path: root/src/jpeg-utils.cpp

/*   Cataract - Static web photo gallery generator
 *   Copyright (C) 2008 Tomas Bzatek <tbzatek@users.sourceforge.net>
 *
 *   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 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <exiv2/image.hpp>
#include <exiv2/exif.hpp>

#include <wand/magick-wand.h>

#include <config.h>

#include "jpeg-utils.h"



/*
 *   get_exif: retrieve EXIF informations from a JPEG image
 */
int
get_exif (const char *filename, TExifData **exif_data)
{
  TExifData *data;

  data = (TExifData*) malloc (sizeof (TExifData));
  memset (data, 0, sizeof (TExifData));
  *exif_data = data;

  try
  {
     Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(filename);
     g_assert (image.get() != 0);
     image->readMetadata();

     Exiv2::ExifData &exifData = image->exifData();
     if (! exifData.empty())  {
       /*  EXIF::Aperture  */
       try {
         float val = exifData["Exif.Photo.FNumber"].toFloat();
         if (val >= 0)
           data->aperture = g_strdup_printf ("f/%.1f", val);
       } catch (...) { }

       /*  EXIF::Camera model  */
       try {
         const char *val = exifData["Exif.Image.Model"].toString().c_str();
         if (val && strlen(val) > 0)
           data->camera_model = strdup (val);
       } catch (...) { }

       /*  EXIF::DateTime  */
       try {
         const char *val = NULL;
         try {
           val = exifData["Exif.Photo.DateTimeOriginal"].toString().c_str();
         } catch (...) { }
         if ((! val) || (strlen(val) == 0))
           try {
             val = exifData["Exif.Image.DateTime"].toString().c_str();
           } catch (...) { }

         if (val && strlen(val) > 0) {
           static struct tm tt;
           static char conv[1024];

           if (sscanf (val, "%d:%d:%d %d:%d:%d", &tt.tm_year, &tt.tm_mon, &tt.tm_mday, &tt.tm_hour, &tt.tm_min, &tt.tm_sec) == 6)
             {
               tt.tm_year -= 1900;
               tt.tm_mon--;
               if (strftime (&conv[0], sizeof(conv), "%c", &tt))
                   data->datetime = strdup (&conv[0]);
             }
         }
       } catch (...) { }

       /*  EXIF::Shutter speed  */
       try {
         float val = exifData["Exif.Photo.ExposureTime"].toFloat();
         if (val > 0) {
           if (val < 0.5)
             data->exposure = g_strdup_printf ("1/%.0f s", 1/val);
           else
             data->exposure = g_strdup_printf ("%.1f s", val);
         }
       } catch (...) { }

       /*  EXIF::Flash  */
       try {
         long int val = exifData["Exif.Photo.Flash"].toLong();
         if ((val > 0) && ((val & 1) == 1))
           data->flash = strdup ((char *) "Flash fired");
         else
           data->flash = strdup ((char *) "--");
       } catch (...) { }

       /*  EXIF::Focal length  */
       try {
         float val = exifData["Exif.Photo.FocalLength"].toFloat();
         if (val >= 0)
           data->focal_length = g_strdup_printf ("%.0f mm", val);
       } catch (...) { }

       /*  EXIF::ISO  */
       try {
         long int val = exifData["Exif.Photo.ISOSpeedRatings"].toLong();
         if (val > 0)
           data->iso = g_strdup_printf ("%ld", val);
       } catch (...) { }

       /*  EXIF::Software  */
       try {
         data->exif_software = strdup (exifData["Exif.Image.Software"].toString().c_str());
       } catch (...) { }

       /*  EXIF::Image description  */
       try {
         data->exif_imgdesc = strdup (exifData["Exif.Image.ImageDescription"].toString().c_str());
       } catch (...) { }

       /*  EXIF::Artist  */
       try {
         data->exif_artist = strdup (exifData["Exif.Image.Artist"].toString().c_str());
       } catch (...) { }

       /*  EXIF::Copyright  */
       try {
         data->exif_copyright = strdup (exifData["Exif.Image.Copyright"].toString().c_str());
       } catch (...) { }

       /*  EXIF::User comment  */
       try {
         data->exif_usercomment = strdup (exifData["Exif.Photo.UserComment"].toString().c_str());
       } catch (...) { }
     }

