void convert2png(unsigned char ** buffer, FILE *outfile) {
ulg rowbytes;
int rc;
int nx = 800;
int ny = 600;
wpng_info.infile = NULL;
wpng_info.outfile = NULL;
wpng_info.image_data = NULL;
wpng_info.row_pointers = NULL;
wpng_info.filter = FALSE;
wpng_info.interlaced = FALSE;
wpng_info.have_bg = FALSE;
wpng_info.have_time = FALSE;
wpng_info.have_text = 0;
wpng_info.gamma = 0.0;
// input
wpng_info.outfile = outfile;
wpng_info.filter = TRUE;
wpng_info.width = nx;
wpng_info.height = ny;
wpng_info.pnmtype = 6;
wpng_info.have_bg = FALSE;
wpng_info.sample_depth = 8;
wpng_info.have_text = FALSE;
/* prepare the text buffers for libpng's use; note that even though
* PNG's png_text struct includes a length field, we don't have to fill
* it out */
rc = writepng_init(&wpng_info);
// wpng_info.pnmtype == 6
rowbytes = wpng_info.width * 3;
/* read and write the image, either in its entirety (if writing interlaced
* PNG) or row by row (if non-interlaced) */
fprintf(stderr, "Encoding image data...\n");
fflush(stderr);
long j;
wpng_info.infile = fopen("aU.ppm","rb");
wpng_info.image_data = (unsigned char *)malloc(rowbytes);
for (j = 0; j < wpng_info.height; j++) {
memcpy(wpng_info.image_data, buffer[j], rowbytes);
writepng_encode_row(&wpng_info);
}
writepng_encode_finish(&wpng_info);
fprintf(stderr, "Done.\n");
fflush(stderr);
writepng_cleanup(&wpng_info);
wpng_cleanup();
}
int main ( int argc, char **argv ) {
#ifndef DOS_OS2_W32
FILE *keybd;
#endif
#ifdef sgi
FILE *tmpfile; /* or we could just use keybd, since no overlap */
char tmpline[80];
#endif
char *inname = NULL, outname[256];
char *p, pnmchar, pnmline[256];
char *bgstr, *textbuf = NULL;
ulg rowbytes;
int rc, len = 0;
int error = 0;
int text = FALSE;
int maxval;
double LUT_exponent; /* just the lookup table */
double CRT_exponent = 2.2; /* just the monitor */
double default_display_exponent; /* whole display system */
double default_gamma = 0.0;
wpng_info.infile = NULL;
wpng_info.outfile = NULL;
wpng_info.image_data = NULL;
wpng_info.row_pointers = NULL;
wpng_info.filter = FALSE;
wpng_info.interlaced = FALSE;
wpng_info.have_bg = FALSE;
wpng_info.have_time = FALSE;
wpng_info.have_text = 0;
wpng_info.gamma = 0.0;
/* First get the default value for our display-system exponent, i.e.,
* the product of the CRT exponent and the exponent corresponding to
* the frame-buffer's lookup table (LUT), if any. If the PNM image
* looks correct on the user's display system, its file gamma is the
* inverse of this value. (Note that this is not an exhaustive list
* of LUT values--e.g., OpenStep has a lot of weird ones--but it should
* cover 99% of the current possibilities. This section must ensure
* that default_display_exponent is positive.) */
#if defined(NeXT)
/* third-party utilities can modify the default LUT exponent */
LUT_exponent = 1.0 / 2.2;
/*
if (some_next_function_that_returns_gamma(&next_gamma))
LUT_exponent = 1.0 / next_gamma;
*/
#elif defined(sgi)
LUT_exponent = 1.0 / 1.7;
/* there doesn't seem to be any documented function to
* get the "gamma" value, so we do it the hard way */
tmpfile = fopen ( "/etc/config/system.glGammaVal", "r" );
if ( tmpfile ) {
double sgi_gamma;
fgets ( tmpline, 80, tmpfile );
fclose ( tmpfile );
sgi_gamma = atof ( tmpline );
if ( sgi_gamma > 0.0 )
LUT_exponent = 1.0 / sgi_gamma;
}
#elif defined(Macintosh)
LUT_exponent = 1.8 / 2.61;
/*
if (some_mac_function_that_returns_gamma(&mac_gamma))
LUT_exponent = mac_gamma / 2.61;
