gimp/plug-ins/jpeg/jpeg-load.c

942 lines
26 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU 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.
*/
#include "config.h"
#include <string.h>
#include <errno.h>
#include <setjmp.h>
#include <glib/gstdio.h>
#include <jpeglib.h>
#include <jerror.h>
#ifdef HAVE_EXIF
#include <libexif/exif-data.h>
#endif /* HAVE_EXIF */
#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>
#include "libgimp/stdplugins-intl.h"
#include "jpeg.h"
#include "jpeg-icc.h"
#include "jpeg-load.h"
gint32 volatile image_ID_global;
GimpDrawable *drawable_global;
gint32 layer_ID_global;
gint32
load_image (const gchar *filename,
GimpRunMode runmode,
gboolean preview)
{
GimpPixelRgn pixel_rgn;
GimpDrawable *drawable;
gint32 volatile image_ID;
gint32 layer_ID;
struct jpeg_decompress_struct cinfo;
struct my_error_mgr jerr;
FILE *infile;
guchar *buf;
guchar * volatile padded_buf = NULL;
guchar **rowbuf;
guchar *profile;
guint profile_size;
gint image_type;
gint layer_type;
gint tile_height;
gint scanlines;
gint i, start, end;
GString *local_image_comments = NULL;
GimpParasite * volatile comment_parasite = NULL;
jpeg_saved_marker_ptr marker;
/* We set up the normal JPEG error routines. */
cinfo.err = jpeg_std_error (&jerr.pub);
jerr.pub.error_exit = my_error_exit;
/* flag warnings, so we try to ignore corrupt EXIF data */
if (!preview)
{
cinfo.client_data = GINT_TO_POINTER (FALSE);
jerr.pub.emit_message = my_emit_message;
jerr.pub.output_message = my_output_message;
}
if ((infile = g_fopen (filename, "rb")) == NULL)
{
g_message (_("Could not open '%s' for reading: %s"),
gimp_filename_to_utf8 (filename), g_strerror (errno));
gimp_quit ();
}
if (!preview)
gimp_progress_init_printf (_("Opening '%s'"),
gimp_filename_to_utf8 (filename));
image_ID = -1;
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp (jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object, close the input file, and return.
*/
jpeg_destroy_decompress (&cinfo);
if (infile)
fclose (infile);
if (image_ID != -1 && !preview)
gimp_image_delete (image_ID);
if (preview)
destroy_preview();
gimp_quit ();
}
/* Now we can initialize the JPEG decompression object. */
jpeg_create_decompress (&cinfo);
/* Step 2: specify data source (eg, a file) */
jpeg_stdio_src (&cinfo, infile);
if (! preview)
{
/* - step 2.1: tell the lib to save the comments */
jpeg_save_markers (&cinfo, JPEG_COM, 0xffff);
/* - step 2.2: tell the lib to save APP1 markers
* (may contain EXIF or XMP)
*/
jpeg_save_markers (&cinfo, JPEG_APP0 + 1, 0xffff);
/* - step 2.3: tell the lib to keep any APP2 data it may find */
jpeg_icc_setup_read_profile (&cinfo);
}
/* Step 3: read file parameters with jpeg_read_header() */
(void) jpeg_read_header (&cinfo, TRUE);
/* We can ignore the return value from jpeg_read_header since
* (a) suspension is not possible with the stdio data source, and
* (b) we passed TRUE to reject a tables-only JPEG file as an error.
* See libjpeg.doc for more info.
*/
/* Step 4: set parameters for decompression */
/* In this example, we don't need to change any of the defaults set by
* jpeg_read_header(), so we do nothing here.
*/
/* Step 5: Start decompressor */
jpeg_start_decompress (&cinfo);
/* We may need to do some setup of our own at this point before reading
* the data. After jpeg_start_decompress() we have the correct scaled
* output image dimensions available, as well as the output colormap
* if we asked for color quantization.
* In this example, we need to make an output work buffer of the right size.
*/
/* temporary buffer */
tile_height = gimp_tile_height ();
buf = g_new (guchar,
tile_height * cinfo.output_width * cinfo.output_components);
rowbuf = g_new (guchar *, tile_height);
for (i = 0; i < tile_height; i++)
rowbuf[i] = buf + cinfo.output_width * cinfo.output_components * i;
/* Create a new image of the proper size and associate the filename with it.
