diff --git a/inc/document.class.php b/inc/document.class.php
index e5ed027db4d..83edf2b54d4 100644
--- a/inc/document.class.php
+++ b/inc/document.class.php
@@ -1623,12 +1623,14 @@ public static function getImage($path, $context, $mwidth = null, $mheight = null
       }
 
       $infos = pathinfo($path);
+      // output images with possible transparency to png, other to jpg
+      $extension = in_array(strtolower($infos['extension']), ['png', 'gif']) ? 'png' : 'jpg';
       $context_path = sprintf(
          '%1$s_%2$s-%3$s.%4$s',
          $infos['dirname'] . '/' . $infos['filename'],
          $mwidth,
          $mheight,
-         'jpg' //resizePicture always produces JPG files
+         $extension
       );
 
       //let's check if file already exists
diff --git a/inc/toolbox.class.php b/inc/toolbox.class.php
index 0f126167236..3b06c289dac 100644
--- a/inc/toolbox.class.php
+++ b/inc/toolbox.class.php
@@ -1351,12 +1351,31 @@ static function resizePicture($source_path, $dest_path, $new_width = 71, $new_he
       //create new img resource for store thumbnail
       $source_dest = imagecreatetruecolor($new_width, $new_height);
 
+      // set transparent background for PNG/GIF
+      if ($img_type === IMAGETYPE_GIF || $img_type === IMAGETYPE_PNG) {
+         imagecolortransparent($source_dest, imagecolorallocatealpha($source_dest, 0, 0, 0, 127));
+         imagealphablending($source_dest, false);
+         imagesavealpha($source_dest, true);
+      }
+
       //resize image
       imagecopyresampled($source_dest, $source_res, 0, 0, $img_x, $img_y,
                          $new_width, $new_height, $img_width, $img_height);
 
       //output img
-      return imagejpeg($source_dest, $dest_path, 90);
+      $result = null;
+      switch ($img_type) {
+         case IMAGETYPE_GIF :
+         case IMAGETYPE_PNG :
+            $result = imagepng($source_dest, $dest_path);
+            break;
+
+         case IMAGETYPE_JPEG :
+         default :
+            $result = imagejpeg($source_dest, $dest_path, 90);
+            break;
+      }
+      return $result;
    }
 
 
diff --git a/inc/user.class.php b/inc/user.class.php
index 56b1cdd509e..2df8cdd9104 100755
--- a/inc/user.class.php
+++ b/inc/user.class.php
@@ -711,8 +711,13 @@ function prepareInputForUpdate($input) {
                // Move uploaded file
                $filename     = uniqid($this->fields['id'].'_');
                $sub          = substr($filename, -2); /* 2 hex digit */
-               $tmp          = explode(".", $input["_picture"]);
-               $extension    = Toolbox::strtolower(array_pop($tmp));
+
+               // output images with possible transparency to png, other to jpg
+               $extension = strtolower(pathinfo($fullpath, PATHINFO_EXTENSION));
+               $extension = in_array($extension, ['png', 'gif'])
+                  ? 'png'
+                  : 'jpg';
+
                @mkdir(GLPI_PICTURE_DIR . "/$sub");
                $picture_path = GLPI_PICTURE_DIR  . "/$sub/${filename}.$extension";
                self::dropPictureFiles("$sub/${filename}.$extension");