| /* |
| * pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file |
| * copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot com> |
| * |
| * This software is released under the MIT license. For conditions of |
| * distribution and use, see the LICENSE file part of this package. |
| */ |
| |
| #include <limits.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <fcntl.h> |
| |
| #ifndef BOOL |
| #define BOOL unsigned char |
| #endif |
| #ifndef TRUE |
| #define TRUE ((BOOL) 1) |
| #endif |
| #ifndef FALSE |
| #define FALSE ((BOOL) 0) |
| #endif |
| |
| #include "png.h" |
| |
| /* 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); |
| BOOL do_pnm2png (png_struct *png_ptr, png_info *info_ptr, |
| FILE *pnm_file, FILE *alpha_file, |
| BOOL interlace, BOOL alpha); |
| int fscan_pnm_magic (FILE *pnm_file, char *magic_buf, size_t magic_buf_size); |
| int fscan_pnm_token (FILE *pnm_file, char *token_buf, size_t token_buf_size); |
| int fscan_pnm_uint_32 (FILE *pnm_file, png_uint_32 *num_ptr); |
| png_uint_32 get_pnm_data (FILE *pnm_file, int depth); |
| png_uint_32 get_pnm_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; |
| const char *fname_wr = NULL; |
| BOOL interlace = FALSE; |
| BOOL alpha = FALSE; |
| int argi; |
| int ret; |
| |
| 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) |
| { |
| fname_wr = argv[argi]; |
| if ((fp_wr = fopen (argv[argi], "wb")) == NULL) |
| { |
| fprintf (stderr, "PNM2PNG\n"); |
| fprintf (stderr, "Error: cannot 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 */ |
| |
| #if defined(O_BINARY) && (O_BINARY != 0) |
| /* set stdin/stdout to binary, |
| * we're reading the PNM always! in binary format |
| */ |
| if (fp_rd == stdin) |
| setmode (fileno (stdin), O_BINARY); |
| if (fp_wr == stdout) |
| setmode (fileno (stdout), O_BINARY); |
| #endif |
| |
| /* call the conversion program itself */ |
| ret = pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha); |
| |
| /* close input file */ |
| fclose (fp_rd); |
| /* close output file */ |
| fclose (fp_wr); |
| /* close alpha file */ |
| if (alpha) |
| fclose (fp_al); |
| |
| if (!ret) |
| { |
| fprintf (stderr, "PNM2PNG\n"); |
| fprintf (stderr, "Error: unsuccessful converting to PNG-image\n"); |
| if (fname_wr) |
| remove (fname_wr); /* no broken output file shall remain behind */ |
| exit (1); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * usage |
| */ |
| |
| void usage () |
| { |
| fprintf (stderr, "PNM2PNG\n"); |
| fprintf (stderr, " by Willem van Schaik, 1999\n"); |
| 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; |
| png_info *info_ptr; |
| BOOL ret; |
| |
| /* initialize the libpng context for writing to png_file */ |
| |
| png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), |
| NULL, NULL, NULL); |
| if (!png_ptr) |
| return FALSE; /* out of memory */ |
| |
| info_ptr = png_create_info_struct (png_ptr); |
| if (!info_ptr) |
| { |
| png_destroy_write_struct (&png_ptr, NULL); |
| return FALSE; /* out of memory */ |
| } |
| |
| if (setjmp (png_jmpbuf (png_ptr))) |
| { |
| png_destroy_write_struct (&png_ptr, &info_ptr); |
| return FALSE; /* generic libpng error */ |
| } |
| |
| png_init_io (png_ptr, png_file); |
| |
| /* do the actual conversion */ |
| ret = do_pnm2png (png_ptr, info_ptr, pnm_file, alpha_file, interlace, alpha); |
| |
| /* clean up the libpng structures and their internally-managed data */ |
| png_destroy_write_struct (&png_ptr, &info_ptr); |
| |
| return ret; |
| } |
| |
| /* |
| * do_pnm2png - does the conversion in a fully-initialized libpng context |
| */ |
| |
| BOOL do_pnm2png (png_struct *png_ptr, png_info *info_ptr, |
| FILE *pnm_file, FILE *alpha_file, |