Preview layers, not being on the bottom of a layer stack, MUST HAVE
AN ALPHA CHANNEL!
*/
switch (cinfo.output_components)
{
case 1:
image_type = GIMP_GRAY;
layer_type = preview ? GIMP_GRAYA_IMAGE : GIMP_GRAY_IMAGE;
break;
case 3:
image_type = GIMP_RGB;
layer_type = preview ? GIMP_RGBA_IMAGE : GIMP_RGB_IMAGE;
break;
case 4:
if (cinfo.out_color_space == JCS_CMYK)
{
image_type = GIMP_RGB;
layer_type = GIMP_RGB_IMAGE;
break;
}
/*fallthrough*/
default:
g_message ("Don't know how to load JPEG images "
"with %d color channels, using colorspace %d (%d).",
cinfo.output_components, cinfo.out_color_space,
cinfo.jpeg_color_space);
gimp_quit ();
break;
}
if (preview)
padded_buf = g_new (guchar, tile_height * cinfo.output_width *
(cinfo.output_components + 1));
else if (cinfo.out_color_space == JCS_CMYK)
padded_buf = g_new (guchar, tile_height * cinfo.output_width * 3);
else
padded_buf = NULL;
if (preview)
{
image_ID = image_ID_global;
}
else
{
image_ID = gimp_image_new (cinfo.output_width, cinfo.output_height,
image_type);
gimp_image_set_filename (image_ID, filename);
}
if (preview)
{
layer_ID_global = layer_ID =
gimp_layer_new (image_ID, _("JPEG preview"),
cinfo.output_width,
cinfo.output_height,
layer_type, 100, GIMP_NORMAL_MODE);
}
else
{
layer_ID = gimp_layer_new (image_ID, _("Background"),
cinfo.output_width,
cinfo.output_height,
layer_type, 100, GIMP_NORMAL_MODE);
}
drawable_global = drawable = gimp_drawable_get (layer_ID);
gimp_pixel_rgn_init (&pixel_rgn, drawable, 0, 0,
drawable->width, drawable->height, TRUE, FALSE);
/* Step 5.1: if the file had resolution information, set it on the image */
if (!preview && cinfo.saw_JFIF_marker)
{
gdouble xresolution;
gdouble yresolution;
gdouble asymmetry;
xresolution = cinfo.X_density;
yresolution = cinfo.Y_density;
switch (cinfo.density_unit)
{
case 0: /* unknown -> set the aspect ratio but use the default
* image resolution
*/
if (cinfo.Y_density != 0)
asymmetry = xresolution / yresolution;
else
asymmetry = 1.0;
gimp_image_get_resolution (image_ID, &xresolution, &yresolution);
xresolution *= asymmetry;
break;
case 1: /* dots per inch */
break;
case 2: /* dots per cm */
xresolution *= 2.54;
yresolution *= 2.54;
gimp_image_set_unit (image_ID, GIMP_UNIT_MM);
break;
default:
g_message ("Unknown density unit %d, assuming dots per inch.",
cinfo.density_unit);
break;
}
gimp_image_set_resolution (image_ID, xresolution, yresolution);
}
/* Step 5.2: check for metadata (comments, markers containing EXIF or XMP) */
for (marker = cinfo.marker_list; marker; marker = marker->next)
{
const gchar *data = (const gchar *) marker->data;
gsize len = marker->data_length;
if (marker->marker == JPEG_COM)
{
g_print ("jpeg-load: found image comment (%d bytes)\n",
marker->data_length);
if (!local_image_comments)
{
local_image_comments = g_string_new_len (data, len);
}
else
{
g_string_append_c (local_image_comments, '\n');
g_string_append_len (local_image_comments, data, len);
}
}
else if ((marker->marker == JPEG_APP0 + 1)
&& (len > 13)
&& ! strcmp (JPEG_APP_HEADER_EXIF, data))
{
/* FIXME: handle EXIF here once we don't use libexif anymore */
g_print ("jpeg-load: found EXIF block (%d bytes)\n",
(gint) (len - sizeof (JPEG_APP_HEADER_EXIF)));
/* Note: maybe split the loop to ensure that the EXIF block is */
/* always parsed before any XMP packet */
}
else if ((marker->marker == JPEG_APP0 + 1)
