPnm	(	FILE *	fp,
		l_int32 *	pw,
		l_int32 *	ph,
		l_int32 *	pd,
		l_int32 *	ptype,
		l_int32 *	pbps,
		l_int32 *	pspp )

freadHeaderPnm()

Parameters

[in]	fp	file stream opened for read
[out]	pw	[optional]
[out]	ph	[optional]
[out]	pd	[optional]
[out]	ptype	[optional] pnm type
[out]	pbps	[optional] bits/sample
[out]	pspp	[optional] samples/pixel

Returns: 0 if OK, 1 on error

Definition at line 559 of file pnmio.c.

References pnmReadNextNumber(), pnmReadNextString(), and pnmSkipCommentLines().

Referenced by pixReadStreamPnm(), readHeaderMemPnm(), and readHeaderPnm().

◆ pixReadMemPnm()

PIX * pixReadMemPnm	(	const l_uint8 *	data,
		size_t	size )

pixReadMemPnm()

Parameters

[in]	data	const; pnm-encoded
[in]	size	of data

Returns: pix, or NULL on error

Notes:
     (1) The size byte of data must be a null character.

Definition at line 1147 of file pnmio.c.

References pixReadStreamPnm().

◆ pixReadStreamPnm()

PIX * pixReadStreamPnm ( FILE * fp )

pixReadStreamPnm()

Parameters

[in] fp file stream opened for read

Returns: pix, or NULL on error

Definition at line 150 of file pnmio.c.

References freadHeaderPnm(), pnmReadNextAsciiValue(), SET_DATA_BYTE, SET_DATA_DIBIT, SET_DATA_QBIT, and SET_DATA_TWO_BYTES.

Referenced by pixReadMemPnm().

◆ pixWriteMemPam()

l_ok pixWriteMemPam	(	l_uint8 **	pdata,
		size_t *	psize,
		PIX *	pix )

pixWriteMemPam()

Parameters

[out]	pdata	data of PAM image
[out]	psize	size of returned data
[in]	pix

Returns: 0 if OK, 1 on error

Notes:
     (1) See pixWriteStreamPnm() for usage.  This version writes to
         memory instead of to a file stream.

Definition at line 1274 of file pnmio.c.

References pixWriteStreamPam().

◆ pixWriteMemPnm()

l_ok pixWriteMemPnm	(	l_uint8 **	pdata,
		size_t *	psize,
		PIX *	pix )

pixWriteMemPnm()

Parameters

[out]	pdata	data of PNM image
[out]	psize	size of returned data
[in]	pix

Returns: 0 if OK, 1 on error

Notes:
     (1) See pixWriteStreamPnm() for usage.  This version writes to
         memory instead of to a file stream.

Definition at line 1218 of file pnmio.c.

References pixWriteStreamPnm().

◆ pixWriteStreamAsciiPnm()

l_ok pixWriteStreamAsciiPnm	(	FILE *	fp,
		PIX *	pix )

pixWriteStreamAsciiPnm()

Parameters

[in]	fp	file stream opened for write
[in]	pix

Returns: 0 if OK; 1 on error

Writes "ASCII" format only: 1 bpp --> pbm P1 2, 4, 8, 16 bpp, no colormap or grayscale colormap --> pgm P2 2, 4, 8 bpp with color-valued colormap, or rgb --> rgb ppm P3

Definition at line 853 of file pnmio.c.

References COLOR_BLUE, COLOR_GREEN, COLOR_RED, GET_DATA_BYTE, and REMOVE_CMAP_BASED_ON_SRC.

◆ pixWriteStreamPam()

l_ok pixWriteStreamPam	(	FILE *	fp,
		PIX *	pix )

pixWriteStreamPam()

Parameters

[in]	fp	file stream opened for write
[in]	pix

Returns: 0 if OK; 1 on error

Notes:
     (1) This writes arbitrary PAM (P7) packed format.
     (2) 24 bpp rgb are not supported in leptonica, but this will
         write them out as a packed array of bytes (3 to a pixel).

Definition at line 973 of file pnmio.c.

References COLOR_BLUE, COLOR_GREEN, COLOR_RED, GET_DATA_BIT, GET_DATA_BYTE, GET_DATA_DIBIT, GET_DATA_QBIT, GET_DATA_TWO_BYTES, L_ALPHA_CHANNEL, and REMOVE_CMAP_BASED_ON_SRC.

Referenced by pixWriteMemPam(), and pixWriteStreamPnm().

◆ pixWriteStreamPnm()

l_ok pixWriteStreamPnm	(	FILE *	fp,
		PIX *	pix )

pixWriteStreamPnm()

Parameters

[in]	fp	file stream opened for write
[in]	pix

Returns: 0 if OK; 1 on error

Notes:
     (1) This writes "raw" packed format only:
         1 bpp --> pbm (P4)
         2, 4, 8, 16 bpp, no colormap or grayscale colormap --> pgm (P5)
         2, 4, 8 bpp with color-valued colormap, or rgb --> rgb ppm (P6)
     (2) 24 bpp rgb are not supported in leptonica, but this will
         write them out as a packed array of bytes (3 to a pixel).