| BOOL interlace, BOOL alpha) |
| { |
| png_byte **row_pointers; |
| png_byte *pix_ptr; |
| int bit_depth; |
| int color_type; |
| int channels; |
| char magic_token[4]; |
| BOOL raw; |
| png_uint_32 width, height, maxval; |
| png_uint_32 row_bytes; |
| png_uint_32 row, col; |
| png_uint_32 val16, i; |
| png_uint_32 alpha_width = 0, alpha_height = 0; |
| int alpha_depth = 0, alpha_present = 0; |
| BOOL alpha_raw = FALSE; |
| BOOL packed_bitmap = FALSE; |
| |
| /* read header of PNM file */ |
| |
| if (fscan_pnm_magic (pnm_file, magic_token, sizeof (magic_token)) != 1) |
| return FALSE; /* not a PNM file */ |
| |
| if ((magic_token[1] == '1') || (magic_token[1] == '4')) |
| { |
| if ((fscan_pnm_uint_32 (pnm_file, &width) != 1) || |
| (fscan_pnm_uint_32 (pnm_file, &height) != 1)) |
| return FALSE; /* bad PBM file header */ |
| } else if ((magic_token[1] == '2') || (magic_token[1] == '5') || |
| (magic_token[1] == '3') || (magic_token[1] == '6')) |
| { |
| if ((fscan_pnm_uint_32 (pnm_file, &width) != 1) || |
| (fscan_pnm_uint_32 (pnm_file, &height) != 1) || |
| (fscan_pnm_uint_32 (pnm_file, &maxval) != 1)) |
| return FALSE; /* bad PGM/PPM file header */ |
| } |
| |
| if ((magic_token[1] == '1') || (magic_token[1] == '4')) |
| { |
| raw = (magic_token[1] == '4'); |
| bit_depth = 1; |
| color_type = PNG_COLOR_TYPE_GRAY; |
| packed_bitmap = TRUE; |
| } |
| else if ((magic_token[1] == '2') || (magic_token[1] == '5')) |
| { |
| raw = (magic_token[1] == '5'); |
| color_type = PNG_COLOR_TYPE_GRAY; |
| if (maxval == 0) |
| return FALSE; |
| else 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 <= 65535U) |
| bit_depth = 16; |
| else /* maxval > 65535U */ |
| return FALSE; |
| } |
| else if ((magic_token[1] == '3') || (magic_token[1] == '6')) |
| { |
| raw = (magic_token[1] == '6'); |
| color_type = PNG_COLOR_TYPE_RGB; |
| if (maxval == 0) |
| return FALSE; |
| else 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 <= 65535U) |
| bit_depth = 16; |
| else /* maxval > 65535U */ |
| return FALSE; |
| } |
| else if (magic_token[1] == '7') |
| { |
| fprintf (stderr, "PNM2PNG can't read PAM (P7) files\n"); |
| return FALSE; |
| } |
| else |
| { |
| return FALSE; |
| } |
| |
| /* read header of PGM file with alpha channel */ |
| |
| if (alpha) |
| { |
| if ((fscan_pnm_magic (alpha_file, magic_token, sizeof (magic_token)) != 1) |
| || ((magic_token[1] != '2') && (magic_token[1] != '5'))) |
| return FALSE; /* not a PGM file */ |
| |
| if ((fscan_pnm_uint_32 (alpha_file, &alpha_width) != 1) || |
| (fscan_pnm_uint_32 (alpha_file, &alpha_height) != 1) || |
| (fscan_pnm_uint_32 (alpha_file, &maxval) != 1)) |
| return FALSE; /* bad PGM file header */ |
| |
| if ((alpha_width != width) || (alpha_height != height)) |
| return FALSE; /* mismatched PGM dimensions */ |
| |
| alpha_raw = (magic_token[1] == '5'); |
| color_type |= PNG_COLOR_MASK_ALPHA; |
| if (maxval == 0) |
| return FALSE; |
| else 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 <= 65535U) |
| alpha_depth = 16; |
| else /* maxval > 65535U */ |
| return FALSE; |
| if (alpha_depth != bit_depth) |
| 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 |
| return FALSE; /* NOTREACHED */ |
| |
| alpha_present = (channels - 1) % 2; |
| |
| if (packed_bitmap) |
| { |
| /* row data is as many bytes as can fit width x channels x bit_depth */ |
| row_bytes = (width * channels * bit_depth + 7) / 8; |
| } |
| else |
| { |
| /* row_bytes is the width x number of channels x (bit-depth / 8) */ |
| row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2); |
| } |
| |
| if ((row_bytes == 0) || |
| ((size_t) height > (size_t) (-1) / (size_t) row_bytes)) |
| { |
| /* too big */ |
