+
+/**
+ * Detect image type of the given binary data by checking magic numbers
+ *
+ * @param string Binary file content
+ * @return string Detected mime-type or jpeg as fallback
+ */
+function rc_image_content_type($data)
+{
+ $type = 'jpeg';
+ if (preg_match('/^\x89\x50\x4E\x47/', $data)) $type = 'png';
+ else if (preg_match('/^\x47\x49\x46\x38/', $data)) $type = 'gif';
+ else if (preg_match('/^\x00\x00\x01\x00/', $data)) $type = 'ico';
+// else if (preg_match('/^\xFF\xD8\xFF\xE0/', $data)) $type = 'jpeg';
+
+ return 'image/' . $type;
+}
+
+