*/
#else
LUT_exponent = 1.0; /* assume no LUT: most PCs */
#endif
/* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
default_display_exponent = LUT_exponent * CRT_exponent;
/* If the user has set the SCREEN_GAMMA environment variable as suggested
* (somewhat imprecisely) in the libpng documentation, use that; otherwise
* use the default value we just calculated. Either way, the user may
* override this via a command-line option. */
if ( ( p = getenv ( "SCREEN_GAMMA" ) ) != NULL ) {
double exponent = atof ( p );
if ( exponent > 0.0 )
default_gamma = 1.0 / exponent;
}
if ( default_gamma == 0.0 )
default_gamma = 1.0 / default_display_exponent;
/* Now parse the command line for options and the PNM filename. */
while ( *++argv && !error ) {
if ( !strncmp ( *argv, "-i", 2 ) ) {
wpng_info.interlaced = TRUE;
} else if ( !strncmp ( *argv, "-time", 3 ) ) {
wpng_info.modtime = time ( NULL );
wpng_info.have_time = TRUE;
} else if ( !strncmp ( *argv, "-text", 3 ) ) {
text = TRUE;
} else if ( !strncmp ( *argv, "-gamma", 2 ) ) {
if ( !*++argv )
++error;
else {
wpng_info.gamma = atof ( *argv );
if ( wpng_info.gamma <= 0.0 )
++error;
else if ( wpng_info.gamma > 1.01 )
fprintf ( stderr, PROGNAME
" warning: file gammas are usually less than 1.0\n" );
}
} else if ( !strncmp ( *argv, "-bgcolor", 4 ) ) {
if ( !*++argv )
++error;
else {
bgstr = *argv;
if ( strlen ( bgstr ) != 7 || bgstr[0] != '#' )
++error;
else {
unsigned r, g, b; /* this way quiets compiler warnings */
sscanf ( bgstr+1, "%2x%2x%2x", &r, &g, &b );
wpng_info.bg_red = ( uch ) r;
wpng_info.bg_green = ( uch ) g;
wpng_info.bg_blue = ( uch ) b;
wpng_info.have_bg = TRUE;
}
}
} else {
if ( **argv != '-' ) {
inname = *argv;
if ( argv[1] ) /* shouldn't be any more args after filename */
++error;
} else
++error; /* not expecting any other options */
}
}
/* open the input and output files, or register an error and abort */
if ( !inname ) {
if ( isatty ( 0 ) ) {
fprintf ( stderr, PROGNAME
": must give input filename or provide image data via stdin\n" );
++error;
} else {
#ifdef DOS_OS2_W32
/* some buggy C libraries require BOTH setmode() and fdopen(bin) */
setmode ( fileno ( stdin ), O_BINARY );
setmode ( fileno ( stdout ), O_BINARY );
#endif
if ( ( wpng_info.infile = fdopen ( fileno ( stdin ), "rb" ) ) == NULL ) {
fprintf ( stderr, PROGNAME
": unable to reopen stdin in binary mode\n" );
++error;
} else if ( ( wpng_info.outfile = fdopen ( fileno ( stdout ), "wb" ) ) == NULL ) {
fprintf ( stderr, PROGNAME
": unable to reopen stdout in binary mode\n" );
fclose ( wpng_info.infile );
++error;
} else
wpng_info.filter = TRUE;
}
} else if ( ( len = strlen ( inname ) ) > 250 ) {
fprintf ( stderr, PROGNAME ": input filename is too long [%d chars]\n",
len );
++error;
} else if ( ! ( wpng_info.infile = fopen ( inname, "rb" ) ) ) {
fprintf ( stderr, PROGNAME ": can't open input file [%s]\n", inname );
++error;
}
if ( !error ) {
fgets ( pnmline, 256, wpng_info.infile );
if ( pnmline[0] != 'P' || ( ( pnmchar = pnmline[1] ) != '5' &&
pnmchar != '6' && pnmchar != '8' ) ) {
fprintf ( stderr, PROGNAME
": input file [%s] is not a binary PGM, PPM or PAM file\n",
inname );
++error;
} else {
wpng_info.pnmtype = ( int ) ( pnmchar - '0' );
if ( wpng_info.pnmtype != 8 )
wpng_info.have_bg = FALSE; /* no need for bg if opaque */
do {
fgets ( pnmline, 256, wpng_info.infile ); /* lose any comments */
} while ( pnmline[0] == '#' );
