Add support for squared thumbnails

Disabled by default, only very simple center crop implemented.
The SQUARED_SIMPLE_SHAVE_AMOUNT constant may be slightly adjusted
according to future experience. It's a really dumb algorithm which
may not be suitable for every picture.

Looking for a fast and smart algorithm to determine image weight center
and radius, i.e. focus on object of interest. The OpenCV's face recognition
features are worth to test and consider, though I fear the speed issues.

5 files changed, 61 insertions, 9 deletions

diff --git a/src/generators.c b/src/generators.c
index f0ba940..cf32819 100644
--- a/src/generators.c
+++ b/src/generators.c
@@ -171,11 +171,17 @@ generate_image (TGallerySetup *setup,
       *thumb_portrait = (thumb_w / thumb_h) < 1;
 
       if ((thumb_w > 0) && (thumb_h > 0)) {
+        /*  Squared thumbnails  */
+        if (setup->squared_thumbnail_type != THUMBNAIL_SQUARE_TYPE_NONE) {
+          thumb_w = setup->thumbnail_square_size;
+          thumb_h = setup->thumbnail_square_size;
+        } else
+        /*  Portrait / Landscape thumbnails  */
         if (! *thumb_portrait)
           calculate_sizes (setup->thumbnail_landscape_width, setup->thumbnail_landscape_height, &thumb_w, &thumb_h);
         else
           calculate_sizes (setup->thumbnail_portrait_width, setup->thumbnail_portrait_height, &thumb_w, &thumb_h);
-        if (! resize_image (thumb_src_full, thumb_dst, thumb_w, thumb_h, setup->thumbnail_quality, TRUE))
+        if (! resize_image (thumb_src_full, thumb_dst, thumb_w, thumb_h, setup->thumbnail_quality, TRUE, setup->squared_thumbnail_type))
           log_error ("generate_image: error resizing thumbnail %s\n", thumb_src_full);
       } else
         log_error ("generate_image: thumbnail %s sizes are %lux%lu\n", thumb_src_full, thumb_w, thumb_h);
@@ -208,7 +214,7 @@ generate_image (TGallerySetup *setup,
           }
 
           g_assert (img_src_full != NULL);
-          if (! resize_image (img_src_full, big_dst, new_w, new_h, bigq, FALSE))
+          if (! resize_image (img_src_full, big_dst, new_w, new_h, bigq, FALSE, 0))
             log_error ("generate_image: error resizing big image %s\n", img_src_full);
         }
         else
@@ -413,6 +419,7 @@ write_html_album (TGallerySetup *setup,
   block_parser_register_key (block_parser, "IMG_LIST", "IMG_LIST");
   block_parser_register_key (block_parser, "IMG_LIST_LANDSCAPE", NULL);
   block_parser_register_key (block_parser, "IMG_LIST_PORTRAIT", NULL);
+  block_parser_register_key (block_parser, "IMG_LIST_SQUARED", NULL);
   block_parser_register_key (block_parser, "LIST_SEPARATOR", NULL);
   block_parser_register_key (block_parser, "LIST_INTERSPACE", NULL);
   block_parser_register_key (block_parser, "GO_UP", "GO_UP");
@@ -454,7 +461,11 @@ write_html_album (TGallerySetup *setup,
           case INDEX_ITEM_TYPE_PICTURE:
             /*  Skip HTML code generation if it's a hidden item  */
             if (! item->hidden) {
-              s1 = block_parser_get_data (block_parser, item->gen_portrait ? "IMG_LIST_PORTRAIT" : "IMG_LIST_LANDSCAPE");
+              if (setup->squared_thumbnail_type != THUMBNAIL_SQUARE_TYPE_NONE)
+                s1 = "IMG_LIST_SQUARED";
+              else
+                s1 = item->gen_portrait ? "IMG_LIST_PORTRAIT" : "IMG_LIST_LANDSCAPE";
+              s1 = block_parser_get_data (block_parser, s1);
               replace_table_add_key_printf (local_replace_table, "ALBUM_SUBPATH", "%s/%s", item->path, setup->index_file_name);
               s3 = item_get_img_src (setup, items, item);
               replace_table_add_key_printf (local_replace_table, "IMG_SUBPAGE", "%s%s", s3, GET_EXT (setup->index_file_name));
diff --git a/src/jpeg-utils.cpp b/src/jpeg-utils.cpp
index 3bde7b6..d46e064 100644
--- a/src/jpeg-utils.cpp
+++ b/src/jpeg-utils.cpp
@@ -231,9 +231,10 @@ free_exif_data (TExifData *data)
  */
 gboolean
 resize_image (const gchar *src, const gchar *dst,
-	          int size_x, int size_y,
-	          int quality,
-                  gboolean thumbnail)
+              int size_x, int size_y,
+              int quality,
+              gboolean thumbnail,
+              ThumbnailSquareType squared_thumbnail_type)
 {
   #define ThrowWandException(wand) \
   { \
@@ -248,14 +249,35 @@ resize_image (const gchar *src, const gchar *dst,
 
   MagickBooleanType status;
   MagickWand *magick_wand;
+  unsigned long w;
+  unsigned long h;
+  unsigned long amount;
 