     Exiv2::IptcData &iptcData = image->iptcData();
     if (! iptcData.empty()) {
       /*  IPTC::Object name  */
       try {
         data->iptc_objectname = strdup (iptcData["Iptc.Application2.ObjectName"].toString().c_str());
       } catch (...) { }

       /*  IPTC::Copyright  */
       try {
         data->iptc_copyright = strdup (iptcData["Iptc.Application2.Copyright"].toString().c_str());
       } catch (...) { }

       /*  IPTC::Credit  */
       try {
         data->iptc_credit = strdup (iptcData["Iptc.Application2.Credit"].toString().c_str());
       } catch (...) { }

       /*  IPTC::Caption  */
       try {
         data->iptc_caption = strdup (iptcData["Iptc.Application2.Caption"].toString().c_str());
       } catch (...) { }

       /*  IPTC::Author  */
       try {
         data->iptc_author = strdup (iptcData["Iptc.Application2.Byline"].toString().c_str());
       } catch (...) { }
     }

     /*  JPEG::Comment  */
     try {
       data->jpeg_comment = strdup (image->comment().c_str());
     } catch (...) { }
  }
  catch (Exiv2::AnyError& e)
  {
    fprintf (stderr, "get_exif: Caught Exiv2 exception: '%s'\n", e.what());
    return -1;
  }

#ifdef __DEBUG_ALL__
    printf("EXIF_TAG_DATE_TIME = '%s'\n", data->datetime);
    printf("EXIF_TAG_MODEL = '%s'\n", data->camera_model);
    printf("EXIF_TAG_ISO_SPEED_RATINGS = '%s'\n", data->iso);
    printf("EXIF_TAG_FOCAL_LENGTH = '%s'\n", data->focal_length);
    printf("EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM = '%s'\n", data->focal_length_35mm);
    printf("EXIF_TAG_FNUMBER = '%s'\n", data->aperture);
    printf("EXIF_TAG_EXPOSURE_TIME = '%s'\n", data->exposure);
    printf("EXIF_TAG_FLASH = '%s'\n", data->flash);
    printf("Exif.Image.Software = '%s'\n", data->exif_software);
    printf("Exif.Image.ImageDescription = '%s'\n", data->exif_imgdesc);
    printf("Exif.Image.Artist = '%s'\n", data->exif_artist);
    printf("Exif.Image.Copyright = '%s'\n", data->exif_copyright);
    printf("Exif.Photo.UserComment = '%s'\n", data->exif_usercomment);
    printf("Iptc.Application2.ObjectName = '%s'\n", data->iptc_objectname);
    printf("Iptc.Application2.Copyright = '%s'\n", data->iptc_copyright);
    printf("Iptc.Application2.Credit = '%s'\n", data->iptc_credit);
    printf("Iptc.Application2.Caption = '%s'\n", data->iptc_caption);
    printf("Iptc.Application2.Byline = '%s'\n", data->iptc_author);
    printf("JPEG comment = '%s'\n", data->jpeg_comment);
#endif

  return 0;
}

/*
 *   free_exif_struct: free allocated structure
 */
void
free_exif_data (TExifData *data)
{
  if (data) {
    if (data->aperture)
    	free (data->aperture);
    if (data->camera_model)
    	free (data->camera_model);
    if (data->datetime)
    	free (data->datetime);
    if (data->exposure)
    	free (data->exposure);
    if (data->flash)
    	free (data->flash);
    if (data->focal_length)
    	free (data->focal_length);
    if (data->focal_length_35mm)
    	free (data->focal_length_35mm);
    if (data->iso)
    	free (data->iso);

    if (data->exif_software)
        free (data->exif_software);
    if (data->exif_imgdesc)
        free (data->exif_imgdesc);
    if (data->exif_artist)
        free (data->exif_artist);
    if (data->exif_copyright)
        free (data->exif_copyright);
    if (data->exif_usercomment)
        free (data->exif_usercomment);

    if (data->iptc_objectname)
        free (data->iptc_objectname);
    if (data->iptc_copyright)
        free (data->iptc_copyright);
    if (data->iptc_credit)
        free (data->iptc_credit);
    if (data->iptc_caption)
        free (data->iptc_caption);
    if (data->iptc_author)
        free (data->iptc_author);

    if (data->jpeg_comment)
        free (data->jpeg_comment);

    free (data);
    data = NULL;
  }
}


/*
 *   resize_image: resize image pointed by src and save result to dst
 */
gboolean
resize_image (const char *src, const char *dst,
	          int size_x, int size_y,
	          int quality,
                  gboolean thumbnail)
{
  #define ThrowWandException(wand) \
  { \
    char *description; \
    ExceptionType severity; \
   \
    description = MagickGetException (wand, &severity); \
    (void) fprintf (stderr, "Error converting image: %s %s %ld %s\n", GetMagickModule(), description); \
    description = (char*) MagickRelinquishMemory (description); \
    return FALSE; \
  }

