/*

* pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file

* copyright (C) 1999 by Willem van Schaik <willem@schaik.com>

*

* version 1.0 - 1999.10.15 - First version.

*

* Permission to use, copy, modify, and distribute this software and

* its documentation for any purpose and without fee is hereby granted,

* provided that the above copyright notice appear in all copies and

* that both that copyright notice and this permission notice appear in

* supporting documentation. This software is provided "as is" without

* express or implied warranty.

*/

#include <stdio.h>

#include <stdlib.h>

#ifdef __TURBOC__

#include <mem.h>

#include <fcntl.h>

#endif

#ifndef BOOL

#define BOOL unsigned char

#endif

#ifndef TRUE

#define TRUE (BOOL) 1

#endif

#ifndef FALSE

#define FALSE (BOOL) 0

#endif

#define STDIN 0

#define STDOUT 1

#define STDERR 2

/* to make pnm2png verbose so we can find problems (needs to be before png.h) */

#ifndef PNG_DEBUG

#define PNG_DEBUG 0

#endif

#include "png.h"

/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */

#ifndef png_jmpbuf

# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)

#endif

/* function prototypes */

int main (int argc, char *argv[]);

void usage ();

BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);

void get_token(FILE *pnm_file, char *token);

png_uint_32 get_data (FILE *pnm_file, int depth);

png_uint_32 get_value (FILE *pnm_file, int depth);

/*

* main

*/

int main(int argc, char *argv[])

{

FILE *fp_rd = stdin;

FILE *fp_al = NULL;

FILE *fp_wr = stdout;

BOOL interlace = FALSE;

BOOL alpha = FALSE;

int argi;

for (argi = 1; argi < argc; argi++)

{

if (argv[argi][0] == '-')

{

switch (argv[argi][1])

{

case 'i':

interlace = TRUE;

break;

case 'a':

alpha = TRUE;

argi++;

if ((fp_al = fopen (argv[argi], "rb")) == NULL)

{

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, "Error: alpha-channel file %s does not exist\n",

argv[argi]);

exit (1);

}

break;

case 'h':

case '?':

usage();

exit(0);

break;

default:

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, "Error: unknown option %s\n", argv[argi]);

usage();

exit(1);

break;

} /* end switch */

}

else if (fp_rd == stdin)

{

if ((fp_rd = fopen (argv[argi], "rb")) == NULL)

{

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, "Error: file %s does not exist\n", argv[argi]);

exit (1);

}

}

else if (fp_wr == stdout)

{

if ((fp_wr = fopen (argv[argi], "wb")) == NULL)

{

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, "Error: can not create PNG-file %s\n", argv[argi]);

exit (1);

}

}

else

{

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, "Error: too many parameters\n");

usage();

exit (1);

}

} /* end for */

#ifdef __TURBOC__

/* set stdin/stdout to binary, we're reading the PNM always! in binary format */

if (fp_rd == stdin)

{

setmode (STDIN, O_BINARY);

}

if (fp_wr == stdout)

{

setmode (STDOUT, O_BINARY);

}

#endif

/* call the conversion program itself */

if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)

{

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, "Error: unsuccessful converting to PNG-image\n");

exit (1);

}

/* close input file */

fclose (fp_rd);

/* close output file */

fclose (fp_wr);

/* close alpha file */

if (alpha)

fclose (fp_al);

return 0;

}

/*

* usage

*/

void usage()

{

fprintf (stderr, "PNM2PNG\n");

fprintf (stderr, " by Willem van Schaik, 1999\n");

#ifdef __TURBOC__

fprintf (stderr, " for Turbo-C and Borland-C compilers\n");

#else

fprintf (stderr, " for Linux (and Unix) compilers\n");

#endif

fprintf (stderr, "Usage: pnm2png [options] <file>.<pnm> [<file>.png]\n");

fprintf (stderr, " or: ... | pnm2png [options]\n");

fprintf (stderr, "Options:\n");

fprintf (stderr, " -i[nterlace] write png-file with interlacing on\n");

fprintf (stderr, " -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");

fprintf (stderr, " -h | -? print this help-information\n");

}

/*

* pnm2png

*/

BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)

