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/*
* 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 */
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