Definition at line 736 of file pnmio.c.

References COLOR_BLUE, COLOR_GREEN, COLOR_RED, GET_DATA_BYTE, GET_DATA_DIBIT, GET_DATA_QBIT, GET_DATA_TWO_BYTES, pixWriteStreamPam(), and REMOVE_CMAP_BASED_ON_SRC.

Referenced by pixWriteMemPnm().

◆ pnmReadNextAsciiValue()

static l_int32 pnmReadNextAsciiValue	(	FILE *	fp,
		l_int32 *	pval )

static

pnmReadNextAsciiValue()

Return: 0 if OK, 1 on error or EOF.

Notes: (1) This reads the next sample value in ASCII from the file.

Definition at line 1327 of file pnmio.c.

Referenced by pixReadStreamPnm().

◆ pnmReadNextNumber()

static l_int32 pnmReadNextNumber	(	FILE *	fp,
		l_int32 *	pval )

static

pnmReadNextNumber()

Parameters

[in]	fp	file stream
[out]	pval	value as an integer

Returns: 0 if OK, 1 on error or EOF.

Notes:
     (1) This reads the next set of numeric chars, returning
         the value and swallowing initial whitespaces and ONE
         trailing whitespace character.  This is needed to read
         the maxval in the header, which precedes the binary data.

Definition at line 1363 of file pnmio.c.

Referenced by freadHeaderPnm().

◆ pnmReadNextString()

static l_int32 pnmReadNextString	(	FILE *	fp,
		char *	buff,
		l_int32	size )

static

pnmReadNextString()

Parameters

[in]	fp	file stream
[out]	buff	pointer to the string buffer
[in]	size	max. number of characters in buffer

Returns: 0 if OK, 1 on error or EOF.

Notes:
     (1) This reads the next set of alphanumeric chars, returning the string.
         This is needed to read header lines, which precede the P7
         format binary data.

Definition at line 1419 of file pnmio.c.

References pnmSkipCommentLines().

Referenced by freadHeaderPnm().

◆ pnmSkipCommentLines()

static l_int32 pnmSkipCommentLines ( FILE * fp )

static

pnmSkipCommentLines()

Return: 0 if OK, 1 on error or EOF

Notes: (1) Comment lines begin with '#' (2) Usage: caller should check return value for EOF (3) The previous implementation used fseek(fp, -1L, SEEK_CUR) to back up one character, which doesn't work with stdin.

Definition at line 1463 of file pnmio.c.

Referenced by freadHeaderPnm(), and pnmReadNextString().

◆ readHeaderMemPnm()

l_ok readHeaderMemPnm	(	const l_uint8 *	data,
		size_t	size,
		l_int32 *	pw,
		l_int32 *	ph,
		l_int32 *	pd,
		l_int32 *	ptype,
		l_int32 *	pbps,
		l_int32 *	pspp )

readHeaderMemPnm()

Parameters

[in]	data	const; pnm-encoded
[in]	size	of data
[out]	pw	[optional]
[out]	ph	[optional]
[out]	pd	[optional]
[out]	ptype	[optional] pnm type
[out]	pbps	[optional] bits/sample
[out]	pspp	[optional] samples/pixel

Returns: 0 if OK, 1 on error

Definition at line 1178 of file pnmio.c.

References freadHeaderPnm().

◆ readHeaderPnm()

l_ok readHeaderPnm	(	const char *	filename,
		l_int32 *	pw,
		l_int32 *	ph,
		l_int32 *	pd,
		l_int32 *	ptype,
		l_int32 *	pbps,
		l_int32 *	pspp )

readHeaderPnm()

Parameters

[in]	filename
[out]	pw	[optional]
[out]	ph	[optional]
[out]	pd	[optional]
[out]	ptype	[optional] pnm type
[out]	pbps	[optional] bits/sample
[out]	pspp	[optional] samples/pixel

Returns: 0 if OK, 1 on error

Definition at line 518 of file pnmio.c.

References freadHeaderPnm().

Variable Documentation

◆ MAX_PNM_HEIGHT

const l_int32 MAX_PNM_HEIGHT = 100000

static

Definition at line 137 of file pnmio.c.

◆ MAX_PNM_WIDTH

const l_int32 MAX_PNM_WIDTH = 100000

static

Definition at line 136 of file pnmio.c.

Functions

Variables

Detailed Description

Function Documentation

◆ freadHeaderPnm()

◆ pixReadMemPnm()

◆ pixReadStreamPnm()

◆ pixWriteMemPam()

◆ pixWriteMemPnm()

◆ pixWriteStreamAsciiPnm()

◆ pixWriteStreamPam()

◆ pixWriteStreamPnm()

◆ pnmReadNextAsciiValue()

◆ pnmReadNextNumber()

◆ pnmReadNextString()

◆ pnmSkipCommentLines()

◆ readHeaderMemPnm()

◆ readHeaderPnm()

Variable Documentation

◆ MAX_PNM_HEIGHT

◆ MAX_PNM_WIDTH