{

png_struct *png_ptr = NULL;

png_info *info_ptr = NULL;

png_byte *png_pixels = NULL;

png_byte **row_pointers = NULL;

png_byte *pix_ptr = NULL;

png_uint_32 row_bytes;

char type_token[16];

char width_token[16];

char height_token[16];

char maxval_token[16];

int color_type;

png_uint_32 width, alpha_width;

png_uint_32 height, alpha_height;

png_uint_32 maxval;

int bit_depth = 0;

int channels;

int alpha_depth = 0;

int alpha_present;

int row, col;

BOOL raw, alpha_raw = FALSE;

png_uint_32 tmp16;

int i;

/* read header of PNM file */

get_token(pnm_file, type_token);

if (type_token[0] != 'P')

{

return FALSE;

}

else if ((type_token[1] == '1') || (type_token[1] == '4'))

{

raw = (type_token[1] == '4');

color_type = PNG_COLOR_TYPE_GRAY;

bit_depth = 1;

}

else if ((type_token[1] == '2') || (type_token[1] == '5'))

{

raw = (type_token[1] == '5');

color_type = PNG_COLOR_TYPE_GRAY;

get_token(pnm_file, width_token);

sscanf (width_token, "%lu", &width);

get_token(pnm_file, height_token);

sscanf (height_token, "%lu", &height);

get_token(pnm_file, maxval_token);

sscanf (maxval_token, "%lu", &maxval);

if (maxval <= 1)

bit_depth = 1;

else if (maxval <= 3)

bit_depth = 2;

else if (maxval <= 15)

bit_depth = 4;

else if (maxval <= 255)

bit_depth = 8;

else /* if (maxval <= 65535) */

bit_depth = 16;

}

else if ((type_token[1] == '3') || (type_token[1] == '6'))

{

raw = (type_token[1] == '6');

color_type = PNG_COLOR_TYPE_RGB;

get_token(pnm_file, width_token);

sscanf (width_token, "%lu", &width);

get_token(pnm_file, height_token);

sscanf (height_token, "%lu", &height);

get_token(pnm_file, maxval_token);

sscanf (maxval_token, "%lu", &maxval);

if (maxval <= 1)

bit_depth = 1;

else if (maxval <= 3)

bit_depth = 2;

else if (maxval <= 15)

bit_depth = 4;

else if (maxval <= 255)

bit_depth = 8;

else /* if (maxval <= 65535) */

bit_depth = 16;

}

else

{

return FALSE;

}

/* read header of PGM file with alpha channel */

if (alpha)

{

if (color_type == PNG_COLOR_TYPE_GRAY)

color_type = PNG_COLOR_TYPE_GRAY_ALPHA;

if (color_type == PNG_COLOR_TYPE_RGB)

color_type = PNG_COLOR_TYPE_RGB_ALPHA;

get_token(alpha_file, type_token);

if (type_token[0] != 'P')

{

return FALSE;

}

else if ((type_token[1] == '2') || (type_token[1] == '5'))

{

alpha_raw = (type_token[1] == '5');

get_token(alpha_file, width_token);

sscanf (width_token, "%lu", &alpha_width);

if (alpha_width != width)

return FALSE;

get_token(alpha_file, height_token);

sscanf (height_token, "%lu", &alpha_height);

if (alpha_height != height)

return FALSE;

get_token(alpha_file, maxval_token);

sscanf (maxval_token, "%lu", &maxval);

if (maxval <= 1)

alpha_depth = 1;

else if (maxval <= 3)

alpha_depth = 2;

else if (maxval <= 15)

alpha_depth = 4;

else if (maxval <= 255)

alpha_depth = 8;

else /* if (maxval <= 65535) */

alpha_depth = 16;

if (alpha_depth != bit_depth)

return FALSE;

}

else

{

return FALSE;

}

} /* end if alpha */

/* calculate the number of channels and store alpha-presence */

if (color_type == PNG_COLOR_TYPE_GRAY)

channels = 1;

else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)

channels = 2;

else if (color_type == PNG_COLOR_TYPE_RGB)

channels = 3;

else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)

channels = 4;

else

channels = 0; /* should not happen */

alpha_present = (channels - 1) % 2;

/* row_bytes is the width x number of channels x (bit-depth / 8) */

row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);

if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)

return FALSE;

/* read data from PNM file */

pix_ptr = png_pixels;

for (row = 0; row < height; row++)

{

for (col = 0; col < width; col++)

{

for (i = 0; i < (channels - alpha_present); i++)

{

if (raw)

*pix_ptr++ = get_data (pnm_file, bit_depth);

else

if (bit_depth <= 8)