sscanf ( pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height );
do {
fgets ( pnmline, 256, wpng_info.infile ); /* more comment lines */
} while ( pnmline[0] == '#' );
sscanf ( pnmline, "%d", &maxval );
if ( wpng_info.width <= 0L || wpng_info.height <= 0L ||
maxval != 255 ) {
fprintf ( stderr, PROGNAME
": only positive width/height, maxval == 255 allowed \n" );
++error;
}
wpng_info.sample_depth = 8; /* <==> maxval 255 */
if ( !wpng_info.filter ) {
/* make outname from inname */
if ( ( p = strrchr ( inname, '.' ) ) == NULL ||
( p - inname ) != ( len - 4 ) ) {
strcpy ( outname, inname );
strcpy ( outname+len, ".png" );
} else {
len -= 4;
strncpy ( outname, inname, len );
strcpy ( outname+len, ".png" );
}
/* check if outname already exists; if not, open */
if ( ( wpng_info.outfile = fopen ( outname, "rb" ) ) != NULL ) {
fprintf ( stderr, PROGNAME ": output file exists [%s]\n",
outname );
fclose ( wpng_info.outfile );
++error;
} else if ( ! ( wpng_info.outfile = fopen ( outname, "wb" ) ) ) {
fprintf ( stderr, PROGNAME ": can't open output file [%s]\n",
outname );
++error;
}
}
}
if ( error ) {
fclose ( wpng_info.infile );
wpng_info.infile = NULL;
if ( wpng_info.filter ) {
fclose ( wpng_info.outfile );
wpng_info.outfile = NULL;
}
}
}
/* if we had any errors, print usage and die horrible death...arrr! */
if ( error ) {
fprintf ( stderr, "\n%s %s: %s\n", PROGNAME, VERSION, APPNAME );
writepng_version_info();
fprintf ( stderr, "\n"
"Usage: %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n"
"or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n"
" exp \ttransfer-function exponent (``gamma'') of the image in\n"
"\t\t floating-point format (e.g., ``%.5f''); if image looks\n"
"\t\t correct on given display system, image gamma is equal to\n"
"\t\t inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n"
"\t\t (where LUT = lookup-table exponent and CRT = CRT exponent;\n"
"\t\t first varies, second is usually 2.2, all are positive)\n"
" bg \tdesired background color for alpha-channel images, in\n"
"\t\t 7-character hex RGB format (e.g., ``#ff7700'' for orange:\n"
"\t\t same as HTML colors)\n"
" -text\tprompt interactively for text info (tEXt chunks)\n"
" -time\tinclude a tIME chunk (last modification time)\n"
" -interlace\twrite interlaced PNG image\n"
"\n"
"pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n"
"unofficial and unsupported!) PAM (`P8') file. Currently it is required\n"
"to have maxval == 255 (i.e., no scaling). If pnmfile is specified, it\n"
"is converted to the corresponding PNG file with the same base name but a\n"
"``.png'' extension; files read from stdin are converted and sent to stdout.\n"
"The conversion is progressive (low memory usage) unless interlacing is\n"
"requested; in that case the whole image will be buffered in memory and\n"
"written in one call.\n"
"\n", PROGNAME, PROGNAME, default_gamma );
exit ( 1 );
}
/* prepare the text buffers for libpng's use; note that even though
* PNG's png_text struct includes a length field, we don't have to fill
* it out */
if ( text &&
#ifndef DOS_OS2_W32
( keybd = fdopen ( fileno ( stderr ), "r" ) ) != NULL &&
#endif
( textbuf = ( char * ) malloc ( ( 5 + 9 ) *75 ) ) != NULL ) {
int i, valid, result;
fprintf ( stderr,
"Enter text info (no more than 72 characters per line);\n" );
fprintf ( stderr, "to skip a field, hit the <Enter> key.\n" );
/* note: just <Enter> leaves len == 1 */
do {
valid = TRUE;
p = textbuf + TEXT_TITLE_OFFSET;