&& (len > 37)
&& ! strcmp (JPEG_APP_HEADER_XMP, data))
{
GimpParam *return_vals;
gint nreturn_vals;
gchar *xmp_packet;
g_print ("jpeg-load: found XMP packet (%d bytes)\n",
(gint) (len - sizeof (JPEG_APP_HEADER_XMP)));
xmp_packet = g_strndup (data + sizeof (JPEG_APP_HEADER_XMP),
len - sizeof (JPEG_APP_HEADER_XMP));
/* FIXME: running this through the PDB is not very efficient */
return_vals = gimp_run_procedure ("plug-in-metadata-decode-xmp",
&nreturn_vals,
GIMP_PDB_IMAGE, image_ID,
GIMP_PDB_STRING, xmp_packet,
GIMP_PDB_END);
if (return_vals[0].data.d_status != GIMP_PDB_SUCCESS)
{
g_warning ("JPEG - unable to decode XMP metadata packet");
}
gimp_destroy_params (return_vals, nreturn_vals);
g_free (xmp_packet);
}
}
/* Step 5.3: check for an embedded ICC profile */
if (!preview && jpeg_icc_read_profile (&cinfo, &profile, &profile_size))
{
GimpParasite *parasite = gimp_parasite_new ("icc-profile",
0, profile_size, profile);
gimp_image_parasite_attach (image_ID, parasite);
gimp_parasite_free (parasite);
g_free (profile);
}
if (!preview)
{
/* if we had any comments then make a parasite for them */
if (local_image_comments && local_image_comments->len)
{
gchar *comment = local_image_comments->str;
g_string_free (local_image_comments, FALSE);
local_image_comments = NULL;
if (g_utf8_validate (comment, -1, NULL))
comment_parasite = gimp_parasite_new ("gimp-comment",
GIMP_PARASITE_PERSISTENT,
strlen (comment) + 1,
comment);
g_free (comment);
}
/* Do not attach the "jpeg-save-options" parasite to the image
* because this conflicts with the global defaults (bug #75398).
*/
}
/* Step 6: while (scan lines remain to be read) */
/* jpeg_read_scanlines(...); */
/* Here we use the library's state variable cinfo.output_scanline as the
* loop counter, so that we don't have to keep track ourselves.
*/
while (cinfo.output_scanline < cinfo.output_height)
{
start = cinfo.output_scanline;
end = cinfo.output_scanline + tile_height;
end = MIN (end, cinfo.output_height);
scanlines = end - start;
for (i = 0; i < scanlines; i++)
jpeg_read_scanlines (&cinfo, (JSAMPARRAY) &rowbuf[i], 1);
if (preview) /* Add a dummy alpha channel -- convert buf to padded_buf */
{
guchar *dest = padded_buf;
guchar *src = buf;
gint num = drawable->width * scanlines;
switch (cinfo.output_components)
{
case 1:
for (i = 0; i < num; i++)
{
*(dest++) = *(src++);
*(dest++) = 255;
}
break;
case 3:
for (i = 0; i < num; i++)
{
*(dest++) = *(src++);
*(dest++) = *(src++);
*(dest++) = *(src++);
*(dest++) = 255;
}
break;
default:
g_warning ("JPEG - shouldn't have gotten here.\n"
"Report to http://bugzilla.gnome.org/");
break;
}
}
else if (cinfo.out_color_space == JCS_CMYK) /* buf-> RGB in padded_buf */
{
guchar *dest = padded_buf;
guchar *src = buf;
gint num = drawable->width * scanlines;
for (i = 0; i < num; i++)
{
guint r_c, g_m, b_y, a_k;
r_c = *(src++);
g_m = *(src++);
b_y = *(src++);
a_k = *(src++);
*(dest++) = (r_c * a_k) / 255;
*(dest++) = (g_m * a_k) / 255;
*(dest++) = (b_y * a_k) / 255;
}
}
gimp_pixel_rgn_set_rect (&pixel_rgn, padded_buf ? padded_buf : buf,
0, start, drawable->width, scanlines);
if (! preview)
gimp_progress_update ((gdouble) cinfo.output_scanline /
(gdouble) cinfo.output_height);
}
/* Step 7: Finish decompression */
jpeg_finish_decompress (&cinfo);
/* We can ignore the return value since suspension is not possible
* with the stdio data source.