*pix_ptr++ = get_value (pnm_file, bit_depth);

else

{

tmp16 = get_value (pnm_file, bit_depth);

*pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);

pix_ptr++;

*pix_ptr = (png_byte) (tmp16 & 0xFF);

pix_ptr++;

}

}

if (alpha) /* read alpha-channel from pgm file */

{

if (alpha_raw)

*pix_ptr++ = get_data (alpha_file, alpha_depth);

else

if (alpha_depth <= 8)

*pix_ptr++ = get_value (alpha_file, bit_depth);

else

{

tmp16 = get_value (alpha_file, bit_depth);

*pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);

*pix_ptr++ = (png_byte) (tmp16 & 0xFF);

}

} /* if alpha */

} /* end for col */

} /* end for row */

/* prepare the standard PNG structures */

png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);

if (!png_ptr)

{

return FALSE;

}

info_ptr = png_create_info_struct (png_ptr);

if (!info_ptr)

{

png_destroy_write_struct (&png_ptr, (png_infopp) NULL);

return FALSE;

}

/* setjmp() must be called in every function that calls a PNG-reading libpng function */

if (setjmp (png_jmpbuf(png_ptr)))

{

png_destroy_write_struct (&png_ptr, (png_infopp) NULL);

return FALSE;

}

/* initialize the png structure */

png_init_io (png_ptr, png_file);

/* we're going to write more or less the same PNG as the input file */

png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,

(!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,

PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

/* write the file header information */

png_write_info (png_ptr, info_ptr);

/* if needed we will allocate memory for an new array of row-pointers */

if (row_pointers == (unsigned char**) NULL)

{

if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)

{

png_destroy_write_struct (&png_ptr, (png_infopp) NULL);

return FALSE;

}

}

/* set the individual row_pointers to point at the correct offsets */

for (i = 0; i < (height); i++)

row_pointers[i] = png_pixels + i * row_bytes;

/* write out the entire image data in one call */

png_write_image (png_ptr, row_pointers);

/* write the additional chuncks to the PNG file (not really needed) */

png_write_end (png_ptr, info_ptr);

/* clean up after the write, and free any memory allocated */

png_destroy_write_struct (&png_ptr, (png_infopp) NULL);

if (row_pointers != (unsigned char**) NULL)

free (row_pointers);

if (png_pixels != (unsigned char*) NULL)

free (png_pixels);

return TRUE;

} /* end of pnm2png */

/*

* get_token() - gets the first string after whitespace

*/

void get_token(FILE *pnm_file, char *token)

{

int i = 0;

/* remove white-space */

do

{

token[i] = (unsigned char) fgetc (pnm_file);

}

while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));

/* read string */

do

{

i++;

token[i] = (unsigned char) fgetc (pnm_file);

}

while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));

token[i] = '\0';

return;

}

/*

* get_data() - takes first byte and converts into next pixel value,

* taking as much bits as defined by bit-depth and

* using the bit-depth to fill up a byte (0Ah -> AAh)

*/

png_uint_32 get_data (FILE *pnm_file, int depth)

{

static int bits_left = 0;

static int old_value = 0;

static int mask = 0;

int i;

png_uint_32 ret_value;

if (mask == 0)

for (i = 0; i < depth; i++)

mask = (mask >> 1) | 0x80;

if (bits_left <= 0)

{

old_value = fgetc (pnm_file);

bits_left = 8;

}

ret_value = old_value & mask;

for (i = 1; i < (8 / depth); i++)

ret_value = ret_value || (ret_value >> depth);

old_value = (old_value << depth) & 0xFF;

bits_left -= depth;

return ret_value;

}

/*

* get_value() - takes first (numeric) string and converts into number,

* using the bit-depth to fill up a byte (0Ah -> AAh)

*/

png_uint_32 get_value (FILE *pnm_file, int depth)

{

static png_uint_32 mask = 0;

png_byte token[16];

png_uint_32 ret_value;

int i = 0;

if (mask == 0)

for (i = 0; i < depth; i++)

mask = (mask << 1) | 0x01;

get_token (pnm_file, (char *) token);

sscanf ((const char *) token, "%lu", &ret_value);

ret_value &= mask;

if (depth < 8)

for (i = 0; i < (8 / depth); i++)

ret_value = (ret_value << depth) || ret_value;

return ret_value;

}

/* end of source */