feature 2040 added: automatic rotation of the photo based on EXIF Orientation.

The code could have been shorter but this one 1) checks the resize dimension
with the rotation in mind 2) rotates the photo once resized to reduce memory
used.


git-svn-id: http://piwigo.org/svn/trunk@7868 68402e56-0260-453c-a942-63ccdbb3a9ee

1 files changed, 81 insertions, 21 deletions

diff --git a/admin/include/functions_upload.inc.php b/admin/include/functions_upload.inc.php
index 94116a3b4..d04e04c01 100644
--- a/admin/include/functions_upload.inc.php
+++ b/admin/include/functions_upload.inc.php
@@ -183,6 +183,9 @@ function prepare_directory($directory)
 
 function need_resize($image_filepath, $max_width, $max_height)
 {
+  // TODO : the resize check should take the orientation into account. If a
+  // rotation must be applied to the resized photo, then we should test
+  // invert width and height.
   list($width, $height) = getimagesize($image_filepath);
   
   if ($width > $max_width or $height > $max_height)
@@ -193,6 +196,48 @@ function need_resize($image_filepath, $max_width, $max_height)
   return false;
 }
 
+function get_resize_dimensions($width, $height, $max_width, $max_height, $rotation=null)
+{
+  $rotate_for_dimensions = false;
+  if (isset($rotation) and in_array(abs($rotation), array(90, 270)))
+  {
+    $rotate_for_dimensions = true;
+  }
+
+  if ($rotate_for_dimensions)
+  {
+    list($width, $height) = array($height, $width);
+  }
+  
+  $ratio_width  = $width / $max_width;
+  $ratio_height = $height / $max_height;
+  
+  // maximal size exceeded ?
+  if ($ratio_width > 1 or $ratio_height > 1)
+  {
+    if ($ratio_width < $ratio_height)
+    { 
+      $destination_width = ceil($width / $ratio_height);
+      $destination_height = $max_height;
+    }
+    else
+    { 
+      $destination_width = $max_width; 
+      $destination_height = ceil($height / $ratio_width);
+    }
+  }
+
+  if ($rotate_for_dimensions)
+  {
+    list($destination_width, $destination_height) = array($destination_height, $destination_width);
+  }
+  
+  return array(
+    'width' => $destination_width,
+    'height'=> $destination_height,
+    );
+}
+
 function pwg_image_resize($result, $source_filepath, $destination_filepath, $max_width, $max_height, $quality)
 {
   if ($result !== false)
@@ -222,36 +267,45 @@ function pwg_image_resize($result, $source_filepath, $destination_filepath, $max
   {
     die('unsupported file extension');
   }
+
+  $rotation = null;
+  if (function_exists('imagerotate'))
+  {
+    $exif = exif_read_data($source_filepath);
+    if (isset($exif['Orientation']) and preg_match('/^\s*(\d)/', $exif['Orientation'], $matches))
+    {
+      $orientation = $matches[1];
+      if (in_array($orientation, array(3, 4)))
+      {
+        $rotation = 180;
+      }
+      elseif (in_array($orientation, array(5, 6)))
+      {
+        $rotation = 270;
+      }
+      elseif (in_array($orientation, array(7, 8)))
+      {
+        $rotation = 90;
+      }
+    }
+  }
   
   // width/height
   $source_width  = imagesx($source_image); 
   $source_height = imagesy($source_image);
   
-  $ratio_width  = $source_width / $max_width;
-  $ratio_height = $source_height / $max_height;
-  
-  // maximal size exceeded ?
-  if ($ratio_width > 1 or $ratio_height > 1)
-  {
-    if ($ratio_width < $ratio_height)
-    { 
-      $destination_width = ceil($source_width / $ratio_height);
-      $destination_height = $max_height; 
-    }
-    else
-    { 
-      $destination_width = $max_width; 
-      $destination_height = ceil($source_height / $ratio_width);
-    }
-  }
-  else
+  $resize_dimensions = get_resize_dimensions($source_width, $source_height, $max_width, $max_height, $rotation);
+
+  // testing on height is useless in theory: if width is unchanged, there
+  // should be no resize, because width/height ratio is not modified.
+  if ($resize_dimensions['width'] == $source_width and $resize_dimensions['height'] == $source_height)
   {
     // the image doesn't need any resize! We just copy it to the destination
     copy($source_filepath, $destination_filepath);
     return true;
   }
   
-  $destination_image = imagecreatetruecolor($destination_width, $destination_height);
+  $destination_image = imagecreatetruecolor($resize_dimensions['width'], $resize_dimensions['height']);
   
   imagecopyresampled(
     $destination_image,
@@ -260,11 +314,17 @@ function pwg_image_resize($result, $source_filepath, $destination_filepath, $max
     0,
     0,
     0,
-    $destination_width,
-    $destination_height,
+    $resize_dimensions['width'],
+    $resize_dimensions['height'],
     $source_width,
     $source_height
     );
+
+  // rotation occurs only on resized photo to avoid useless memory use
+  if (isset($rotation))
+  {
+    $destination_image = imagerotate($destination_image, $rotation, 0);
+  }
   
   $extension = strtolower(get_extension($destination_filepath));
   if ($extension == 'png')