*/
/* Step 8: Release JPEG decompression object */
/* This is an important step since it will release a good deal of memory. */
jpeg_destroy_decompress (&cinfo);
/* free up the temporary buffers */
g_free (rowbuf);
g_free (buf);
g_free (padded_buf);
/* After finish_decompress, we can close the input file.
* Here we postpone it until after no more JPEG errors are possible,
* so as to simplify the setjmp error logic above. (Actually, I don't
* think that jpeg_destroy can do an error exit, but why assume anything...)
*/
fclose (infile);
/* At this point you may want to check to see whether any corrupt-data
* warnings occurred (test whether jerr.num_warnings is nonzero).
*/
/* Detach from the drawable and add it to the image.
*/
if (!preview)
gimp_drawable_detach (drawable);
gimp_image_add_layer (image_ID, layer_ID, 0);
/* pw - Last of all, attach the parasites (couldn't do it earlier -
there was no image. */
if (!preview)
{
if (comment_parasite)
{
gimp_image_parasite_attach (image_ID, comment_parasite);
gimp_parasite_free (comment_parasite);
comment_parasite = NULL;
}
#ifdef HAVE_EXIF
if (! GPOINTER_TO_INT (cinfo.client_data))
jpeg_apply_exif_data_to_image (filename, image_ID);
#endif
}
return image_ID;
}
#ifdef HAVE_EXIF
typedef struct
{
struct jpeg_source_mgr pub; /* public fields */
guchar *buffer;
gint size;
JOCTET terminal[2];
} my_source_mgr;
typedef my_source_mgr * my_src_ptr;
static void
init_source (j_decompress_ptr cinfo)
{
}
static boolean
fill_input_buffer (j_decompress_ptr cinfo)
{
my_src_ptr src = (my_src_ptr) cinfo->src;
/* Since we have given all we have got already
* we simply fake an end of file
*/
src->pub.next_input_byte = src->terminal;
src->pub.bytes_in_buffer = 2;
src->terminal[0] = (JOCTET) 0xFF;
src->terminal[1] = (JOCTET) JPEG_EOI;
return TRUE;
}
static void
skip_input_data (j_decompress_ptr cinfo,
long num_bytes)
{
my_src_ptr src = (my_src_ptr) cinfo->src;
src->pub.next_input_byte = src->pub.next_input_byte + num_bytes;
}
static void
term_source (j_decompress_ptr cinfo)
{
}
gint32
load_thumbnail_image (const gchar *filename,
gint *width,
gint *height)
{
gint32 volatile image_ID;
ExifData *exif_data;
GimpPixelRgn pixel_rgn;
GimpDrawable *drawable;
gint32 layer_ID;
struct jpeg_decompress_struct cinfo;
struct my_error_mgr jerr;
guchar *buf;
guchar * volatile padded_buf = NULL;
guchar **rowbuf;
gint image_type;
gint layer_type;
gint tile_height;
gint scanlines;
gint i, start, end;
my_src_ptr src;
FILE *infile;
image_ID = -1;
exif_data = jpeg_exif_data_new_from_file (filename, NULL);
if (! ((exif_data) && (exif_data->data) && (exif_data->size > 0)))
return -1;
cinfo.err = jpeg_std_error (&jerr.pub);
jerr.pub.error_exit = my_error_exit;
cinfo.client_data = GINT_TO_POINTER (FALSE);
jerr.pub.emit_message = my_emit_message;
jerr.pub.output_message = my_output_message;
gimp_progress_init_printf (_("Opening thumbnail for '%s'"),
gimp_filename_to_utf8 (filename));
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp (jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error. We
* need to clean up the JPEG object, close the input file,
* and return.