fprintf ( stderr, " Title: " );
fflush ( stderr );
if ( FGETS ( p, 74, keybd ) && ( len = strlen ( p ) ) > 1 ) {
if ( p[len-1] == '\n' )
p[--len] = '\0';
wpng_info.title = p;
wpng_info.have_text |= TEXT_TITLE;
if ( ( result = wpng_isvalid_latin1 ( ( uch * ) p, len ) ) >= 0 ) {
fprintf ( stderr, " " PROGNAME " warning: character code"
" %u is %sdiscouraged by the PNG\n specification "
"[first occurrence was at character position #%d]\n",
( unsigned ) p[result], ( p[result] == 27 ) ? "strongly " : "",
result+1 );
fflush ( stderr );
#ifdef FORBID_LATIN1_CTRL
wpng_info.have_text &= ~TEXT_TITLE;
valid = FALSE;
#else
if ( p[result] == 27 ) { /* escape character */
wpng_info.have_text &= ~TEXT_TITLE;
valid = FALSE;
}
#endif
}
}
} while ( !valid );
do {
valid = TRUE;
p = textbuf + TEXT_AUTHOR_OFFSET;
fprintf ( stderr, " Author: " );
fflush ( stderr );
if ( FGETS ( p, 74, keybd ) && ( len = strlen ( p ) ) > 1 ) {
if ( p[len-1] == '\n' )
p[--len] = '\0';
wpng_info.author = p;
wpng_info.have_text |= TEXT_AUTHOR;
if ( ( result = wpng_isvalid_latin1 ( ( uch * ) p, len ) ) >= 0 ) {
fprintf ( stderr, " " PROGNAME " warning: character code"
" %u is %sdiscouraged by the PNG\n specification "
"[first occurrence was at character position #%d]\n",
( unsigned ) p[result], ( p[result] == 27 ) ? "strongly " : "",
result+1 );
fflush ( stderr );
#ifdef FORBID_LATIN1_CTRL
wpng_info.have_text &= ~TEXT_AUTHOR;
valid = FALSE;
#else
if ( p[result] == 27 ) { /* escape character */
wpng_info.have_text &= ~TEXT_AUTHOR;
valid = FALSE;
}
#endif
}
}
} while ( !valid );
do {
valid = TRUE;
p = textbuf + TEXT_DESC_OFFSET;
fprintf ( stderr, " Description (up to 9 lines):\n" );
for ( i = 1; i < 10; ++i ) {
fprintf ( stderr, " [%d] ", i );
fflush ( stderr );
if ( FGETS ( p, 74, keybd ) && ( len = strlen ( p ) ) > 1 )
p += len; /* now points at NULL; char before is newline */
else
break;
}
if ( ( len = p - ( textbuf + TEXT_DESC_OFFSET ) ) > 1 ) {
if ( p[-1] == '\n' ) {
p[-1] = '\0';
--len;
}
wpng_info.desc = textbuf + TEXT_DESC_OFFSET;
wpng_info.have_text |= TEXT_DESC;
p = textbuf + TEXT_DESC_OFFSET;
if ( ( result = wpng_isvalid_latin1 ( ( uch * ) p, len ) ) >= 0 ) {
fprintf ( stderr, " " PROGNAME " warning: character code"
" %u is %sdiscouraged by the PNG\n specification "
"[first occurrence was at character position #%d]\n",
( unsigned ) p[result], ( p[result] == 27 ) ? "strongly " : "",
result+1 );
fflush ( stderr );
#ifdef FORBID_LATIN1_CTRL
wpng_info.have_text &= ~TEXT_DESC;
valid = FALSE;
#else
if ( p[result] == 27 ) { /* escape character */
wpng_info.have_text &= ~TEXT_DESC;
valid = FALSE;
}
#endif
}
}
} while ( !valid );
do {
valid = TRUE;
p = textbuf + TEXT_COPY_OFFSET;
fprintf ( stderr, " Copyright: " );
fflush ( stderr );
if ( FGETS ( p, 74, keybd ) && ( len = strlen ( p ) ) > 1 ) {
if ( p[len-1] == '\n' )
p[--len] = '\0';
wpng_info.copyright = p;
wpng_info.have_text |= TEXT_COPY;
if ( ( result = wpng_isvalid_latin1 ( ( uch * ) p, len ) ) >= 0 ) {
fprintf ( stderr, " " PROGNAME " warning: character code"
" %u is %sdiscouraged by the PNG\n specification "
"[first occurrence was at character position #%d]\n",
( unsigned ) p[result], ( p[result] == 27 ) ? "strongly " : "",
result+1 );
fflush ( stderr );
#ifdef FORBID_LATIN1_CTRL
wpng_info.have_text &= ~TEXT_COPY;
valid = FALSE;
#else
if ( p[result] == 27 ) { /* escape character */
wpng_info.have_text &= ~TEXT_COPY;
valid = FALSE;
}
#endif
}
