items: Add option to shave image borders

A workaround for badly exported images that contain some garbage
at the borders. The amount specifies how many pixels should be shaved
from all borders (i.e. amount of 2 results in 4x4 pixels loss).

Applicable for particular items or whole album (<general> section)
with the following syntax:

    <shave amount="1" />

5 files changed, 14 insertions, 1 deletions

diff --git a/src/generators.c b/src/generators.c
index d6984be..5094086 100644
--- a/src/generators.c
+++ b/src/generators.c
@@ -318,6 +318,8 @@ metadata_apply_overrides (ExifData *exif_data,
 
   exif_data->thumbnail_crop_style = image_size->is_thumbnail ? image_size->thumb_crop_style : CROP_STYLE_NORMAL;
   exif_data->thumbnail_crop_hint = get_prop_int (items, item, PROP_THUMB_CROP_HINT, CROP_HINT_UNDEFINED);
+
+  exif_data->shave_amount = get_prop_int (items, item, PROP_SHAVE_AMOUNT, 0);
 }
 
 static char *
diff --git a/src/items.c b/src/items.c
index 0ddc3b1..7fed640 100644
--- a/src/items.c
+++ b/src/items.c
@@ -164,6 +164,7 @@ parse_album_xml (TGallerySetup *setup, const gchar *filename, TPathInfo *path_in
   }
 
   prop_xml_attr (index->properties, PROP_BORDER_STYLE, xml, "/gallery/general/border", "style");
+  prop_xml_attr_long (index->properties, PROP_SHAVE_AMOUNT, xml, "/gallery/general/shave", "amount");
   index->meta_author = xml_file_get_node_value (xml, "/gallery/general/meta/author/text()");
   index->meta_description = xml_file_get_node_value (xml, "/gallery/general/meta/description/text()");
   index->meta_keywords = xml_file_get_node_value (xml, "/gallery/general/meta/keywords/text()");
@@ -276,6 +277,10 @@ parse_album_xml (TGallerySetup *setup, const gchar *filename, TPathInfo *path_in
       }
       g_free (s);
 
+      s = g_strdup_printf ("/gallery/items/*[%d]/shave", i + 1);
+      prop_xml_attr_long (item->properties, PROP_SHAVE_AMOUNT, xml, s, "amount");
+      g_free (s);
+
       s = g_strdup_printf ("/gallery/items/*[%d]/title/text()", i + 1);
       item->title = xml_file_get_node_value (xml, s);
       g_free (s);
diff --git a/src/items.h b/src/items.h
index 24a521f..2eaf7fb 100644
--- a/src/items.h
+++ b/src/items.h
@@ -93,6 +93,7 @@ typedef struct {
 
 typedef enum {
   PROP_BORDER_STYLE,
+  PROP_SHAVE_AMOUNT,
   PROP_THUMB_CROP_HINT,
   PROP_METADATA_TZ_SHIFT,  /*  minutes  */
   PROP_METADATA_OVERRIDE_DATETIME,
diff --git a/src/jpeg-utils.cpp b/src/jpeg-utils.cpp
index d7134c2..e9e1e65 100644
--- a/src/jpeg-utils.cpp
+++ b/src/jpeg-utils.cpp
@@ -540,8 +540,12 @@ resize_image (const gchar *src, const gchar *dst,
     autorotate_image (magick_wand);
 
   /*  Don't resize if smaller than desired size  */
-  if (hidpi_strict_dimensions || MagickGetImageWidth (magick_wand) > size_x || MagickGetImageHeight (magick_wand) > size_y)
+  if (hidpi_strict_dimensions || MagickGetImageWidth (magick_wand) > size_x || MagickGetImageHeight (magick_wand) > size_y || exif->shave_amount > 0)
   {
+    /*  Shave borders if requested  */
+    if (exif->shave_amount > 0)
+      MagickShaveImage (magick_wand, exif->shave_amount, exif->shave_amount);
+
     /*  Prepare image before resizing  */
     if (thumbnail) {
       if (exif->thumbnail_crop_style != CROP_STYLE_NORMAL) {
diff --git a/src/jpeg-utils.h b/src/jpeg-utils.h
index d0664c9..b4ead79 100644
--- a/src/jpeg-utils.h
+++ b/src/jpeg-utils.h
@@ -60,6 +60,7 @@ typedef struct {
   gchar *external_exif_data;
   TCropStyle thumbnail_crop_style;
   TCropHint thumbnail_crop_hint;
+  int shave_amount;
 } ExifData;