*/
jpeg_destroy_decompress (&cinfo);
if (image_ID != -1)
gimp_image_delete (image_ID);
if (exif_data)
{
exif_data_unref (exif_data);
exif_data = NULL;
}
return -1;
}
/* Now we can initialize the JPEG decompression object. */
jpeg_create_decompress (&cinfo);
/* Step 2: specify data source (eg, a file) */
if (cinfo.src == NULL)
cinfo.src = (struct jpeg_source_mgr *)(*cinfo.mem->alloc_small)
((j_common_ptr) &cinfo, JPOOL_PERMANENT,
sizeof (my_source_mgr));
src = (my_src_ptr) cinfo.src;
src->pub.init_source = init_source;
src->pub.fill_input_buffer = fill_input_buffer;
src->pub.skip_input_data = skip_input_data;
src->pub.resync_to_restart = jpeg_resync_to_restart;
src->pub.term_source = term_source;
src->pub.bytes_in_buffer = exif_data->size;
src->pub.next_input_byte = exif_data->data;
src->buffer = exif_data->data;
src->size = exif_data->size;
/* Step 3: read file parameters with jpeg_read_header() */
jpeg_read_header (&cinfo, TRUE);
/* Step 4: set parameters for decompression */
/* In this example, we don't need to change any of the defaults set by
* jpeg_read_header(), so we do nothing here.
*/
/* Step 5: Start decompressor */
jpeg_start_decompress (&cinfo);
/* We may need to do some setup of our own at this point before
* reading the data. After jpeg_start_decompress() we have the
* correct scaled output image dimensions available, as well as
* the output colormap if we asked for color quantization. In
* this example, we need to make an output work buffer of the
* right size.
*/
/* temporary buffer */
tile_height = gimp_tile_height ();
buf = g_new (guchar,
tile_height * cinfo.output_width * cinfo.output_components);
rowbuf = g_new (guchar *, tile_height);
for (i = 0; i < tile_height; i++)
rowbuf[i] = buf + cinfo.output_width * cinfo.output_components * i;
/* Create a new image of the proper size and associate the
* filename with it.
*
* Preview layers, not being on the bottom of a layer stack,
* MUST HAVE AN ALPHA CHANNEL!
*/
switch (cinfo.output_components)
{
case 1:
image_type = GIMP_GRAY;
layer_type = GIMP_GRAY_IMAGE;
break;
case 3:
image_type = GIMP_RGB;
layer_type = GIMP_RGB_IMAGE;
break;
case 4:
if (cinfo.out_color_space == JCS_CMYK)
{
image_type = GIMP_RGB;
layer_type = GIMP_RGB_IMAGE;
break;
}
/*fallthrough*/
default:
g_message ("Don't know how to load JPEG images "
"with %d color channels, using colorspace %d (%d).",
cinfo.output_components, cinfo.out_color_space,
cinfo.jpeg_color_space);
if (exif_data)
{
exif_data_unref (exif_data);
exif_data = NULL;
}
return -1;
break;
}
if (cinfo.out_color_space == JCS_CMYK)
padded_buf = g_new (guchar, tile_height * cinfo.output_width * 3);
else
padded_buf = NULL;
image_ID = gimp_image_new (cinfo.output_width, cinfo.output_height,
image_type);
gimp_image_set_filename (image_ID, filename);
layer_ID = gimp_layer_new (image_ID, _("Background"),
cinfo.output_width,
cinfo.output_height,
layer_type, 100, GIMP_NORMAL_MODE);
drawable_global = drawable = gimp_drawable_get (layer_ID);
gimp_pixel_rgn_init (&pixel_rgn, drawable, 0, 0,
drawable->width, drawable->height, TRUE, FALSE);
/* Step 5.1: if the file had resolution information, set it on the image */
if (cinfo.saw_JFIF_marker)
{
gdouble xresolution;
gdouble yresolution;
gdouble asymmetry;
xresolution = cinfo.X_density;
yresolution = cinfo.Y_density;
switch (cinfo.density_unit)
{
case 0: /* unknown -> set the aspect ratio but use the default
* image resolution
*/
if (cinfo.Y_density != 0)
asymmetry = xresolution / yresolution;
else
asymmetry = 1.0;
gimp_image_get_resolution (image_ID, &xresolution, &yresolution);
xresolution *= asymmetry;
break;
case 1: /* dots per inch */
break;
case 2: /* dots per cm */
xresolution *= 2.54;
yresolution *= 2.54;
gimp_image_set_unit (image_ID, GIMP_UNIT_MM);
break;
default:
g_message ("Unknown density unit %d, assuming dots per inch.",
cinfo.density_unit);
break;
}
gimp_image_set_resolution (image_ID, xresolution, yresolution);
}
/* Step 6: while (scan lines remain to be read) */
/* jpeg_read_scanlines(...); */
/* Here we use the library's state variable cinfo.output_scanline as the
* loop counter, so that we don't have to keep track ourselves.