| return FALSE; |
| } |
| |
| /* allocate the rows using the same memory layout as libpng, and transfer |
| * their ownership to libpng, with the responsibility to clean everything up; |
| * please note the use of png_calloc instead of png_malloc */ |
| row_pointers = (png_byte **) |
| png_calloc (png_ptr, height * sizeof (png_byte *)); |
| png_set_rows (png_ptr, info_ptr, row_pointers); |
| png_data_freer (png_ptr, info_ptr, PNG_DESTROY_WILL_FREE_DATA, PNG_FREE_ALL); |
| for (row = 0; row < height; row++) |
| { |
| /* the individual rows should only be allocated after all the previous |
| * steps completed successfully, because libpng must handle correctly |
| * any image allocation left incomplete after an out-of-memory error */ |
| row_pointers[row] = (png_byte *) png_malloc (png_ptr, row_bytes); |
| } |
| |
| /* read the data from PNM file */ |
| |
| for (row = 0; row < height; row++) |
| { |
| pix_ptr = row_pointers[row]; |
| if (packed_bitmap) |
| { |
| for (i = 0; i < row_bytes; i++) |
| { |
| /* png supports this format natively so no conversion is needed */ |
| *pix_ptr++ = get_pnm_data (pnm_file, 8); |
| } |
| } |
| else |
| { |
| for (col = 0; col < width; col++) |
| { |
| for (i = 0; i < (png_uint_32) (channels - alpha_present); i++) |
| { |
| if (raw) |
| { |
| *pix_ptr++ = get_pnm_data (pnm_file, bit_depth); |
| if (bit_depth == 16) |
| *pix_ptr++ = get_pnm_data (pnm_file, bit_depth); |
| } |
| else |
| { |
| if (bit_depth <= 8) |
| { |
| *pix_ptr++ = get_pnm_value (pnm_file, bit_depth); |
| } |
| else |
| { |
| val16 = get_pnm_value (pnm_file, bit_depth); |
| *pix_ptr = (png_byte) ((val16 >> 8) & 0xFF); |
| pix_ptr++; |
| *pix_ptr = (png_byte) (val16 & 0xFF); |
| pix_ptr++; |
| } |
| } |
| } |
| |
| if (alpha) /* read alpha-channel from pgm file */ |
| { |
| if (alpha_raw) |
| { |
| *pix_ptr++ = get_pnm_data (alpha_file, alpha_depth); |
| if (alpha_depth == 16) |
| *pix_ptr++ = get_pnm_data (alpha_file, alpha_depth); |
| } |
| else |
| { |
| if (alpha_depth <= 8) |
| { |
| *pix_ptr++ = get_pnm_value (alpha_file, bit_depth); |
| } |
| else |
| { |
| val16 = get_pnm_value (alpha_file, bit_depth); |
| *pix_ptr++ = (png_byte) ((val16 >> 8) & 0xFF); |
| *pix_ptr++ = (png_byte) (val16 & 0xFF); |
| } |
| } |
| } /* end if alpha */ |
| } /* end if packed_bitmap */ |
| } /* end for col */ |
| } /* end for row */ |
| |
| /* 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); |
| |
| if (packed_bitmap == TRUE) |
| { |
| png_set_packing (png_ptr); |
| png_set_invert_mono (png_ptr); |
| } |
| |
| /* write the file header information */ |
| png_write_info (png_ptr, info_ptr); |
| |
| /* write out the entire image data in one call */ |
| png_write_image (png_ptr, row_pointers); |
| |
| /* write the additional chunks to the PNG file (not really needed) */ |
| png_write_end (png_ptr, info_ptr); |
| |
| return TRUE; |
| } /* end of pnm2png */ |
| |
| /* |
| * fscan_pnm_magic - like fscan_pnm_token below, but expects the magic string |
| * to start immediately, without any comment or whitespace, |
| * and to match the regex /^P[1-9]$/ |
| */ |
| |
| int fscan_pnm_magic (FILE *pnm_file, char *magic_buf, size_t magic_buf_size) |
| { |
| int ret; |
| |
| ret = fgetc (pnm_file); |
| if (ret == EOF) return 0; |
| ungetc (ret, pnm_file); |
| if (ret != 'P') return 0; |
| |
| /* the string buffer must be at least four bytes long, i.e., the capacity |
| * required for strings of at least three characters long, i.e., the minimum |
| * required for ensuring that our magic string is exactly two characters long |
| */ |
| if (magic_buf_size < 4) return -1; |
| |
| ret = fscan_pnm_token (pnm_file, magic_buf, magic_buf_size); |
