520 lines
9.8 KiB
C
520 lines
9.8 KiB
C
/* Read a ppm file.
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*
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* Stephen Chan ... original code
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*
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* 21/11/00 JC
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* - hacked for VIPS
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* - reads ppm/pgm/pbm
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* - mmaps binary pgm/ppm
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* - reads all ascii formats (slowly!)
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* 22/11/00 JC
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* - oops, ascii read was broken
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* - does 16/32 bit ascii now as well
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* 24/5/01
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* - im_ppm2vips_header() added
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* 22/5/04
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* - does 16/32 bit binary too
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* - tiny fix for missing file close on read error
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* 19/8/05
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* - use im_raw2vips() for binary read
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* 9/9/05
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* - tiny cleanups
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*/
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/*
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This file is part of VIPS.
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VIPS is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/*
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These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif /*HAVE_CONFIG_H*/
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#include <vips/intl.h>
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#include <ctype.h>
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#include <stdio.h>
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#include <assert.h>
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#include <string.h>
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#include <stdlib.h>
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#include <vips/vips.h>
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#include <vips/internal.h>
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#ifdef WITH_DMALLOC
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#include <dmalloc.h>
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#endif /*WITH_DMALLOC*/
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/* The largest number/field/whatever we can read.
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*/
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#define IM_MAX_THING (80)
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static void
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skip_line( FILE *fp )
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{
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int ch;
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while( (ch = fgetc( fp )) != '\n' )
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;
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}
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static void
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skip_white_space( FILE *fp )
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{
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int ch;
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while( isspace( ch = fgetc( fp ) ) )
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;
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ungetc( ch, fp );
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if( ch == '#' ) {
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skip_line( fp );
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skip_white_space( fp );
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}
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}
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static int
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read_uint( FILE *fp )
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{
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int i;
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char buf[IM_MAX_THING];
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int ch;
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skip_white_space( fp );
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/* Stop complaints about used-before-set on ch.
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*/
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ch = -1;
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for( i = 0; i < IM_MAX_THING - 1 && isdigit( ch = fgetc( fp ) ); i++ )
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buf[i] = ch;
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buf[i] = '\0';
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if( i == 0 ) {
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im_error( "im_ppm2vips", _( "bad unsigned int" ) );
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return( -1 );
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}
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ungetc( ch, fp );
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return( atoi( buf ) );
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}
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static int
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read_header( FILE *fp, IMAGE *out, int *bits, int *ascii )
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{
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int width, height, bands, fmt, type;
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int i;
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char buf[IM_MAX_THING];
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int max_value;
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/* ppm types.
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*/
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static char *magic_names[] = {
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"P1", /* pbm ... 1 band 1 bit, ascii */
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"P2", /* pgm ... 1 band many bit, ascii */
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"P3", /* ppm ... 3 band many bit, ascii */
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"P4", /* pbm ... 1 band 1 bit, binary */
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"P5", /* pgm ... 1 band 8 bit, binary */
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"P6" /* ppm ... 3 band 8 bit, binary */
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};
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/* Characteristics, indexed by ppm type.
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*/
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static int lookup_bits[] = {
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1, 8, 8, 1, 8, 8
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};
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static int lookup_bands[] = {
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1, 1, 3, 1, 1, 3
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};
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static int lookup_ascii[] = {
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1, 1, 1, 0, 0, 0
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};
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/* Read in the magic number.
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*/
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buf[0] = fgetc( fp );
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buf[1] = fgetc( fp );
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buf[2] = '\0';
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for( i = 0; i < IM_NUMBER( magic_names ); i++ )
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if( strcmp( magic_names[i], buf ) == 0 )
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break;
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if( i == IM_NUMBER( magic_names ) ) {
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im_error( "im_ppm2vips", _( "bad magic number" ) );
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return( -1 );
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}
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*bits = lookup_bits[i];
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bands = lookup_bands[i];
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*ascii = lookup_ascii[i];
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/* Read in size.
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*/
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if( (width = read_uint( fp )) < 0 ||
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(height = read_uint( fp )) < 0 )
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return( -1 );
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/* Read in max value for >1 bit images.
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*/
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if( *bits > 1 ) {
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if( (max_value = read_uint( fp )) < 0 )
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return( -1 );
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if( max_value > 255 )
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*bits = 16;
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if( max_value > 65535 )
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*bits = 32;
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}
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/* For binary images, there is always exactly 1 more whitespace
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* character before the data starts.