*/
while (cinfo.output_scanline < cinfo.output_height)
{
start = cinfo.output_scanline;
end = cinfo.output_scanline + tile_height;
end = MIN (end, cinfo.output_height);
scanlines = end - start;
for (i = 0; i < scanlines; i++)
jpeg_read_scanlines (&cinfo, (JSAMPARRAY) &rowbuf[i], 1);
if (cinfo.out_color_space == JCS_CMYK) /* buf-> RGB in padded_buf */
{
guchar *dest = padded_buf;
guchar *src = buf;
gint num = drawable->width * scanlines;
for (i = 0; i < num; i++)
{
guint r_c, g_m, b_y, a_k;
r_c = *(src++);
g_m = *(src++);
b_y = *(src++);
a_k = *(src++);
*(dest++) = (r_c * a_k) / 255;
*(dest++) = (g_m * a_k) / 255;
*(dest++) = (b_y * a_k) / 255;
}
}
gimp_pixel_rgn_set_rect (&pixel_rgn, padded_buf ? padded_buf : buf,
0, start, drawable->width, scanlines);
gimp_progress_update ((gdouble) cinfo.output_scanline /
(gdouble) cinfo.output_height);
}
/* Step 7: Finish decompression */
jpeg_finish_decompress (&cinfo);
/* We can ignore the return value since suspension is not possible
* with the stdio data source.
*/
/* Step 8: Release JPEG decompression object */
/* This is an important step since it will release a good deal
* of memory.
*/
jpeg_destroy_decompress (&cinfo);
/* free up the temporary buffers */
g_free (rowbuf);
g_free (buf);
g_free (padded_buf);
/* At this point you may want to check to see whether any
* corrupt-data warnings occurred (test whether
* jerr.num_warnings is nonzero).
*/
gimp_image_add_layer (image_ID, layer_ID, 0);
/* NOW to get the dimensions of the actual image to return the
* calling app
*/
cinfo.err = jpeg_std_error (&jerr.pub);
jerr.pub.error_exit = my_error_exit;
cinfo.client_data = GINT_TO_POINTER (FALSE);
jerr.pub.emit_message = my_emit_message;
jerr.pub.output_message = my_output_message;
if ((infile = g_fopen (filename, "rb")) == NULL)
{
g_message (_("Could not open '%s' for reading: %s"),
gimp_filename_to_utf8 (filename), g_strerror (errno));
if (exif_data)
{
exif_data_unref (exif_data);
exif_data = NULL;
}
return -1;
}
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp (jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error. We
* need to clean up the JPEG object, close the input file,
* and return.
*/
jpeg_destroy_decompress (&cinfo);
if (image_ID != -1)
gimp_image_delete (image_ID);
if (exif_data)
{
exif_data_unref (exif_data);
exif_data = NULL;
}
return -1;
}
/* Now we can initialize the JPEG decompression object. */
jpeg_create_decompress (&cinfo);
/* Step 2: specify data source (eg, a file) */
jpeg_stdio_src (&cinfo, infile);
/* Step 3: read file parameters with jpeg_read_header() */
jpeg_read_header (&cinfo, TRUE);
jpeg_start_decompress (&cinfo);
*width = cinfo.output_width;
*height = cinfo.output_height;
/* Step 4: Release JPEG decompression object */
/* This is an important step since it will release a good deal
* of memory.
*/
jpeg_destroy_decompress (&cinfo);
fclose (infile);
if (exif_data)
{
exif_data_unref (exif_data);
exif_data = NULL;
}
return image_ID;
}
#endif /* HAVE_EXIF */