  MagickBooleanType status;
  MagickWand *magick_wand;

  /*  Read an image.  */
  MagickWandGenesis();
  magick_wand = NewMagickWand();
  status = MagickReadImage (magick_wand, src);
  if (status == MagickFalse)
	  ThrowWandException (magick_wand);
  if (thumbnail)
    MagickThumbnailImage (magick_wand, size_x, size_y);
  else
    MagickResizeImage (magick_wand, size_x, size_y, LanczosFilter, 1.0);
  MagickSetImageCompressionQuality (magick_wand, quality);

  /*  Write the image and destroy it.  */
  status = MagickWriteImage (magick_wand, dst);
  if (status == MagickFalse)
	  ThrowWandException (magick_wand);
  magick_wand = DestroyMagickWand (magick_wand);
  MagickWandTerminus();

  return TRUE;
}


/*
 *   get_image_sizes: retrieve image dimensions
 */
void
get_image_sizes (const char *img,
                 unsigned long *width, unsigned long *height)
{
  #define xThrowWandException(wand) \
  { \
    char *description; \
    ExceptionType severity; \
   \
    description = MagickGetException (wand, &severity); \
    (void) fprintf (stderr, "Error reading image info: %s %s %ld %s\n", GetMagickModule(), description); \
    description = (char*) MagickRelinquishMemory(description); \
    return; \
  }

  MagickBooleanType status;
  MagickWand *magick_wand;

  *width = -1;
  *height = -1;

  /*  Read an image.  */
  MagickWandGenesis();
  magick_wand = NewMagickWand();
  status = MagickPingImage (magick_wand, img);
  if (status == MagickFalse)
	  xThrowWandException (magick_wand);
  *width = MagickGetImageWidth (magick_wand);
  *height = MagickGetImageHeight (magick_wand);

  magick_wand = DestroyMagickWand (magick_wand);
  MagickWandTerminus();
}


/*
 *   calculate_sizes: calculate maximal image sizes within specified limits keeping aspect ratio
 */
void
calculate_sizes (const unsigned long max_width, const unsigned long max_height,
                 unsigned long *width, unsigned long *height)
{
  if ((max_width > *width) && (max_height > *height))
	  return;

  double max_ratio = (double) max_width / (double) max_height;
  double real_ratio = (double) *width / (double) *height;

  if ((*width > *height) && (max_ratio <= real_ratio))
    {
      *height = (unsigned long) (max_width / real_ratio);
      *width = max_width;
    }
  else
    {
      *width = (unsigned long) (max_height * real_ratio);
      *height = max_height;
    }
}


/*
 *   modify_exif: - strip thumbnail stored in EXIF table
 *                - add copyright to Exif::Image::Copyright and Iptc::Application2::Copyright
 */
void
modify_exif (const char *filename, gboolean strip_thumbnail, const char *add_copyright)
{
  bool was_modified = false;

  if ((! strip_thumbnail) && (add_copyright == NULL))
    return;

  try
  {
     Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(filename);
     g_assert (image.get() != 0);

     image->readMetadata();
     Exiv2::ExifData &exifData = image->exifData();
     if (add_copyright) {
       exifData["Exif.Image.Copyright"] = add_copyright;
       image->iptcData()["Iptc.Application2.Copyright"] = add_copyright;
       was_modified = true;
     }

     if (strip_thumbnail && (! exifData.empty()))  {
#ifdef HAVE_EXIFTHUMB
       Exiv2::ExifThumb exifThumb(image->exifData());
       std::string thumbExt = exifThumb.extension();
#else
       std::string thumbExt = exifData.thumbnailExtension();
#endif

       if (! thumbExt.empty()) {
#ifdef HAVE_EXIFTHUMB
         exifThumb.erase();
#else
         exifData.eraseThumbnail();
#endif
         was_modified = true;
       }
     }

     if (was_modified)
       image->writeMetadata();
  }
  catch (Exiv2::AnyError& e)
  {
    fprintf (stderr, "modify_exif: Caught Exiv2 exception: '%s'\n", e.what());
  }
}