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*/
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if( !*ascii && !isspace( fgetc( fp ) ) ) {
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im_error( "im_ppm2vips",
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_( "not whitespace before start of binary data" ) );
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return( -1 );
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}
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/* Choose a VIPS bandfmt.
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*/
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switch( *bits ) {
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case 1:
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case 8:
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fmt = IM_BANDFMT_UCHAR;
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break;
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case 16:
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fmt = IM_BANDFMT_USHORT;
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break;
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case 32:
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fmt = IM_BANDFMT_UINT;
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break;
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default:
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assert( 0 );
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}
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if( bands == 1 ) {
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if( fmt == IM_BANDFMT_USHORT )
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type = IM_TYPE_GREY16;
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else
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type = IM_TYPE_B_W;
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}
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else {
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if( fmt == IM_BANDFMT_USHORT )
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type = IM_TYPE_RGB16;
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else if( fmt == IM_BANDFMT_UINT )
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type = IM_TYPE_RGB;
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else
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type = IM_TYPE_sRGB;
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}
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im_initdesc( out, width, height, bands, (*bits == 1) ? 8 : *bits, fmt,
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IM_CODING_NONE,
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type,
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1.0, 1.0,
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0, 0 );
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return( 0 );
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}
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/* Read a ppm/pgm file using mmap().
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*/
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static int
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read_mmap( FILE *fp, const char *filename, IMAGE *out )
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{
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const int header_offset = ftell( fp );
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IMAGE *t[2];
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im_arch_type arch = im_amiMSBfirst() ?
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IM_ARCH_NATIVE : IM_ARCH_BYTE_SWAPPED;
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if( im_open_local_array( out, t, 2, "im_ppm2vips", "p" ) ||
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im_raw2vips( filename, t[0],
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out->Xsize, out->Ysize,
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IM_IMAGE_SIZEOF_PEL( out ), header_offset ) ||
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im_copy_morph( t[0], t[1],
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out->Bands, out->BandFmt, out->Coding ) ||
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im_copy_from( t[1], out, arch ) )
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return( -1 );
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return( 0 );
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}
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/* Read an ascii ppm/pgm file.
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*/
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static int
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read_ascii( FILE *fp, IMAGE *out )
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{
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int x, y;
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PEL *buf;
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if( im_outcheck( out ) || im_setupout( out ) ||
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!(buf = IM_ARRAY( out, IM_IMAGE_SIZEOF_LINE( out ), PEL )) )
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return( -1 );
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for( y = 0; y < out->Ysize; y++ ) {
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for( x = 0; x < out->Xsize * out->Bands; x++ ) {
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int val;
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if( (val = read_uint( fp )) < 0 )
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return( -1 );
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switch( out->BandFmt ) {
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case IM_BANDFMT_UCHAR:
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buf[x] = IM_CLIP( 0, val, 255 );
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break;
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case IM_BANDFMT_USHORT:
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((unsigned short *) buf)[x] =
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IM_CLIP( 0, val, 65535 );
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break;
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case IM_BANDFMT_UINT:
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((unsigned int *) buf)[x] = val;
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break;
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default:
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assert( 0 );
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}
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}
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if( im_writeline( y, out, buf ) )
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return( -1 );
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}
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return( 0 );
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}
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/* Read an ascii 1 bit file.
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*/
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static int
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read_1bit_ascii( FILE *fp, IMAGE *out )
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{
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int x, y;
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PEL *buf;
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if( im_outcheck( out ) || im_setupout( out ) ||
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!(buf = IM_ARRAY( out, IM_IMAGE_SIZEOF_LINE( out ), PEL )) )
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return( -1 );
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for( y = 0; y < out->Ysize; y++ ) {
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for( x = 0; x < out->Xsize * out->Bands; x++ ) {
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int val;
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if( (val = read_uint( fp )) < 0 )
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return( -1 );
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if( val == 1 )
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buf[x] = 0;
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else
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buf[x] = 255;
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}
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if( im_writeline( y, out, buf ) )
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return( -1 );
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}
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return( 0 );
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}
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/* Read a 1 bit binary file.
