libvips/libsrc/format/im_png2vips.c
2009-02-27 16:52:25 +00:00

403 lines
8.5 KiB
C

/* Convert 1 to 4-band 8 or 16-bit VIPS images to/from PNG.
*
* 28/11/03 JC
* - better no-overshoot on tile loop
* 22/2/05
* - read non-interlaced PNG with a line buffer (thanks Michel Brabants)
* 11/1/06
* - read RGBA palette-ized images more robustly (thanks Tom)
* 20/4/06
* - auto convert to sRGB/mono (with optional alpha) for save
* 1/5/06
* - from vips_png.c
* 8/5/06
* - set RGB16/GREY16 if appropriate
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/*
#define DEBUG
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#ifndef HAVE_PNG
#include <vips/vips.h>
int
im_png2vips( const char *name, IMAGE *out )
{
im_error( "im_png2vips", _( "PNG support disabled" ) );
return( -1 );
}
#else /*HAVE_PNG*/
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <vips/vips.h>
#include <vips/internal.h>
#include <png.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
#if PNG_LIBPNG_VER < 10003
#error "PNG library too old."
#endif
static void
user_error_function( png_structp png_ptr, png_const_charp error_msg )
{
im_error( "im_png2vips", _( "PNG error: \"%s\"" ), error_msg );
}
static void
user_warning_function( png_structp png_ptr, png_const_charp warning_msg )
{
im_error( "im_png2vips", _( "PNG warning: \"%s\"" ), warning_msg );
}
/* What we track during a PNG read.
*/
typedef struct {
char *name;
IMAGE *out;
FILE *fp;
png_structp pPng;
png_infop pInfo;
png_bytep *row_pointer;
png_bytep data;
} Read;
static void
read_destroy( Read *read )
{
IM_FREE( read->name );
IM_FREEF( fclose, read->fp );
if( read->pPng )
png_destroy_read_struct( &read->pPng, &read->pInfo, NULL );
IM_FREE( read->row_pointer );
IM_FREE( read->data );
im_free( read );
}
static Read *
read_new( const char *name, IMAGE *out )
{
Read *read;
if( !(read = IM_NEW( NULL, Read )) )
return( NULL );
read->name = im_strdup( NULL, name );
read->out = out;
read->fp = NULL;
read->pPng = NULL;
read->pInfo = NULL;
read->row_pointer = NULL;
read->data = NULL;
#ifdef BINARY_OPEN
if( !(read->fp = fopen( name, "rb" )) ) {
#else /*BINARY_OPEN*/
if( !(read->fp = fopen( name, "r" )) ) {
#endif /*BINARY_OPEN*/
read_destroy( read );
im_error( "im_png2vips", _( "unable to open \"%s\"" ), name );
return( NULL );
}
if( !(read->pPng = png_create_read_struct(
PNG_LIBPNG_VER_STRING, NULL,
user_error_function, user_warning_function )) ) {
read_destroy( read );
return( NULL );
}
/* Catch PNG errors from png_create_info_struct().
*/
if( setjmp( read->pPng->jmpbuf ) ) {
read_destroy( read );
return( NULL );
}
if( !(read->pInfo = png_create_info_struct( read->pPng )) ) {
read_destroy( read );
return( NULL );
}
return( read );
}
/* Yuk! Have to malloc enough space for the whole image. Interlaced PNG
* is not really suitable for large objects ...
*/
static int
png2vips_interlace( Read *read )
{
const int rowbytes = IM_IMAGE_SIZEOF_LINE( read->out );
int y;
if( !(read->row_pointer = IM_ARRAY( NULL,
read->pInfo->height, png_bytep )) )
return( -1 );
if( !(read->data = (png_bytep) im_malloc( NULL,
read->pInfo->height * rowbytes )) )
return( -1 );
for( y = 0; y < (int) read->pInfo->height; y++ )
read->row_pointer[y] = read->data + y * rowbytes;
if( im_outcheck( read->out ) ||
im_setupout( read->out ) ||
setjmp( read->pPng->jmpbuf ) )
return( -1 );
png_read_image( read->pPng, read->row_pointer );
for( y = 0; y < (int) read->pInfo->height; y++ )
if( im_writeline( y, read->out, read->row_pointer[y] ) )
return( -1 );
return( 0 );
}
/* Noninterlaced images can be read without needing enough RAM for the whole
* image.
*/
static int
png2vips_noninterlace( Read *read )
{
const int rowbytes = IM_IMAGE_SIZEOF_LINE( read->out );
int y;
if( !(read->data = (png_bytep) im_malloc( NULL, rowbytes )) )
return( -1 );
if( im_outcheck( read->out ) ||
im_setupout( read->out ) ||
setjmp( read->pPng->jmpbuf ) )
return( -1 );
for( y = 0; y < (int) read->pInfo->height; y++ ) {
png_read_row( read->pPng, read->data, NULL );
if( im_writeline( y, read->out, read->data ) )
return( -1 );
}
return( 0 );
}
/* Read a PNG file (header) into a VIPS (header).
