Read/write pnm format from/to file and memory. More...

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

Functions
static l_int32	pnmReadNextAsciiValue (FILE fp, l_int32 pval)
static l_int32	pnmSkipCommentLines (FILE *fp)
PIX *	pixReadStreamPnm (FILE *fp)
l_int32	readHeaderPnm (const char filename, PIX ppix, l_int32 pwidth, l_int32 pheight, l_int32 pdepth, l_int32 ptype, l_int32 pbps, l_int32 *pspp)
l_int32	freadHeaderPnm (FILE fp, PIX ppix, l_int32 pwidth, l_int32 pheight, l_int32 pdepth, l_int32 ptype, l_int32 pbps, l_int32 *pspp)
l_int32	pixWriteStreamPnm (FILE fp, PIX pix)
l_int32	pixWriteStreamAsciiPnm (FILE fp, PIX pix)
PIX *	pixReadMemPnm (const l_uint8 *cdata, size_t size)
l_int32	sreadHeaderPnm (const l_uint8 cdata, size_t size, l_int32 pwidth, l_int32 pheight, l_int32 pdepth, l_int32 ptype, l_int32 pbps, l_int32 *pspp)
l_int32	pixWriteMemPnm (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

Read/write pnm format from/to file and memory.

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

    Read/write to memory   [not on windows]
        PIX             *pixReadMemPnm()
        l_int32          sreadHeaderPnm()
        l_int32          pixWriteMemPnm()

    Local helpers
        static l_int32   pnmReadNextAsciiValue();
        static l_int32   pnmSkipCommentLines();
     
    These are here by popular demand, with the help of Mattias
    Kregert (mattias@kregert.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.

Definition in file pnmio.c.

Function Documentation

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 the file.

Definition at line 751 of file pnmio.c.

References ERROR_INT, and PROCNAME.

Referenced by pixReadStreamPnm().

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

Definition at line 784 of file pnmio.c.

References ERROR_INT, and PROCNAME.

Referenced by freadHeaderPnm().

PIX* pixReadStreamPnm ( FILE * fp )

pixReadStreamPnm()

Input: stream opened for read Return: pix, or null on error

Definition at line 96 of file pnmio.c.

References composeRGBPixel(), ERROR_PTR, freadHeaderPnm(), NULL, pixGetData(), pixGetWpl(), pixSetPixel(), pnmReadNextAsciiValue(), PROCNAME, SET_DATA_BYTE, SET_DATA_DIBIT, SET_DATA_QBIT, and SET_DATA_TWO_BYTES.

Referenced by pixReadStream().

l_int32 readHeaderPnm	(	const char *	filename,
		PIX **	ppix,
		l_int32 *	pwidth,
		l_int32 *	pheight,
		l_int32 *	pdepth,
		l_int32 *	ptype,
		l_int32 *	pbps,
		l_int32 *	pspp
	)

readHeaderPnm()

Input: filename &pix (<optional return>=""> use null to return only header data) &width (<return>) &height (<return>) &depth (<return>) &type (<return> pnm type) &bps (<optional return>="">, bits/sample) &spp (<optional return>="">, samples/pixel) Return: 0 if OK, 1 on error

Definition at line 214 of file pnmio.c.

References ERROR_INT, fopenReadStream(), freadHeaderPnm(), NULL, and PROCNAME.

Referenced by pixReadHeader().

l_int32 freadHeaderPnm	(	FILE *	fp,
		PIX **	ppix,
		l_int32 *	pwidth,
		l_int32 *	pheight,
		l_int32 *	pdepth,
		l_int32 *	ptype,
		l_int32 *	pbps,
		l_int32 *	pspp
	)

freadHeaderPnm()

Input: stream opened for read &pix (<optional return>=""> use null to return only header data) &width (<return>) &height (<return>) &depth (<return>) &type (<return> pnm type) &bps (<optional return>="">, bits/sample) &spp (<optional return>="">, samples/pixel) Return: 0 if OK, 1 on error

Definition at line 254 of file pnmio.c.

References ERROR_INT, L_WARNING_INT, MAX_PNM_HEIGHT, MAX_PNM_WIDTH, NULL, pixCreate(), pnmSkipCommentLines(), and PROCNAME.

Referenced by pixReadStreamPnm(), and readHeaderPnm().

l_int32 pixWriteStreamPnm	(	FILE *	fp,
		PIX *	pix
	)

pixWriteStreamPnm()

Input: stream opened for write pix Return: 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 344 of file pnmio.c.

References ERROR_INT, GET_DATA_BYTE, GET_DATA_DIBIT, GET_DATA_QBIT, GET_DATA_TWO_BYTES, NULL, pixClone(), pixDestroy(), pixGetColormap(), pixGetData(), pixGetDepth(), pixGetDimensions(), pixGetWpl(), pixRemoveColormap(), PROCNAME, and REMOVE_CMAP_BASED_ON_SRC.

Referenced by pixWriteStream().

l_int32 pixWriteStreamAsciiPnm	(	FILE *	fp,
		PIX *	pix
	)

pixWriteStreamAsciiPnm()

Input: stream opened for write pix Return: 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 464 of file pnmio.c.

References COLOR_BLUE, COLOR_GREEN, COLOR_RED, ERROR_INT, GET_DATA_BYTE, NULL, pixClone(), pixDestroy(), pixGetColormap(), pixGetDepth(), pixGetDimensions(), pixGetPixel(), pixRemoveColormap(), PROCNAME, and REMOVE_CMAP_BASED_ON_SRC.

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

Definition at line 701 of file pnmio.c.

References ERROR_PTR, and NULL.

Referenced by pixReadMem().

l_int32 sreadHeaderPnm	(	const l_uint8 *	cdata,
		size_t	size,
		l_int32 *	pwidth,
		l_int32 *	pheight,
		l_int32 *	pdepth,
		l_int32 *	ptype,
		l_int32 *	pbps,
		l_int32 *	pspp
	)