}
} while ( !valid );
do {
valid = TRUE;
p = textbuf + TEXT_EMAIL_OFFSET;
fprintf ( stderr, " E-mail: " );
fflush ( stderr );
if ( FGETS ( p, 74, keybd ) && ( len = strlen ( p ) ) > 1 ) {
if ( p[len-1] == '\n' )
p[--len] = '\0';
wpng_info.email = p;
wpng_info.have_text |= TEXT_EMAIL;
if ( ( result = wpng_isvalid_latin1 ( ( uch * ) p, len ) ) >= 0 ) {
fprintf ( stderr, " " PROGNAME " warning: character code"
" %u is %sdiscouraged by the PNG\n specification "
"[first occurrence was at character position #%d]\n",
( unsigned ) p[result], ( p[result] == 27 ) ? "strongly " : "",
result+1 );
fflush ( stderr );
#ifdef FORBID_LATIN1_CTRL
wpng_info.have_text &= ~TEXT_EMAIL;
valid = FALSE;
#else
if ( p[result] == 27 ) { /* escape character */
wpng_info.have_text &= ~TEXT_EMAIL;
valid = FALSE;
}
#endif
}
}
} while ( !valid );
do {
valid = TRUE;
p = textbuf + TEXT_URL_OFFSET;
fprintf ( stderr, " URL: " );
fflush ( stderr );
if ( FGETS ( p, 74, keybd ) && ( len = strlen ( p ) ) > 1 ) {
if ( p[len-1] == '\n' )
p[--len] = '\0';
wpng_info.url = p;
wpng_info.have_text |= TEXT_URL;
if ( ( result = wpng_isvalid_latin1 ( ( uch * ) p, len ) ) >= 0 ) {
fprintf ( stderr, " " PROGNAME " warning: character code"
" %u is %sdiscouraged by the PNG\n specification "
"[first occurrence was at character position #%d]\n",
( unsigned ) p[result], ( p[result] == 27 ) ? "strongly " : "",
result+1 );
fflush ( stderr );
#ifdef FORBID_LATIN1_CTRL
wpng_info.have_text &= ~TEXT_URL;
valid = FALSE;
#else
if ( p[result] == 27 ) { /* escape character */
wpng_info.have_text &= ~TEXT_URL;
valid = FALSE;
}
#endif
}
}
} while ( !valid );
#ifndef DOS_OS2_W32
fclose ( keybd );
#endif
} else if ( text ) {
fprintf ( stderr, PROGNAME ": unable to allocate memory for text\n" );
text = FALSE;
wpng_info.have_text = 0;
}
/* allocate libpng stuff, initialize transformations, write pre-IDAT data */
if ( ( rc = writepng_init ( &wpng_info ) ) != 0 ) {
switch ( rc ) {
case 2:
fprintf ( stderr, PROGNAME
": libpng initialization problem (longjmp)\n" );
break;
case 4:
fprintf ( stderr, PROGNAME ": insufficient memory\n" );
break;
case 11:
fprintf ( stderr, PROGNAME
": internal logic error (unexpected PNM type)\n" );
break;
default:
fprintf ( stderr, PROGNAME
": unknown writepng_init() error\n" );
break;
}
exit ( rc );
}
/* free textbuf, since it's a completely local variable and all text info
* has just been written to the PNG file */
if ( text && textbuf ) {
free ( textbuf );
textbuf = NULL;
}
/* calculate rowbytes on basis of image type; note that this becomes much
* more complicated if we choose to support PBM type, ASCII PNM types, or
* 16-bit-per-sample binary data [currently not an official NetPBM type] */
if ( wpng_info.pnmtype == 5 )
rowbytes = wpng_info.width;
else if ( wpng_info.pnmtype == 6 )
rowbytes = wpng_info.width * 3;
else /* if (wpng_info.pnmtype == 8) */
rowbytes = wpng_info.width * 4;
/* read and write the image, either in its entirety (if writing interlaced
* PNG) or row by row (if non-interlaced) */
fprintf ( stderr, "Encoding image data...\n" );
fflush ( stderr );
if ( wpng_info.interlaced ) {
long i;
ulg bytes;
ulg image_bytes = rowbytes * wpng_info.height; /* overflow? */
wpng_info.image_data = ( uch * ) malloc ( image_bytes );
wpng_info.row_pointers = ( uch ** ) malloc ( wpng_info.height*sizeof ( uch * ) );
if ( wpng_info.image_data == NULL || wpng_info.row_pointers == NULL ) {