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*/
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static int
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read_1bit_binary( FILE *fp, IMAGE *out )
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{
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int x, y, i;
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int bits;
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PEL *buf;
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if( im_outcheck( out ) || im_setupout( out ) ||
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!(buf = IM_ARRAY( out, IM_IMAGE_SIZEOF_LINE( out ), PEL )) )
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return( -1 );
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bits = fgetc( fp );
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for( i = 0, y = 0; y < out->Ysize; y++ ) {
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for( x = 0; x < out->Xsize * out->Bands; x++, i++ ) {
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buf[x] = (bits & 128) ? 255 : 0;
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bits <<= 1;
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if( (i & 7) == 7 )
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bits = fgetc( fp );
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}
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if( im_writeline( y, out, buf ) )
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return( -1 );
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}
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return( 0 );
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}
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static int
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parse_ppm( FILE *fp, const char *filename, IMAGE *out )
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{
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int bits;
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int ascii;
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if( read_header( fp, out, &bits, &ascii ) )
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return( -1 );
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/* What sort of read are we doing?
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*/
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if( !ascii && bits >= 8 )
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return( read_mmap( fp, filename, out ) );
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else if( !ascii && bits == 1 )
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return( read_1bit_binary( fp, out ) );
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else if( ascii && bits == 1 )
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return( read_1bit_ascii( fp, out ) );
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else
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return( read_ascii( fp, out ) );
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}
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static int
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ppm2vips_header( const char *filename, IMAGE *out )
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{
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FILE *fp;
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int bits;
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int ascii;
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#ifdef BINARY_OPEN
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if( !(fp = fopen( filename, "rb" )) ) {
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#else /*BINARY_OPEN*/
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if( !(fp = fopen( filename, "r" )) ) {
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#endif /*BINARY_OPEN*/
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im_error( "im_ppm2vips_header",
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_( "unable to open \"%s\"" ), filename );
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return( -1 );
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}
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if( read_header( fp, out, &bits, &ascii ) ) {
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fclose( fp );
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return( -1 );
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}
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fclose( fp );
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return( 0 );
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}
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/* Can this PPM file be read with a mmap?
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*/
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static int
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isppmmmap( const char *filename )
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{
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IMAGE *im;
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FILE *fp;
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int bits;
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int ascii;
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#ifdef BINARY_OPEN
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if( !(fp = fopen( filename, "rb" )) ) {
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#else /*BINARY_OPEN*/
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if( !(fp = fopen( filename, "r" )) ) {
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#endif /*BINARY_OPEN*/
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im_error( "im_ppm2vips_header",
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_( "unable to open \"%s\"" ), filename );
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return( -1 );
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}
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if( !(im = im_open( "temp", "p" )) ) {
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fclose( fp );
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return( 0 );
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}
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if( read_header( fp, im, &bits, &ascii ) ) {
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im_close( im );
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fclose( fp );
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return( 0 );
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}
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im_close( im );
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fclose( fp );
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return( !ascii && bits >= 8 );
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}
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int
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im_ppm2vips( const char *filename, IMAGE *out )
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{
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FILE *fp;
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#ifdef BINARY_OPEN
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if( !(fp = fopen( filename, "rb" )) ) {
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#else /*BINARY_OPEN*/
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if( !(fp = fopen( filename, "r" )) ) {
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#endif /*BINARY_OPEN*/
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im_error( "im_ppm2vips",
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_( "unable to open \"%s\"" ), filename );
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return( -1 );
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}
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if( parse_ppm( fp, filename, out ) ) {
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fclose( fp );
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return( -1 );
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}
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fclose( fp );
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return( 0 );
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}
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static int
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isppm( const char *filename )
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{
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unsigned char buf[2];
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if( im__get_bytes( filename, buf, 2 ) )
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if( buf[0] == 'P' && (buf[1] >= '1' || buf[1] <= '6') )
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return( 1 );
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return( 0 );
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}
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/* ppm flags function.
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*/
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static im_format_flags
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ppm_flags( const char *filename )
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{
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im_format_flags flags;
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flags = 0;
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if( isppmmmap( filename ) )
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flags |= IM_FORMAT_FLAG_PARTIAL;
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return( flags );
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}
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static const char *ppm_suffs[] = { ".ppm", ".pgm", ".pbm", NULL };
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void
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im__ppm_register( void )
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{
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im_format_register(
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"ppm", /* internal name */
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_( "PPM/PBM/PNM" ), /* i18n'd visible name */
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ppm_suffs, /* Allowed suffixes */
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isppm, /* is_a */
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ppm2vips_header, /* Load header only */
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im_ppm2vips, /* Load */
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im_vips2ppm, /* Save */
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ppm_flags /* Flags */
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);
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}
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