| if (ret < 1) return ret; |
| |
| if ((magic_buf[1] < '1') || (magic_buf[1] > '9')) return 0; |
| if (magic_buf[2] != '\0') return 0; |
| |
| return 1; |
| } |
| |
| /* |
| * fscan_pnm_token - extracts the first string token after whitespace, |
| * and (like fscanf) returns the number of successful |
| * extractions, which can be either 0 or 1 |
| */ |
| |
| int fscan_pnm_token (FILE *pnm_file, char *token_buf, size_t token_buf_size) |
| { |
| size_t i = 0; |
| int ret; |
| |
| /* remove white-space and comment lines */ |
| do |
| { |
| ret = fgetc (pnm_file); |
| if (ret == '#') |
| { |
| /* the rest of this line is a comment */ |
| do |
| { |
| ret = fgetc (pnm_file); |
| } |
| while ((ret != '\n') && (ret != '\r') && (ret != EOF)); |
| } |
| if (ret == EOF) break; |
| token_buf[i] = (char) ret; |
| } |
| while ((ret == '\n') || (ret == '\r') || (ret == ' ')); |
| |
| /* read string */ |
| do |
| { |
| ret = fgetc (pnm_file); |
| if (ret == EOF) break; |
| if (ret == '0') |
| { |
| /* avoid storing more than one leading '0' in the token buffer, |
| * to ensure that all valid (in-range) numeric inputs can fit in. */ |
| if ((i == 0) && (token_buf[i] == '0')) continue; |
| } |
| if (++i == token_buf_size - 1) break; |
| token_buf[i] = (char) ret; |
| } |
| while ((ret != '\n') && (ret != '\r') && (ret != ' ')); |
| |
| token_buf[i] = '\0'; |
| return (i > 0) ? 1 : 0; |
| } |
| |
| /* |
| * fscan_pnm_uint_32 - like fscan_token above, but expects the extracted token |
| * to be numeric, and converts it to an unsigned 32-bit int |
| */ |
| |
| int fscan_pnm_uint_32 (FILE *pnm_file, png_uint_32 *num_ptr) |
| { |
| char token[16]; |
| unsigned long token_value; |
| int ret; |
| |
| ret = fscan_pnm_token (pnm_file, token, sizeof (token)); |
| if (ret < 1) return ret; |
| |
| if ((token[0] < '0') && (token[0] > '9')) |
| return 0; /* the token starts with junk, or a +/- sign, which is invalid */ |
| |
| ret = sscanf (token, "%lu%*c", &token_value); |
| if (ret != 1) |
| return 0; /* the token ends with junk */ |
| |
| *num_ptr = (png_uint_32) token_value; |
| |
| #if ULONG_MAX > 0xFFFFFFFFUL |
| /* saturate the converted number, following the fscanf convention */ |
| if (token_value > 0xFFFFFFFFUL) |
| *num_ptr = 0xFFFFFFFFUL; |
| #endif |
| |
| return 1; |
| } |
| |
| /* |
| * get_pnm_data - takes first byte and converts into next pixel value, |
| * taking as many bits as defined by bit-depth and |
| * using the bit-depth to fill up a byte (0x0A -> 0xAA) |
| */ |
| |
| png_uint_32 get_pnm_data (FILE *pnm_file, int depth) |
| { |
| static int bits_left = 0; |
| static int old_value = 0; |
| static int mask = 0; |
| png_uint_32 ret_value; |
| int i; |
| |
| if (mask == 0) |
| for (i = 0; i < depth; i++) |
| mask = (mask >> 1) | 0x80; |
| |
| if (bits_left <= 0) |
| { |
| /* FIXME: |
| * signal the premature end of file, instead of pretending to read zeroes |
| */ |
| old_value = fgetc (pnm_file); |
| if (old_value == EOF) return 0; |
| 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_pnm_value - takes first (numeric) string and converts into number, |
| * using the bit-depth to fill up a byte (0x0A -> 0xAA) |
| */ |
| |
| png_uint_32 get_pnm_value (FILE *pnm_file, int depth) |
| { |
| static png_uint_32 mask = 0; |
| png_uint_32 ret_value; |
| int i; |
| |
| if (mask == 0) |
| for (i = 0; i < depth; i++) |
| mask = (mask << 1) | 0x01; |
| |
| if (fscan_pnm_uint_32 (pnm_file, &ret_value) != 1) |
| { |
| /* FIXME: |
| * signal the invalid numeric tokens or the premature end of file, |
| * instead of pretending to read zeroes |
| */ |
| return 0; |
| } |
| |
| 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 */ |