   /*  Read an image.  */
   magick_wand = NewMagickWand();
   status = MagickReadImage (magick_wand, src);
   if (status == MagickFalse)
-	  ThrowWandException (magick_wand);
-  if (thumbnail)
+    ThrowWandException (magick_wand);
+
+  /*  Process thumbnail if required  */
+  if (thumbnail) {
+    switch (squared_thumbnail_type) {
+      case THUMBNAIL_SQUARE_TYPE_SIMPLE:
+        w = MagickGetImageWidth (magick_wand);
+        h = MagickGetImageHeight (magick_wand);
+        amount = MAX (w, h) * SQUARED_SIMPLE_SHAVE_AMOUNT / 100;
+        MagickShaveImage (magick_wand, amount, amount);
+
+        w = MagickGetImageWidth (magick_wand);
+        h = MagickGetImageHeight (magick_wand);
+        amount = MIN (w, h);
+        MagickCropImage (magick_wand, amount, amount, (w - amount) / 2, (h - amount) / 2);
+        break;
+      default:
+        break;
+    }
     MagickThumbnailImage (magick_wand, size_x, size_y);
+  }
   else
     MagickResizeImage (magick_wand, size_x, size_y, LanczosFilter, 1.0);
   MagickSetImageCompressionQuality (magick_wand, quality);
diff --git a/src/jpeg-utils.h b/src/jpeg-utils.h
index 65e97c5..e31ed52 100644
--- a/src/jpeg-utils.h
+++ b/src/jpeg-utils.h
@@ -21,6 +21,9 @@
 #endif
 
 #include <glib.h>
+#include "setup.h"
+
+#define SQUARED_SIMPLE_SHAVE_AMOUNT 5  /* percent */
 
 
 /*  TODO: we want to have numerical values here at some point in the future  */
@@ -68,7 +71,8 @@ void free_exif_data (TExifData *data);
 gboolean resize_image (const gchar *src, const gchar *dst,
                        int size_x, int size_y,
 		       int quality,
-		       gboolean thumbnail);
+		       gboolean thumbnail,
+		       ThumbnailSquareType squared_thumbnail_type);
 
 /*
  *   get_image_sizes: retrieve image dimensions
diff --git a/src/setup.c b/src/setup.c
index 6d3c6be..daa1ff0 100644
--- a/src/setup.c
+++ b/src/setup.c
@@ -123,6 +123,7 @@ parse_setup_xml (const gchar *filename, TGallerySetup *setup)
   setup->thumbnail_landscape_height = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/thumbnail", "landscape_h", 0);
   setup->thumbnail_portrait_width = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/thumbnail", "portrait_w", 0);
   setup->thumbnail_portrait_height = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/thumbnail", "portrait_h", 0);
+  setup->thumbnail_square_size = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/thumbnail", "square", 0);
   setup->thumbnail_quality = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/thumbnail", "quality", -1);
   setup->preview_landscape_width = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/preview", "landscape_w", 0);
   setup->preview_landscape_height = xml_file_get_node_attribute_long (xml, "/gallery_setup/images/preview", "landscape_h", 0);
@@ -157,6 +158,13 @@ parse_setup_xml (const gchar *filename, TGallerySetup *setup)
   setup->feed_title = xml_file_get_node_value (xml, "/gallery_setup/feed/title/text()");
   setup->feed_base_url = xml_file_get_node_value (xml, "/gallery_setup/feed/base_url/text()");
 
+  s = xml_file_get_node_attribute (xml, "/gallery_setup/images/squared_thumbnails", "type");
+  if (s && g_ascii_strcasecmp (s, "simple") == 0)
+    setup->squared_thumbnail_type = THUMBNAIL_SQUARE_TYPE_SIMPLE;
+  else
+    setup->squared_thumbnail_type = THUMBNAIL_SQUARE_TYPE_NONE;
+  g_free (s);
+
   xml_parser_close (xml);
   return TRUE;
 }
diff --git a/src/setup.h b/src/setup.h
index 8c9927f..16665c4 100644
--- a/src/setup.h
+++ b/src/setup.h
@@ -32,6 +32,11 @@
 #define DEFAULT_INDEX_FILENAME "index.html"
 
 
+typedef enum {
+  THUMBNAIL_SQUARE_TYPE_NONE,
+  THUMBNAIL_SQUARE_TYPE_SIMPLE
+} ThumbnailSquareType;
+
 
 /*  Global gallery setup  */
 typedef struct {
@@ -52,6 +57,7 @@ typedef struct {
   gchar *img_big_dir;
   gchar *img_orig_dir;
   gchar *thumbnail_name_format;
+  ThumbnailSquareType squared_thumbnail_type;
 
   gchar *footer;
   gchar *meta_author;
@@ -65,6 +71,7 @@ typedef struct {
   unsigned long thumbnail_landscape_height;
   unsigned long thumbnail_portrait_width;
   unsigned long thumbnail_portrait_height;
+  unsigned long thumbnail_square_size;
 
   int preview_quality;
   unsigned long preview_landscape_width;