fprintf ( stderr, PROGNAME ": insufficient memory for image data\n" );
writepng_cleanup ( &wpng_info );
wpng_cleanup();
exit ( 5 );
}
for ( i = 0; i < wpng_info.height; ++i )
wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes;
bytes = fread ( wpng_info.image_data, 1, image_bytes, wpng_info.infile );
if ( bytes != image_bytes ) {
fprintf ( stderr, PROGNAME ": expected %lu bytes, got %lu bytes\n",
image_bytes, bytes );
fprintf ( stderr, " (continuing anyway)\n" );
}
if ( writepng_encode_image ( &wpng_info ) != 0 ) {
fprintf ( stderr, PROGNAME
": libpng problem (longjmp) while writing image data\n" );
writepng_cleanup ( &wpng_info );
wpng_cleanup();
exit ( 2 );
}
} else { /* not interlaced: write progressively (row by row) */
long j;
ulg bytes;
wpng_info.image_data = ( uch * ) malloc ( rowbytes );
if ( wpng_info.image_data == NULL ) {
fprintf ( stderr, PROGNAME ": insufficient memory for row data\n" );
writepng_cleanup ( &wpng_info );
wpng_cleanup();
exit ( 5 );
}
error = 0;
for ( j = wpng_info.height; j > 0L; --j ) {
bytes = fread ( wpng_info.image_data, 1, rowbytes, wpng_info.infile );
if ( bytes != rowbytes ) {
fprintf ( stderr, PROGNAME
": expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes,
bytes, wpng_info.height-j );
++error;
break;
}
if ( writepng_encode_row ( &wpng_info ) != 0 ) {
fprintf ( stderr, PROGNAME
": libpng problem (longjmp) while writing row %ld\n",
wpng_info.height-j );
++error;
break;
}
}
if ( error ) {
writepng_cleanup ( &wpng_info );
wpng_cleanup();
exit ( 2 );
}
if ( writepng_encode_finish ( &wpng_info ) != 0 ) {
fprintf ( stderr, PROGNAME ": error on final libpng call\n" );
writepng_cleanup ( &wpng_info );
wpng_cleanup();
exit ( 2 );
}
}
/* OK, we're done (successfully): clean up all resources and quit */
fprintf ( stderr, "Done.\n" );
fflush ( stderr );
writepng_cleanup ( &wpng_info );
wpng_cleanup();
return 0;
}
void write_ppm2png(FILE *infile, FILE *outfile) {
char pnmline[256];
ulg rowbytes;
int rc;
wpng_info.infile = NULL;
wpng_info.outfile = NULL;
wpng_info.image_data = NULL;
wpng_info.row_pointers = NULL;
wpng_info.filter = FALSE;
wpng_info.interlaced = FALSE;
wpng_info.have_bg = FALSE;
wpng_info.have_time = FALSE;
wpng_info.have_text = 0;
wpng_info.gamma = 0.0;
// input
wpng_info.infile = infile;
wpng_info.outfile = outfile;
wpng_info.filter = TRUE;
wpng_info.width = 800;
wpng_info.height = 600;
wpng_info.pnmtype = 6;
wpng_info.have_bg = FALSE;
wpng_info.sample_depth = 8;
wpng_info.have_text = FALSE;
fgets(pnmline, 256, wpng_info.infile);
do {
fgets(pnmline, 256, wpng_info.infile); /* lose any comments */
} while (pnmline[0] == '#');
do {
fgets(pnmline, 256, wpng_info.infile); /* more comment lines */
} while (pnmline[0] == '#');
/* prepare the text buffers for libpng's use; note that even though
* PNG's png_text struct includes a length field, we don't have to fill
* it out */
rc = writepng_init(&wpng_info);
// wpng_info.pnmtype == 6
rowbytes = wpng_info.width * 3;
/* read and write the image, either in its entirety (if writing interlaced
* PNG) or row by row (if non-interlaced) */
fprintf(stderr, "Encoding image data...\n");
fflush(stderr);
long j;
wpng_info.image_data = (uch *)malloc(rowbytes);
for (j = wpng_info.height; j > 0L; --j) {
fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile);
writepng_encode_row(&wpng_info);
}
writepng_encode_finish(&wpng_info);
fprintf(stderr, "Done.\n");
fflush(stderr);
writepng_cleanup(&wpng_info);
wpng_cleanup();
}