*/
static int
png2vips( Read *read, int header_only )
{
int bands, bpp, type;
if( setjmp( read->pPng->jmpbuf ) )
return( -1 );
png_init_io( read->pPng, read->fp );
png_read_info( read->pPng, read->pInfo );
/* png_get_channels() gives us 1 band for palette images ... so look
* at colour_type for output bands.
*/
switch( read->pInfo->color_type ) {
case PNG_COLOR_TYPE_PALETTE:
bands = 3;
/* Don't know if this is really correct. If there are
* transparent pixels, assume we're going to output RGBA.
*/
if( read->pInfo->num_trans )
bands = 4;
break;
case PNG_COLOR_TYPE_GRAY: bands = 1; break;
case PNG_COLOR_TYPE_GRAY_ALPHA: bands = 2; break;
case PNG_COLOR_TYPE_RGB: bands = 3; break;
case PNG_COLOR_TYPE_RGB_ALPHA: bands = 4; break;
default:
im_error( "im_png2vips", "%s", _( "unsupported colour type" ) );
return( -1 );
}
/* 8 or 16 bit.
*/
bpp = read->pInfo->bit_depth > 8 ? 2 : 1;
if( bpp > 1 ) {
if( bands < 3 )
type = IM_TYPE_GREY16;
else
type = IM_TYPE_RGB16;
}
else {
if( bands < 3 )
type = IM_TYPE_B_W;
else
type = IM_TYPE_sRGB;
}
/* Expand palette images.
*/
if( read->pInfo->color_type == PNG_COLOR_TYPE_PALETTE )
png_set_expand( read->pPng );
/* Expand <8 bit images to full bytes.
*/
if( read->pInfo->bit_depth < 8 )
png_set_packing( read->pPng );
/* If we're an INTEL byte order machine and this is 16bits, we need
* to swap bytes.
*/
if( read->pInfo->bit_depth > 8 && !im_amiMSBfirst() )
png_set_swap( read->pPng );
/* Set VIPS header.
*/
im_initdesc( read->out,
read->pInfo->width, read->pInfo->height, bands,
bpp == 1 ? IM_BBITS_BYTE : IM_BBITS_SHORT,
bpp == 1 ? IM_BANDFMT_UCHAR : IM_BANDFMT_USHORT,
IM_CODING_NONE, type, 1.0, 1.0, 0, 0 );
if( !header_only ) {
if( png_set_interlace_handling( read->pPng ) > 1 ) {
if( png2vips_interlace( read ) )
return( -1 );
}
else {
if( png2vips_noninterlace( read ) )
return( -1 );
}
}
return( 0 );
}
/* Read a PNG file header into a VIPS header.
*/
static int
png2vips_header( const char *name, IMAGE *out )
{
Read *read;
if( !(read = read_new( name, out )) )
return( -1 );
if( png2vips( read, 1 ) ) {
read_destroy( read );
return( -1 );
}
read_destroy( read );
return( 0 );
}
/* Read a PNG file into a VIPS image.
*/
int
im_png2vips( const char *name, IMAGE *out )
{
Read *read;
#ifdef DEBUG
printf( "im_png2vips: reading \"%s\"\n", name );
#endif /*DEBUG*/
if( !(read = read_new( name, out )) )
return( -1 );
if( png2vips( read, 0 ) ) {
read_destroy( read );
return( -1 );
}
read_destroy( read );
return( 0 );
}
static int
ispng( const char *filename )
{
unsigned char buf[8];
return( im__get_bytes( filename, buf, 8 ) &&
!png_sig_cmp( buf, 0, 8 ) );
}
static const char *png_suffs[] = { ".png", NULL };
/* png format adds no new members.
*/
typedef VipsFormat VipsFormatPng;
typedef VipsFormatClass VipsFormatPngClass;
static void
vips_format_png_class_init( VipsFormatPngClass *class )
{
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsFormatClass *format_class = (VipsFormatClass *) class;
object_class->nickname = "png";
object_class->description = _( "PNG" );
format_class->is_a = ispng;
format_class->header = png2vips_header;
format_class->load = im_png2vips;
format_class->save = im_vips2png;
format_class->suffs = png_suffs;
}
static void
vips_format_png_init( VipsFormatPng *object )
{
}
G_DEFINE_TYPE( VipsFormatPng, vips_format_png, VIPS_TYPE_FORMAT );
#endif /*HAVE_PNG*/